Popeye75

Hi everyone, i'm new to this forum, but this is my 3rd f-body. This particular car is an 85 firebird with the tpi v-6. this car is seriously mickey moused everywhere, but it was hard to pass up for 200 dollars with a clean body! i can handle the fuel pump wired with speaker wire and the screwey brake light wiring, but the main problem is that the car won't stay on for more than a few seconds and if you give it any gas at all it immediately dies. this car has been sitting for 3 years or so, but for now i wanted to get it going just to drive the 15 miles or so home and really go through her with a fine tooth comb and get everything fixed up right. the guy i bought it from says he was driving it right before he parked it(for 3 years). i put about a gallon of gas in it and a fresh battery. the car wouldn't start and we found out the coil was bad. put that in and it started right up. for 5 seconds. then it died and it keeps doing that. i realize i need all new filters(gas, oil, air, etc.) but i really need to have this car out of where it's at and to my house. i really, REALLY wanted it to move under its own power but i'm tapped for ideas. did i mention the vacuum equipment is garbage? i've been trying to get the stuff re-routed, but it's a mess. any suggestions on what components could specifically be causing the engine to die out? if you start it with your foot off the gas it'll idle for 5 to 10 seconds, but if you even lightly touch the gas she dies immediately. i looked at the vacuum diagrams on autozone.com but they're in black and white and you can't really tell accurately every connection, plus i think the previous owner might have removed some of the vacuum equipment since i can't get a for sure diagram for my car(it's the 5 spd by the way). i'm still looking around in the forums, but if anyone's got some suggestions please help! she's my first t tops and i can't wait to get her home and clean her up for that first topless cruise!
uh... sorry so long, had to get the full story up there!

Scramby

I'm kinda in the same boat as you. See my plea for help: https://www.thirdgen.org/forums/tech...ra-issues.html If the car has been sitting for three years, it's probably a good idea to start with an initial tune-up, which I'm doing in hopes of restoring my f-body back to it's original condition.

I'm guessing that the reason your car dies when you hit the gas is because of a fuel related issue. By that, I mean, your trying to inject more fuel to mix with more air, but not getting the fuel you need to keep the engine running. I would look at fuel pressure first. If your fuel pressure is low, change the filter and recheck it. If it's still low, change the pump. If your pressure is fine, maybe start looking at your injectors.

Good luck!

CamaroRider

I have a 1989 Camaro. In Feb of 2007 (year and a half ago) it E-checked fine. A few days ago (a year and a half later) I tried to start it. It would sound like it would start by then die. I finally tracked it down to a crack in the 1.75 inch flexible hose connected between the fuel pump and the hard line (inside the tank). The pump itself sounded fine and pumped well if there was no pressure required. When hooked to the carburetor and the pressure tried to build up it would squirt fuel back into the tank (on the inside of the tank). I replaced the short hose with 1.75 inches of NAPA H213 (submersible and rated SAE 30R10). The car started after the hose was replaced. So check your fuel pressure and make sure you are getting somewhere around 11.0 PSI. If not then this could be caused by a clogged fuel filter, clogged fuel lines, bad 1.75 inch rubber coupler (as mentioned) or bad fuel pump. (I am assuming you can hear the pump run and that you have fuel in the tank.)

Popeye75

yeah, i have been wondering about the fuel pressure, but was inclined to replace the filter at home. looks like i'm going to have it towed today sometime and i'll defanitely start looking harder at the fuel system. i should mention that if you push the gas just a little and then turn the key it will rev up a little just for a couple of seconds, but i don't see how that eliminates the possibility of that little fuel line like you were talking about or other leaks in the fuel system. the fuel pump had been replaced before the car was parked(they cut out a square in the trunk to get to it rather than lower the gas tank!). i was hoping that i had a dirty throttle position sensor or an easy fix with the vacuum lines just to get the car home. once i get her home i'm tearing all this half-*** work out and getting this stuff done right!
anybody know any vacuum issues that could cause these systems? the only vacuum line i think that's hooked up right is the brake booster off the manifold! =( any sensors that could cause this? something in the throttle body? where's the throttle position sensor and could it cause this?
thanks a lot for all the help so far. i'll defanitely take a look at the fuel pump and the 1.75 feed line as mentioned above.

