Keoman

iTrader: (3)

What has been done:
Top End rebuild. Had valve job done on heads. Hot tanked intake manifold & runners. New parts include IAC motor, Push Rods, Distributor (cap, rotor, ignition control module), Spark plugs (NGK vpower), Bosch plug wires, Head Bolts, Head Gaskets, IM Gaskets, TB gasket.

Problem:
basically, the car runs horrible. Acts like the timing or firing order is off. Backfires a little. I can barley get the car started. At least half throttle required to get the car running, after the car is running I can back off a little but the car shutters bad and dies if you let off completly.

I have checked the timing at least 10 times along with the spark plug connections and routing. While timing the car, I disconnected the single wire connection (EST wire?) out of the engine harness with no positive outcome. I removed the AIR pump and plumbing from the car. I have replaced/cleaned almost every part I took out of the car.

One mentionable flaw I made was when i tried to start the engine for the first time. I forgot to connect the main ground connection to the block. The only connection was the strap on the back of the pass. head to the firewall by the coil. The wire started smoking and I promptly quit cranking, figured it out and hooked the ground back up.

The reason I post this in the ECU section is I have tried everything I can think of with no results. The SES light comes on solid with the EST connection disconnected like it should. If The EST is connected and pins A&B are bridged, the ECU flashes code 12 as normal.

My question is, is the ECU messing with my car or not?? Why doesn't it run like it did before the rebuild?

Thanks in advance

Six_Shooter

iTrader: (2)

Sounds like the ECM is fine.

Sounds like a mechanical issue to me.

Are you sure the dizzy isn't 180* out? SBC will most of the time run exactly how you describe if the dizzy is 180* out.

All injectors plugged in? No pinched hoses, etc?

Keoman

iTrader: (3)

Here's where I'm at.
http://www.youtube.com/watch?v=sas31sYMU5c

Temp sending unit is broke and the fan switch is also broken. Fans are on 100% of the time and no reading on temp gauge.

nebulous

I was about to post a question about 7730 testing myself, and this thread drew my attention. For what it's worth, when I did my engine swap I forgot to connect the ground cable and toasted my last 7730, so that could be it.

DeathStarr89

iTrader: (1)

was that your check engine light flashing the whole time?

If it's flashing with out a code key in the OBD port there is really something wrong. I've seen that happen on a 1227730 with shorted inputs and on a car with a few poorly connected ECM grounds.

Keoman

iTrader: (3)

Thanks nebulous,
I am definatly going to get another ECM.
I hope this solves everything because my car is acting some kinda weird that i never seen before.

Keoman

iTrader: (3)

Purple,
for the life of me I cannot remember if I had the pins bridged while the car was running like that. It has to be the ECM though, seriously. I have tried so much Its giving my nightmeres.

DENN_SHAH

iTrader: (1)

the temp gage uses the sending unit in the left head.
the ECM uses the temp sending unit in the intake up near the T-stat.
if the wire for the fan switch is grounded, it will turn the fan on all the time.
if the ECM thinks it sees a problem with the coolant temp sensor circuit, it will turn the fan on all the time.
also, if there is a problem with the temp sensor for the ECM, it can cause the motor to run poorly. coolant temp is a major input for fuel control in open loop. a shorted or open coolant sensor circuit will keep the ECM in open loop.

RBob

iTrader: (1)

Still have the Multec injectors in the engine. I'd be surprised if they were still good. The coils short out. Can check them hot, must be over 12 ohms.

As for the flashing SES (lower right of dash), the ECM may be in limp mode, not running from the PROM. Or, A & B are still shorted and it is doing the rich/lean blink.

Since you can flash codes, I'll go with the rich/lean blink.

With the MAF set ups the minimum air and TPS settings are critical.

RBob.

Keoman

iTrader: (3)

Ok Denn,
What you said here, in my opinion is very applicable to my situation. I don't know who it was but somebody seriously messed up the connectors on both sides of the heads. I reached down and just barely touched the Connector on the drivers side head and it came apart.
After, I went over to the passenger side and again reached down and wiggled the conector and it seems that the sensor itself is broken. My question is where can I get another connector for the sensor?


Rbob,
Thanks for the info. I checked my injectors by prodding the leads with the ohm-meter but I kept getting a 0 ohm reading. I tried 3 and figued I was doing it wrong. How should I check them? Also, I cannot remember if pins a & b were bridged or not while it decided to work.

As of right now the car will no longer idle and continues to be very difficult to keep running. I have a buddy that is an EFI genius that might be able to take a look this weekend.

