2_point8_boy

OK, Here we go...

Driving down the street, just crusing, nothing too harsh, car cuts out. I pulled into a parking lot, where I tried to get it started.

Cranks, but won't start.
Has spark

Fuel pump primes on key on

Engine cranks and cranks, but only fires once, then dies. It seems like it is firing one cylinder, but that's it. It also seems to be firing
thru the intake. Not like an explosion, but you can see smoke trickling out

It also seems to be cranking like it has no compression at all, kinda weird, but I don't have a milkshake in the pan...yet

things to do:
check fuel pressure
check timing
check compression
check cranking vacuum

At first I was thinking broken timing chain, but I have spark, which means that the distributor is spinning and creating a signal. I plan to take the cap of tomorrow and see if the rotor spins, but of course I have to wait 'til morning.

The wierd thing about it is that I have had no drivability problems before hand. Nothing, nada, zilch, zero, zip.

Right now I am so pissed that the car had to be towed home, that I can't think stright about what might be wrong. Please let me know what else you think I might want to check just in case.

BTW, I also had a bad lifter, but i don't think that that would cause the motor to just die. let me know what you think.

Xophertony

i'm not to engine savy, but it seems to me that if the lifter went south just one valve would stop working. unless it impacted and broke your cam shaft, that would account for it not firing, like for example, valves not opening. but that would make a hell of a racket when it cranked. so we can probably rule that out.

dumb question, is it out of gas?

is the fuel pump making a real roughn chewing on gravel noise, or a nice smooth, brand new blender noise. if it sounds rough it's probably your pump, thats what mine did.

now i am realy treading into unknown (to me) territory. it would still crank if your distributer was fried right? maybe that went out.

well, now that i have posted some stuff, people who know what they are doing can correct me and make additional statements. heck, maybee one of my ideas is actually right. that would be cool. unless its that first idea, that would suck, well good luck

EDIT: re-read your post, has spark, gotcha, couldent be the distributer then, next.

Project: 85 2.8 bird

fuel pumps primes, but what is pressure?
any codes?
what does fuel gauge say? ( might be wrong )
icm may have died also.

2_point8_boy

So far, I havn't done anything diagnostic to the motor. I have no codes what so ever. The fuel pump runs, but I havn't broken out the pressure guage yet. That's for this morning. As for the ICM, I have spark, and it's at perfect intervals, but I don't know if it's at the right time yet. If the ICM actually fried, wouldn't it not have spark at all.

Yes it does have gas, actually just filled up yesterday. That was the first thing I though too, but then i realized that wasn't the problem. If the pump itself would have died, then wouldn't that have some sort of drivability problem before it just quit. I would think it would at least have a slight stumble or something.

like I said, I have had no drivability problems before this, it just died. thanks for the input though.

I'm about to go throw in some laundry and then jump into the car. I'll let you know more as things develop.

2_point8_boy

All right, I have 45 psi worth of Fuel Pressure and I have compression. I get spark, but not at the right time. it's no where near TDC, even with the EST disconnected. I'm thinking a dead ICM, but I don't have anyway to get it tested since AutoZone's tester is busted(reads a new module and the old one exactly the same, and the reading says that it is dead according to the book). They told me that they have been having problems with it recently, so it's not 100% accurate(gee...ya' think?)

If anyone knows of a way to test it through ohm-ing out a couple of pins or something, please let me know.

Jerriko 3.4

That doesn't seem right. If the ICM was dead, you shouldn't get any spark. Only the advance is controlled by the ecm, that's the est. How did you test for spark?

Gumby

Sure it not flooding out???

Lots of problem this year from full tanks and the fuel canister dumping raw fuel into the engine.

Pull the TB hose and look for gas int he intake.

Do a tune up also.

Plugs can just foul like that for no reason. If you ever own a dirt bike you would know this first hand. Some of the older ones had an extra spark plug hole so you could run two plugs, then switch when one failed.

My 2nd gen slowly died from needing plugs before its time and then finally would not run for nothing. Until it got new plugs.