CamaroRider

If you can pull the fuel pump through the access hole then I would most definitely do that and thus either find a problem OR eliminate that completely as a source of problems. When the small connecting hose was giving me a problem the car would only run if I punched the gas TWO TIMES and waited 2 seconds, over and over. Any other combination would cause the engine to die. I had cleaned my TBI injectors and cycles them so I knew they were not a problem. So I concluded it was a fuel feed issue. I could hear the fuel pump and it sounded fine. So I cut an access hatch and pulled the fuel pump system. I only needed a 1.75 inch piece of the H213 but I had to buy a minimum of 1 foot !!

Popeye75

fun stuff. so i pulled the fuel pump out of the access hole the previous owner had cut in the trunk floor. first off, they had cut the hard lines coming out of the pump and re-connected them using a piece of rubber hose and clamps. normally there is a feed and a return line coming from the top of the fuel pump assembly. this vehicle has four hard lines coming from the top. wth? i pulled it up and two of the three wires in the assembly aren't hooked up. so, i re-connect all that and can't help but wonder how the hell was it getting gas in the first place? how was i getting enough gas to keep starting, even though it would die right away. the guy i bought this car from swears up and down that he drove it to wear it was when i bought it. i really think it's just a dirty sensor having sat for so long, but i really don't know what to think. i've never had such a big problem with vacuum that the engine would die that fast. i've heard of them 'hunting' or running rough, but not dying in like 3 to 5 seconds. i'm really at a loss here guys, any suggestions? does anyone think it could be the throttle position sensor or something to do with the idle? all i did so far was check fluids, add clean gas, and spray a bottle of choke cleaner into the front of the throttle body, but maybe i need to take some things off to clean them? anyone have a good vacuum diagram? the one i got off this site so far was not very detailed and hard to make out where the t connections are. thanks in advance for any help.
-Chris

CamaroRider

If you look down on the fuel pump assembly from the rear of the car the 4 tubes on my Camaro are (going from passenger side to driver side ** ):

- 'Fuel' feed to the carburetor (with pressure in fuel injected cars)
- 'Return fuel' from carburetor fuel regulator and to the tank
- 'Fuel vapor' directing vapors to the Vapor Storage Canister in the front of the car. In my car on the driver's side near the headlight.
- 'Ventilator' hose from the Ventilator Assembly located in front of the fuel tank

** But you should trace these lines on your car in case they differ from mine for some reason.

Since your engine (I think) is a TPI I would expect your fuel pressure to be about 40 PSI. I wonder if your fuel pump is providing that kind of pressure.

VAN454

is it running VATS? My 88 GTA started doing a similar thing, and it was the VATS, I bypassed it and it started fine after that

Popeye75

what's VATS? i'm still learning about these cars and i'm not familiar with that term yet or how to bypass it. how would i go about bypassing it to see if mine will start?
as far as the four tubes coming from the fuel pump then the two on the left (looking down and from the rear of the car) should go to the vacuum canister all the way forward on the passenger side under the hood?

VAN454

Vehicle anti theft system. I don't know if the 85's had it, have a look at your key, if it has a little chip in it then it's got VATS

impaled

VATS came along a few years later. IIRC around 1989 or 1990

Popeye75

ya i guess no vats then. besides, i didn't get the original key with the vehicle i had to remove the lock cylinder from the column and put in a autozone replacement. any other ideas? i guess i'm having it towed to my house in the morning, but i need to get it up and running so that i can get emissions done and get her on the road.
i've been looking around for info but can someone tell me for sure if the v-6 had a different 5 spd trans than the v-8? am i going to kill this tranny if i take out the v-6 and switch over to a 350 small block i've got laying around? fyi it's got stock heads but i'll probably toss in a summit street/strip cam(not too radical, just what the stock heads can handle), intake, carb and maybe some headers if i can find a good deal. i hate to chuck the transmission, but it does me no good to do all that work and blow the transmission on my first time driving her!
the main priority is daily driver, but i'd like to eventually go to the track. i've got a feeling though that i probably won't be too abusive to the trans until i get some aftermarket heads later this year...