I have an OBD to USB cable and a laptop guys! Tell me how I can test this ECM or at least monitor the readings and find out what the he'll is going on.
Thanks
Keo

RBob

iTrader: (1)

For observation of data use WinALDL: winaldl.joby.se/

It is only 160 baud but is simple to get up and running.

For checking the injectors, put the DVM on a low ohms scale. Touching the leads together should show less then a 1/2 ohm.

Unplug the connector from the injector and place a DVM lead on each of the two terminals of the injector. Read the meter, should be above 12 ohms. If not then the injector is bad.

RBob.

Keoman

iTrader: (3)

Great, thanks. Ill check everything and post my findings.

85 ZXX

iTrader: (1)

Sorry to hear about the engine trouble Keo, I know you are very thorough on what you do.

I had a similar problem and I had to push MY reset button and check all of the basics again. I went over everything from one side to the other and front to back.

I had small vac leaks, #8 injector had no Ohm reading, O2 sensor was bad, mass airflow boot had small cracks in it, EGR valve leaked, intake gaskets were bad, and I had two plug wires on the wrong plugs.

I did upgrade to Bosh III 24lbs injectors from F.I.C though. I really like them.

Keep us posted my friend.

ninetyone

iTrader: (2)

I had the same problem last week. Car would die if i took my foot off of the gas. Fan was running all time, and it sputtered and backfired. Will your car ping and knock if you take it past 3k rpm? Anyway, it passed the blink test when you first turn the key to the on position. Have you tried disconnecting the ecm altogether? all three connectors? I heard that resets the ram inside,but it needs to be disconnected for 10 min. or so. I ended up getting a new prom burned,but it still acted up,so i held my foot on the gas for about 10 min and let it idle and walla! my car has been running normal since. I think i have an intermittent problem with my ecm. You can also try swapping out your fuel pump relay with one of your fan relays,but i think your problem is a bad ecm or wiring.

ninetyone

iTrader: (2)

Does your car seem like it's stuck in diagnostic mode? sounds like it. Try another ecm.

85 ZXX

iTrader: (1)

I had a 87 Chev pick-up with a TBI 305 and the ECM went bad while driving. The engine spit, sputtered and backfired. I managed to limp to the Chevy dealer and they replaced the ECM. That was 18 yrs ago and it cost $400.00.

Keoman

iTrader: (3)

Ninetyone,
We are definatly in the same boat. I have the same nasty idle and running issues as you are describing.

85 zxx,
I am sure those ECM's new are rediculously expensive.

Here is where I am at as of right now.

My dad went to the JY and was able to find a 165 ECM for me. *Three Cheers* So I went out and proceeded to swap the two. I noticed that mine was infact not a 165. It is a 16198259. So I did a little research and found that people had said it was an interchangable part number. So i put it in the car and IT STARTED IDLING! Horay...

However my problems are as follows:
1) Idle is super speratic. Jumps up and down from 2k - 900 RPM's w/ EST wire connected.
2) W/ EST wire DISCONNECTED, still jumps around idling.
3) I tried to plug in my ALDL cable and get some readouts on things, ECM does not seem to respond at all.
4) Cold or hot, when you jump the throttle quickly, the car boggs and then rev's. Some times worse than others. I will take somemore video of this.
5) Car runs almost perfect with the EST wire disconnected, right at 6* advanced. (except for problem 3)
6) the passenger side fan does not turn on. (not too concerned w/ this, probably the broken connector)
7) My A/C pully wines like a B.. (irrelavent I know, I just felt like getting it out of my system)
8) Last but not least, I CANNOT pull codes from my ECM. The SES light does NOT come on while the car is running, however badly it may be.


Now for what I have checked.
1) TPS voltage reads .54 exactly.
2) Injectors all read between 16.8 -17 Ohms


Now my biggest questions are,
1) How does my ECM (the 165) differ from the one I pulled out (the 259)
&
2) Could I possibly need a new PROM chip to go with my new ECM? Could the short have damaged it as well?

Thanks for the input guys.

Keoman

iTrader: (3)

Oh NinetyOne,
May I ask what initially caused your problem? Had you done work on the car? Was it out of the blue? Messed with something?

ninetyone

iTrader: (2)

It was out of the blue basically

ninetyone

iTrader: (2)

Try another prom too, if yours is a 305 car, they are not too hard to find. How are your engine grounds? They are behind your heads.

85 ZXX

iTrader: (1)

When I start having problems with my 85 Bast**d ECM again this is what I'll upgrade to.

http://www.painlessperformance.com/w...rchField=65104

Keoman

iTrader: (3)

I went out and double checked the grounds on the heads, all good there.