2_point8_boy

ok, here are the latest results:

Compression:
#1: 88 psi in 5 strokes
#2: 132 psi in 5 strokes
#3: 94 psi in 5 strokes
#4: 128 psi in 5 strokes
#5: 130 psi in 5 strokes
#6: 125 psi in 5 strokes

Wet and dry test gave me damn near the same readings, went up only about 3 psi on all but 1 & 3.

Leak-down test results say that I have a bad leak on 1 & 3 into the crankcase(dead rings) and also between the two cylinders(blown gasket). Hell if I know how that happened. If I put a spark plug into either one of the leaking holes, I get about 10 more psi out of the other and get it about 2 cranks sooner.

I replaced the ICM just for kicks. Before I was getting a really crappy spark and it was all over the place(advanced all the way to hell and back usually, or so far retarded that it looked advanced). Now that I have the new ICM in there, I get a beautilful white spark dead on 10* btdc everytime.

Fuel pressure is at 42 psi on prime and drops to about 39 while cranking. Injectors are firing(checked with noid light) and you can smell gas in the intake after cranking.

The only thing I didn't think to check was to see what my cranking vacuum is. I will do that as soon as it stops raining.

Gumby

Well you should never smell gas in the intake. That is the first clue that something is bad. Id start by plugging off the fuel canister lines.

Fuel is injected straight into the cylinders, it should never make its was in to the intake to even smell. Unless your timing was 180 off and it was blowing it up past the valves.

2_point8_boy

That's not true. The fuel is injected basically onto the back of the intake valve, not directly into the cylinder. If the car cranks and cranks and cranks like mine, it never burns the gas and you will smell fuel in the intake.

It has to be something electrical because it jusut all of the sudden happened. If my canister was filling up with fuel and flooding the intake, then I would have noticed that I was getting poor fuel economy and general drivability issues before it just died.

Remember, this just happened...i was driving down the road, after having been driving for 10 minutes already with no problems, and then all of the sudden BAM, nothing at all. Plus, it's not like my intake and cylinders are swimming in fuel. The plugs were a little wet from getting a small shower, but nothing you wouldn't expect from sitting there and cranking the motor with no fire.

The only thing that I havn't replaced in the ignition system in the last 2 months is the actuall pickup coil and distrbutor itself, but if I am getting a perfect spark dead on 10*BTDC, then there is nothing wrong there. That's what has me so stumped, I have fuel, I have a really good clean spark now, and I have air into the intake, there is no reason that this motor shouldn't fire up.

Gumby

Well when dealing with both my past 2nd gen and my 3rd gen, its never what you think it is or what makes sense.

But both has up and quite on me and just needed a full tune up even though it was not time for it. Threw money in every direction but where the porblem was, chasing codes all all kinds of crap.

On the 3rd gen it was right after buying 7-11 gas spent about $150 on nothing but BS as it just wanted a tune up.

These cars do strange things. It is just that so far this year there have been 4-5 people who filled their tank and then started flooding out and it ended up it was sucking fuel in the vac lines.

If everything else is fine and the spark is, grab some 98 cents plugs, $20 wires and a $10 cap n rotor. check your plug index

All I can do is share what I know. If you don't want help I'll stop, your tone in your message is hinting towards that.

CaliCamaroRS

That would be Direct Fuel Injection.

Gumby

You can have all the best timing in the world but bad cap index will make a system very flaky and prone to early failure.

2_point8_boy

Meant nothing at all by what I said. I'm just very grumpy about the car and all the info you've shared so far has been helpful in some way or another. I apoligize if I sounded like I was getting personal.

I actually did go out and look at the canister, right after I posted that, but it turns out that that is not the problem. I unplugged the vacuum line from it and then cranked the motor for about 15 seconds, still nothing.

Please though, keep the sugestions coming, at this point I need all the help I can get.

2_point8_boy

All right, made very little progress in diagnosing the no-start condition.

Now that I have replaced the entire ignition system, minus the pickup coil (which is woring as designed as felt through and ignition spark through my hand). Remind me never to hold onto the coil wire while trying to get a dist. signal...bad idea. Anyway back to the problem at hand.