Scramby

The first step would be to identify the transmission then. Check your RPO codes to see what you should have had installed initially and verify that's what you actually have. From there, you should be able to run some numbers.

darkride86T/A

Does the car have idiot lights or gauges? If the car has fuel injection, make sure the oil press. sending unit connector is hooked up. GM made it so, if the ECM detected no oil pressure in FI cars, it would cut power to the fuel pump as protective measure. The car would start but cut off after 5-10 seconds. I know this is the case for the LO3 TBI cars, but I'm not sure about TPI cars or the MPFI V-6 cars. If not that, then maybe the TPS or EGR valve. Just my.
Hope the info is helpful.

VAN454

Definatly before that, my '88 has it

CamaroRider

I modified my post concerning the four tubes that exit the sending assembly.

The first item is the fuel being pumped out to the carburetor. In a fuel injected system this will have fuel pressure built up when the pump has been running. A check valve in the fuel pump keeps pressure in the line even after the pump is shut off. However tiny 'weep holes' in the carburetor will slowly reduce the pressure in the line over time after the pump has stopped pumping. But caution should be used when dealing with this line so that it is not tampered with while the pressure is high.

The second item is the 'return fuel' from the pressure regulator on the carburetor and the discharge from the 'weep holes' in the carburetor as mentioned above.

The third item send vapors to the Vapor Storage Canister. In my 1989 Camaro this is located on the driver's side, way up front behind the headlight. I see some type of valve in the same line just before the canister.

The fourth item is for air to enter the fuel tank from a one way valve located in front of the gas tank and just hangs down to a small bracket. It is white plastic and is quite easily seen when one looks in that general area.

impaled

my '87 didnt, so it must have started in '88

Popeye75

darkride, my car has dummy lights and the mpfi with the throttle body up front, not carb or tbi. i'll defanitely look into the oil pressure sender when the car is towed to my house in a few hours. does anyone know an easy way to test the egr and where it's actually SUPPOSED to be routed too? my vacuum hoses and routing are a hot mess and i need to start over from scratch. as far as the throttle position sensor, is that what's located under the throttle body with a vacuum port coming out of each side? if not, then what the heck is that?

camarorider i defanitely need to get my hoses coming off the fuel pump assembly re-run as they are fubar. i'm pretty sure my canister is on the passenger side but will take a closer look when i get the car back here later today. thanks all of you for the help so far and with eliminating some possibilities already.
-Chris

Popeye75

dang it, same problem only now it's worse. so i went through and took off all the vacuum stuff and the top intake manifold top to make sure i got it all. i put everything back together and re-installed a few missing pieces that i had to scrounge around for. i made the mistake of not paying attention when i took the spark plug wires off to replace those so i had to get that straightened out. now i have all the vacuum equipment and hoses right with the exception of the two hoses that route to the vacuum canister from the top of the fuel pump assembly. i checked to make sure i have power to the fuel pump, but now the car will only start for a second when i spray starting fluid in to the throttle body. so... gotta figure out the fuel problem!!! but after that not sure what else this punk is gonna need. anybody have a diagram of the routing for the oil pressure switch? it's there, but this harness is a mess with shorts and wires spliced together all over=( i'm still working on it, but not making a lot of progress. i have the car at my house now, but i couldn't get it to fire for even a few seconds until tonight. where can i test the signal FROM the oil pressure sender? at the cpu? what should it be? i'm beginning to not-like this car a little. somebody help me!!!

Popeye75

ok, so i checked the 3 wires heading into the fuel pump and of course the black one is a ground, the red wire has power with key-on, but the tan wire has nothing. so i get into the wiring diagram in the back of the hanes manual and it shows that the tan wire is from the oil pressure sender! so, my oil pressure sender is hooked up but i have an open or ground somewhere on board. my question is- Can I temporarily bypass this to verify the pump(and engine and car) are good? can i use a key-on accessorie from the fuse panel to provide power to the tan wire or does it use a different signal? how can i bypass this??!!!! somebody please, i'm so close!!!!!!!