My car is an L98. I am going to take it over to the dealership and have them diagnose it. Probably the best 100$ I could spend at this point to keep my sanity.
Thanks

Keoman

iTrader: (3)

Alright,
So ended up that I toasted my ECM, which I suspected, and that the one i pulled from the JY was toast as well... figures.
So I went and picked up a new one from a local shop and brought it over to the dealership. Car runs great now except the idle problem. Mechanic sprayed carb cleaner around the runners and it jumped the idle pretty bad. Definatly an intake leak somewhere. Gonna go get the car today and tear the intake apart and make sure everything is nice and sealed.
I had the great luck of having a burnt out ECM and an intake leak to make my car run AWESOME at the same time haha...
Thanks for the help everyone.

Keoman

iTrader: (3)

For the love of god someone please tell me what causes a car to do this..
http://www.youtube.com/watch?v=RmEUCWQTzsk

I am unable to pull ECM Codes anymore.

85 ZXX

iTrader: (1)

Seems like the timing advance is not working. swap the ESC with another Camaro to see if thats the problem, possible EST, Did you put your original MemCal in the new ECM box?

ninetyone

iTrader: (2)

did you put a new ecm back in or another used one? how about the "key on test"? CEL SHOULD BLINK ONCE AND TURN SOLID (JUST KEY IN THE ON POSITION ONLY). Your car in the video almost reminded me of having bad fuel injectors.

Keoman

iTrader: (3)

Sorry for the delay, life took over and the car got put aside for a while.

I put in a BRAND NEW ECM. Here is the weird thing. Randomly, the CEL will blink and turn solid or it will blink once very fast and stay completly off. There is a short somewhere, there has to be. Its the only explanation for why things keep working randomly. I have replaced almost every sensor in the top of the engine and the ECM, therefor the short must be located somewhere in the wiring harness (at least thats what I think). I have checked all the injectors, all over 16 Ohms. I assume they are good? The post-previous owner had the injetors all done (replaced) about 8 years agao so it would suprise me. I still have the reciept for the work done.

85,
That may be the case, but do you think it would really have that much affect on just depressing the throttle a TINY bit and the car dying? Hard for me to think so. The thing has a brand new ECM in it. I did swap the MemCal upon receiving the new part.

Honestly I think its got something to do with the wiring harness, which is exactly why I havnt done anything with it since. No Time!

RBob

iTrader: (1)

By the vid it looks like a TPS issue. But without a data log, can't tell for sure.

Look at it this way, what changes as you step on the go-pedal. The TPS% increases, along with the MAF flow rate.

So it could be either one. Does the SES stay on long enough to set a code?

The TPS is a wear item, and a dead spot will do exactly what is shown in the video.

RBob.

ninetyone

iTrader: (2)

the blink test is for a bad memcal

Keoman

iTrader: (3)

I went and got a new TPS on break, I'll install it tonight. I fear that the MAF has gone bad. $$$
I'll use WinALDL and try and get some data also.
Thanks for the help.

ninetyone

iTrader: (2)

you have to wait ten seconds between each key test or it may flash once and turn off instead of stay on.

Keoman

iTrader: (3)

gottcha, thanks

ninetyone

iTrader: (2)

why dont u just unpluf the maf while its running and if nothing changes its prob good still.

Keoman

iTrader: (3)

Unplug it and if nothing changes its still good? shouldn't something change if it looses communication to that sensor?

ninetyone

iTrader: (2)

my fault, i said that backwards. if u unplug it and it should run worse if the maf is still good.lol

85 ZXX

iTrader: (1)

When all else fails and you are tired of F___ing with it, and wasting more money with old or rebuilt Sh*t........


http://www.painlessperformance.com/w...rchField=65104

WASyL

if he has new ECM anyway then cheaper is to get http://cgi.ebay.com/ebaymotors/TPI-M...item1e65cab0c8 form http://www.fuelinjectionconnection.com/ , i got one and all my problems went away, i ordered just the harness and got free all relays and ECS module brand new!

oh and they have MAP version too:
http://cgi.ebay.com/ebaymotors/TPI-S...item20bba57f7a


best regards

Keoman

iTrader: (3)

Thanks everyone. This website holds a special place in my heart...
I took apart the wiring harness the best I could and sanded/redid all the ground connections. Replaced the ground strap on the back of the pass. side head to the firewall and got a new Borg Warner TPS. Crossed my fingers and fired him up. Runs like a charm.
Please, for the love of God, anyone reading this take heed.
DO NOT TRY AND START YOUR ENGINE WITH YOUR MAIN GROUND CABLE UNDONE

85 ZXX

iTrader: (1)

Great to hear that Keo,

Time to focus on another project for your IROC.