I put everything back together after replacing all the ignition stuff and it cranks and cranks and cranks until it finally fires, but the "exhaust" presents itself as black smoke exiting through the intake. I also get liquid fuel on the back of the throttle plate and a small puddle at the bottom of the TB. This tells me that I have fuel(obviously) and spark(finding that out really hurt) and that it's at the right time(as found with a timing gun). I also drilled a hole in my old cap at the #1 tower, and with the crank at TDC, it lines up PERFECTLY with the tower and the pickup coil also lines up perfectly.

With all this in mind, it sounds like I have an intake valve or 6 hanging open and all the compression is sending back out the valve into the plenum. From my earlier compression readings, I think it's gonna be the #1 and #3 cylinders.

I have completly removed the evap hoses from the motor(they are all still there, but nothing connects to any vacuum source, so that rules that out as a source for liquid fuel.

I also get NO cranking vacuum what-so-ever. Sometimes it'll ticle the needle and make it go up to about 5 lbs, but that's about it. I just don't know what else to check, it just doesn't make sense.

If it were just a couple of cylinders that are dead, the motor would still fire and run, wouldn't it, albeit pretty crappy, but at least it would move under it's own power.

let me know what else you guys can come up with. Thanks for everything.

Jeff

Vader

Now that all that is completed, what is your base timing?

TJQIROC

iTrader: (1)

Just a stab in the dark but it sounds like the engine is flooded. I don't have a lot of experience troubleshooting 2.8s even though I had a 2.8 Cutlass for years. That one didn't have a distributor. The only thing I can think of is to remove the fuel pump fuse, depressurize the system, crank to sort of dry out the plugs. Give a shot of starter fluid into the throttle body and see if it fires. You may have gotten a bad batch of gas that messed up your injectors and they are leaking badly. An injector leakdown test would show that but I am not sure what is concidered bad.

RB83L69

timing gears

An absolutely textbook description of what a motor does when the pastic teeth get stripped off of the chinesium gear.

Don't touch the distributor. Just change the timing set. If you monkey wuith the dist, you'll just be creating yourself extra work, by screwing stuff up yourself that you'll just have to go back and fix later.

Project: 85 2.8 bird

plastic teeth?

edit: yeah, nylon but I've only known the 4bangers to have them

Doward

Nylon, actually, and if the spark is good and steady, as well as the timing, then that's not your problem.

Double check your firing order. Keep in mind, #1 is on the passanger side - in the front, not the driver's side.

Sounds to me like a timing issue. You ARE using the passenger side as #1, correct?

No ticking, or knocking, right?

Why would it have died in the first place? I think you found that, with the bad ICM. It's merely been complicated... LOL

Double check that you've got #1 in the right place, and actually on TDC of the COMPRESSION stroke. You'll feel the compression build and try to pop your finger out of the hole on the compression stroke - then bring the piston to TDC, and make ABSOLUTELY certain the rotor is pointing STRAIGHT at #1 post. (that's right, zero timing. The motor will fire like that, and then you can adjust the timing).

Firing order is 1-2-3-4-5-6, with

5---6
3---4
1---2

(front of engine)

Good luck.

2_point8_boy

positive that the timing is fine. At first I thought that I may have popped a timing chain, but the rotor spins in perfect tune with the crank, just like a new chain, no slack or anything. Then I thought that it had just jumped a tooth or 2, but i found that that wasn't the problem becuase the rotor points directly at the number 1 dist. tower on the cap. I figured that out by drilling holes in my old dist and turning the motor to #1 TDC.

The weird thing about it is that I don't get ANY cranking vacuum at all. That leads me to think that the chain is broken and something is hanging open, but if the dist spins in perfect time with the crank, then the cam is spinning, which means that the chain is intact.

The only thing that I can think of at this point is that one or more of the intake valves in hanging open, whether by busted spring or actually cracked or something and then when the cylinder fires, it spits out the intake since it's open. On my next day off i have to pull the rocker covers to find out.

The thing that kinda shoots that theory in the foot is that usually before something that major happens, you have drivability issues like stumbles, stalling, hard starting, etc. I had none of that. i was just crusing down the road and then it cut out with no warning.

The base timing is set dead on at 10* BTDC, right on the money for where it's supposed to be. It's also exactly the same every damn time. No scatter what-so-ever. Firing order has been looked at 20+ times, it's really pissing me off.

i have also tried cranking with the throttle wide open, which during cranking puts the computer into clear flood mode. Didn't change my scenario at all.