Popeye75

ok, i cut the tan wire to the fuel pump, then ran a wire from key-on accesorie to the tan wire on the fuel pump. now i FINALLY here the fuel pump kick on and the car now fires up and stays on but when she settles into idle she idles really rough. that's ok for now because the car hasn't been driven in 3 years, so i'm sure it'll smooth out as it runs a little longer. the thing is, i'm sure the pump is only supposed to prime for 2 or 3 seconds when the key is initially turned on, know what i mean? like normally you turn the key forward and you here a 'whir' noise for a second or two as the pump primes. the way i have mine rigged now you can here the pump the entire time the key is on. this can't be right. does anyone know how i can circumvent this without having to run through the entire wire harness from the oil pressure sender? does the signal from the sender change? on my schematic i looked at it shows the sender to the pump, but does it run through the ecm or anything? i mean could i safely cut the wire after it leaves the actual sender on the drivers side of the engine and run a wire to the tan wire in the fuel pump and accomplish the same thing? is there anything altering the signal? please help!!! when she started she sounded great and i can't wait to go for a ride but it would be really incovenient for the gas tank to explode and light me on fire... lol.

drknow90rs_ss@y

iTrader: (3)

I've never had my fuel tank explode, but I can imagine it would be very annoying! It would, however, make a nice u-tube video, if some one happens to catch it on camera.... How much fuel is in the car? It should prime, at most for 5 seconds. To be honest with you, my cars all keep their prime, at least, overnite. It sounds like you have a fuel problem, still. I, personally would go get a new fuel sending unit from checker or napa. your problems could be the rubber hoses they put the hard lines back together with. If they are not "Fuel" lines then the rubber will break down, sending particles through the fuel filter (Clogging the fuel filter, along the way) and eventually clogging the regulator and injectors. I suspect the last owner didnt want (Or know how) to replace the fuel pump relay so he by-passed the relay with his "Custom" wiring job. It's the middle relay on the drivers firewall next to your brake booster.
Hope this helps!

naf

iTrader: (7)

You provided constant power to the fuel pump by bypassing the oil pressure switch? And now the pump runs continuously with key on?

The system is designed to run the fuel pump for a few seconds with key on then switch power over thru the oil pressure switch. This allows you to start it (with no oil pressure) but will also kill power to the pump if the engine stops running but the key remains on (a nice to have feature in the event of a wreck).

Diagnose the problem with the circuit thru the oil pressure switch. Easy enough to do while you've got the switch bypassed. Check continuity thru the oil pressure switch with the engine running, then the rest of the circuit.

I'd change the oil first thing though. Heck that may be your problem with whatever is still in there after a few years.

CamaroRider

I am getting lost when you mention 'sender on the driver's side of the engine'. Do you mean the FUEL PUMP RELAY ?

For the fuel pump to work on my 1989 305 FI Vin E (TBI) the fuel pump is controlled by two devices: The 'fuel pump relay' and the 'oil pressure switch'.

The 'fuel pump relay' can be triggered in three ways:
1. A wire you can place in the ALDL connector that has +12 volts will run the fuel pump but this is not the way you would normally run your fuel pump.
2. The ECM can trigger the relay. This is what supplies the 'two second operation' that you mention. It is tied into the initialization of the ECM when you turn the ignition key from OFF to RUN. And it suplies +12 Volts during the CRANK phase, and from what I just found out it continues to keep the relay activated even during normal running of the engine (that was a surprise to me).
3. The 'oil pressure switch' will supply +12 volts to the fuel pump if the oil pressure reaches at least 6 PSI. This switch is in PARALLEL with the relay supplied +12 volts (if the relay is energized at that time).

The ECM ALSO monitors the voltage going to the fuel pump. This sensing wire is connected to the tan wire that goes to your 'fuel pump relay' and 'oil pressure switch'.

The three wires coming from the fuel sending unit are:

1. A ground. From what I understand it does NOT go directly to the battery post. It was mentioned that it goes to a bolt under the back seat (driver's side) and then through ground straps, cables, connectors ... wow.

2. A fuel level sensor wire. This is changed by the floating arm in the fuel tank. The arm is hooked up to a variable resistor 'wiper' and sends some voltage between +12 volts and ground that is interpreted by the fuel gage.

3. The +12 volts wire that feeds the fuel pump and variable resistor. The fuel pump and variable resistor are in PARALLEL inside the fuel tank.

After reading that, if you have anything that you would like discussed in more detail just ask. Once you grasp the circuit I am sure you will see how simple it is.