Keoman

iTrader: (3)

Well, I may have spoken too soon.

I have been watching the car as I drive it for the last couple months and a new problem has appeared.

To the best of my perception, after the car heats up, it will randomly sputter and almost die. Catch its self, and then run at a high idle (around 1500) and them back off to normal. All this just repeats its self over and over. Some times 2 or 3 times a second, sometimes it will go a minute without doing it. The best I can describe it, its like a "running out of gas" kind of sputter and almost die thing. As i said, the motor shutters and almost dies but "catches" its self and jumps to around 1500 RPM's. (as if the IAC detects the motor dying and opens wide up)

Note: the car runs like a CHARM when its cold. (cold as in after its hasnt been run over night) This problems seems to appear about 15 - 20 minutes of drive time. After things "heat up" if you will.

Items replaced: (brand new)
IAC
TPS
O2 Sensor
ECM
Fuel Filter
Spark Plugs
Spark Wires
Distributor (the whole thing, cap, rotor, everything)


Since this problem occours in this matter, it leads me to think that it may be one of the following:
Wiring harness
VAT's system

I am really looking for some help. All the time spent on maticulouly maintenancing the Roc and you'd think it should at least work somewhat good!

Thank you in advance.

ninetyone

iTrader: (2)

Sounds like you have a bad fuel injector somewhere.

ninetyone

iTrader: (2)

A bad Ignition control module will act up after the engine heats up too.

Keoman

iTrader: (3)

Where is the ICM located? If you dont mind me asking. and how do I go about checking it/ fixing it?

A single bad injector? Just wondering, why would the car run PERFECTLY for 20 minutes - half hour and then start sputtering and almost staling if it had a bad injector?

Keoman

iTrader: (3)

Here's a video I just took.

Symptoms are extreamly random.

I was outside with my ALDL cable and laptop trying to pull data and could not for the life of me get it to work. The last time I successfully pulled data through the cable it was on an XP machine. Not sure if it has to do with windows7 or some part of my car. This is killing me... I JUST WANT TO DRIVE MY CAR!!

http://www.youtube.com/watch?v=eeKC_...O0GJZUwbdl6EMM

Thanks

ninetyone

iTrader: (2)

ICM is on the side of the distributor. You may have to remove cap to see it. Drive to a local Autozone or Advance Auto . Most of them can test it for you. You have to take it off. Dont forget to buy the special sealer that glues it back down and keeps moisture out too.

ninetyone

iTrader: (2)

It may be Windows 7. What cable are u using? What software? I am an I.T. Technician

ninetyone

iTrader: (2)

Do this first. Get out your Multimeter and check to see if u have 5V on the serial data pin on your ALDL connector. This is true for the 7730 ecm anyway.

ninetyone

iTrader: (2)

If u have low voltage on the serial data line then your ecm is bad and you will never connect with your laptop.

Keoman

iTrader: (3)

Quote:

Originally Posted by ninetyone

ICM is on the side of the distributor. You may have to remove cap to see it. Drive to a local Autozone or Advance Auto . Most of them can test it for you. You have to take it off. Dont forget to buy the special sealer that glues it back down and keeps moisture out too.

That is mostly likely not the problem. The Distributor came out after the incident and was replaced by a new one. No parts were swapped or reused from the old distributor. Unless the ICM is on or near the coil.

Quote:

Originally Posted by ninetyone

It may be Windows 7. What cable are u using? What software? I am an I.T. Technician

I am using the USB cable form this website. http://www.aldlcable.com/ The jumper is set to the 10k ohm position.
I am using WinALDL. winaldl.joby.se/ as per recommendation from Rbob.
I am also going to try this driver: http://www.ftdichip.com/Drivers/VCP.htm

Quote:

Originally Posted by ninetyone

Do this first. Get out your Multimeter and check to see if u have 5V on the serial data pin on your ALDL connector. IIRC it should be either pin M or E

I will check PinM for the 5v reading.


I hope the ECM is not bad, as it was replaced after the incident as well. Brand new.

Keoman

iTrader: (3)

Ok, just tried a few things.

Tried plugging in the cable again without any changes. Nothing

Installed x64 drivers from that website. Nothing.

Removed 10k ohm jumper. Nothing

Hooked up multimeter. PinM is jumping between 3 and 4 volts, however never comes close to 5v.

Is this really the problem? I managed to ruin another ECM?