Popeye75

alright, the oil pressure switch(?) just above the oil filter was not hooked up on this car. also, the single wire switch just above that is not even on the engine! i got them both and now i'm gonna throw 'em on and see if that restores the signal i'm missing. i should mention that i tested the fuel pump relay and it wasn't receiving the signal from the oil pressure sender. i'll keep you guys posted.

Popeye75

hmm... no luck. the only way to get the car to run is to manually connect the tan wire on the fuel pump to get it to prime and run. with that hatch cut into the trunk area above the fuel pump it's weird to hear the fuel pump like that. i'm used to hearing the pump prime in any other car i've owned and then after that first two seconds you don't hear it anymore. the way i rigged it up you hear it come on with the key and stay on constant. it's a little disconcerting=( i hooked up the oil pressure sender to what i think are the correct wires and i still get no signal from the fuel pressure switch (on the firewall/driver side) but everything else is testing good right up until the oil pressure sender. so... the two wires that run to my oil pressure sender are orange and tan i think. one has 12 volts on it when the key is on. i need some help in isolating the problem here. i really would not put it past this car to have either a ground in this circuit or even a cut wire. is there a way to run the oil pressure sender switch(to be clear the switch above the oil filter) to the fuel pump relay(on the d.s. firewall) and then back from there to the fuel pump? is there anything else in this circuit i have to worry about? what about the ecm?
also, the three wires leading into the fuel pump assembly are black, red and tan, but which is the fuel level sender? my fuel gauge is pegged out but i only have about a gallon in it. i have power to the red wire but nothing going to the tan. ever. not key-on, not for two seconds, nothing. only when i by-pass.
----------


wasted connector to the old oil pressure switch. i cut off the end and spliced in a new non-melted connector and attached it to the new sender.

CamaroRider

The color of your wires might vary from mine but I will deal with my wires in this post. *See note at bottom

I will have to discuss my 1989 305 FI Vin E (TBI):

First of all you should place about 5 gallons of fuel in the tank to make sure the fuel pump is actually submerged in fuel. That will also cut down on the sound level of the pump. And the fuel pump will stay cooler.

Here is where I would start: The fuel pump relay.

On that relay there are 5 wires.
The ORANGE wire is the fused +12v wire. That wire will transfer the voltage to the TAN/WHITE wire ONLY when the relay is energized.

The relay is 'activated' by using two of the wires on the relay. The GROUND is BLACK/WHITE. The DARK GREEN/WHITE wire comes from the ECM and carries the 'activating +12v voltage' for the relay.

The RED wire goes to my 'G' terminal of the ALDL connector.

What you first need to do to get organized is make sure you have a connection between the 'Fuel Pressure Switch' TAN/WHITE wire to the 'Fuel Pump Relay' TAN/WHITE wire. This wire also should be running to the ECM 'B2' connection and is tagged 'Fuel Pump Signal (Voltage Monitor)'.

And also note that the ORANGE wire that goes to your 'Oil Pressure Switch' is +12v and is fused by the same fuse as the Fuel Pump Relay.

Once those TAN/WHITE lines are connected and you have +12v on each of the ORANGE wires mentioned above, then you need to test the Fuel Pump Relay. Turn the key from OFF to RUN. Listen for the two second run. If you hear it run for 2 seconds it just proves that the ECM is sending a signal to the relay and the relay is 'actuating' for two seconds as a response.

On my car I found that when the engine is started and RUNNING the ECM is constantly keeping the relay 'activated'.

To test the fuel pump connection to the relay when the engine if OFF (ignition key is removed) you can run a +12v wire from the battery to the 'G' connector on the ALDL connector. When the +12v contacts the 'G' terminal the voltage goes through the => INACTIVE <= relay, using the 'default contacts' of the relay (called 'Normally Off' contacts), and goes to the TAN/WHITE wire of the relay and thus turns on the fuel pump.

*Remember my car is a 1989 Camaro 305 FI Vin E (TBI) and thus my relay wire colors and ALDL connector are being used. Your vehicle might have different color wires for these wires and your ALDL connector might have different contacts which are more appropriate.

Popeye75

i have 12 volts going to the oil pressure switch above the oil filter, and i have power to the orange wire in the fuel pressure regulator and everything matches up same as your car except when i get to the 'G' terminal on the aldl i have no power. i DO NOT get the 2 second power on when i turn the key to the 'on' position. this is the problem i'm trying to overcome. i just found a turbo that i would love to throw on this car but not if i can't get the basics sorted out!!! i'll post more when i can, but anyone have any suggestions?
i need the pump to prime on its own, what the heck is going on with this thing?

CamaroRider

Well the 'G' terminal of the ALDL connector on my car changes depending on how the relay is set at that moment.

When the relay is NOT actuated then the 'G' connector (via the RED wire to the 'fuel pump relay') connects to the TAN/WHITE wire of the relay. So when the ignition is OFF you could (if properly hooked up) take a wire from the +12 volt battery terminal and hook it to the 'G' terminal and you will be placing +12 volts directly onto the TAN/WHITE wire. When that TAN/WHITE wire is properly installed, it will connect to the 'oil pressure switch' AND the fuel pump +12 volt wire. So you can look at this as a possible THIRD source for +12 volts to run the fuel pump.

Also, as mentioned previously there would normally be a TAN/WHITE wire that also would connect to the ECM to 'monitor' that TAN/WHITE circuit.

Once those connections have continuity then the only thing needed would be for the ECM to 'activate' that relay at the proper time. The first test to see if the ECM truly is running the relay would be when you hear the fuel pump run for two seconds when you turn the ignition key from OFF to RUN (but do not start the engine).

The second test to see if things are fully operational is to turn the key from RUN to the CRANK position and see if the engine starts with proper fuel delivery.

When the relay is 'activated' the 'G' terminal will then have NOTHING hooked to it except the relay contact itself which is NOT being used at that moment (it will be 'floating in space' so to speak).

Now another good check would be for you to test the DARK GREEN/WHITE wire at the relay for the presence of +12 volts (the BLACK/WHITE wire on the relay is the ground reference for the relay) for two seconds when the ignition key is changed from the OFF position to the RUN position (do not start the engine). If you see that two second change in voltage at the DARK GREEN/WHITE wire but the relay is NOT energizing and thus the fuel pump does not energize and you know the wires are all hooked up correctly then I would suspect there is a problem with the relay windings. The relay SHOULD have 'actuated' and caused the ORANGE wire to connect to the TAN/WHITE wire and thus to the fuel pump. The relay windings might be 'open' (the coil might have been burnt out thus 'open'). There is also possibility that the coil is SHORTED thus the relay will NOT 'actuate'.

Popeye75

ok, got all the vacuum stuff hooked up the way it shows on the diagram. car started and i took it for it drove but it felt real rough and lots of hesitation, especially trying to make a u-turn and come back up my street. got home and i put a few more gallons of gas in it and ran some seafoam in it. 1/3 in the gas, 1/3 in the oil, and 1/3 in the pcv valve. it smoked like a mother!! i mean it smoked so much the first time i ran it i shut it down because i thought someone would call the cops! i waited a while and warmed her up again and still more. this went on again and again all morning and finally she let up on the smoke. runs a little smoother but now my car turned into Christine!
Now the car is reving up pretty high then she slides back down til she sounds like she's gonna die out, then right back up to a high rev and back and forth. after 5 minutes or so she eventually settles down into a rough idle, but still not so good=( this is called 'Hunting' isn't it? My thought is a pretty decent sized vacuum leak. any ideas what could be causing this? i'm gonna spray some wd-40 or starting fluid around the engine and see if it'll rev up. wd-40 will work right? not excited about spraying starting fluid on an engine that's been idling for 10 minutes. lol. also, does anyone know what i should be looking at for a minimum cylinder compression if i want to try a turbo? i'm talking lbs/ft that you get from a cylinder compression checker that i rented from auto zone. thanks for all the help so far guys.

Popeye75

oh yeah!!! i went down to the junkyard in search of a new hood since mine is bent all to hell and i came back with a turbo off of a ford probe and an intercooler from a volvo! now.... can anyone tell me how the h*ll to run a fmu? also, there should have been a blow off valve on the ford, right? where? i want to just use the fmu and blow off valve from the same vehicle but can someone tell me what i'm looking for? not looking for a ton of boost, just a little more power than stock. maybe 80 to 100 more? is that feasable with this set up or do i need to upgrade my injectors?