I just don't know what else to try. Keep the ideas coming guys. Any and all help is appreciated.

rjmcgee

I would still pull the timing chain cover and inspect it. You can also hook up your timing light and have some one turn the engine over and check it. Sounds like what RB said, and it is hard to argue with the old timers and their experiance.

CaliCamaroRS

Have you done any injector testing?? Balance test, coil test, or Ohm check? Like I've said before, on a batch fire system I've seen ONE single shorted injector prevent an engine from starting.

Also, where are you hooking up your vacuum gauge? To manifold vacuum or ported vacuum?

Vader

I was trying to get him to think through that one. Reading the previous parts of the thread, he had already moved the distributor all over the place, so the timimg isn't relevant any more. Initially, it WAS way off, which screams "timing chain", as you suggest.

Backfiring, ignition timing all over, flooding, poor compression, low vacuum - that all indicated valve timing off. The sudden change is pretty typical of the cam sprocket taking a dump. The age/mileage is another clue.

If he keeps it up, he'll have a new ECM, new distributor, new fuel pump, new injectors, new spark plugs, new vacuum lines, new starter and battery, and who knows what else. Then he'll check the valve timing. At least he'll have a lot of reliable new parts.

2_point8_boy

I replaced the ICM before I started messing with the dist. he only thing I did before replacing the ICM is making sure that the rotor spun with the crank. I then immediatly replaced the cap and rotor, without changing the base timing, disconnected the EST and checked my timing. Before any messing around with the dist, it was jumping all over. I then carefully removed the old ICM, finally got it tested(bad BTW) and replaced it, all the while, doing my best not to mess with the position of the dist, that way I knew I was getting accurate results. Aftrer replacing the ICM, the timing was dead on accurate everytime. From that point I tried messing with it, just to see if it would start at a different timing spec...no luck. With a rotor that points directly at #1 when the cylinder is at TDC, I highly doubt that the cam has jumped a tooth, it it did, then the dist would have jumped exactly the same in the opposite direction that the chain did, and come on, what are the possibilities of that happening???

As for checking the injectors, I have checked resistance on all of them, every single on is 15.9 ohms, I was kind of suprised to see that they were all exacly the same, especially givcen their age, but that's what it was.

I tried to pull cranking vacuum from the manifold source on the back of the plenum where the heater controls and cruise get thier vacuum from, I simply disonnected the lines at the nipple and popped on my vacuum guage.

I do agree with the theory of valve timing being screwed up, but the whole distributor thing really doesn't help that theory stand up. If someone can explain this, then i will be all for ripping the front of my motor apart to replace a timing chain, but I really don't want to if the rotor spins with the crank WITH NO SLACK and points to the right tower at precisly the right time. That clues me in to the fact that the timing set c an't be all that badly worn, but please feel free to let me know how you would explain it.

I know that I sound like I'm being a complete jerk off about this, but I've been over this stuff a million times with guys from the shop I work at and the one behind me, they all said the same thing, but when they heard what I said about the tests that I have done, they are just as confused as me.

Please, keep the ideas comming and share any knowlede you have on the subject. Thanks again

85firebird

> Backfiring, ignition timing all over, flooding, poor compression, low vacuum - that all indicated valve timing off.

Good point. The cam is driven by the crank, and the distributor is driven by the cam. Timing chain skips throwing off all valve timing and therefore spark timing. You then adjust distributor so that spark timing is correct relative to the crankshaft, but the valve timing is still off relative to the crankshaft.... and now the valve timing is off relative to the spark timing!

Note that there may be more than one notch in the harmonic balancer. If there is, the biggest one is the good one. This can be a problem if you're not careful when finding TDC on cylinder #1. I once had the timing all set up according to this other notch, the car wouldn't start, and it confused the hell out of me.

KED85

The vehicle was running before it died.
The chain is in fair enough shape to not be the cause.
It's an electrical gremlin
Check junction blocks of the wires.
ALSO check the engine grounds
CHECK alternator! PULL OFF & bench test it
Battery have fresh charge?
IF the car was in past accicent check wiring at that front corner for possible damage.
It's flaky wiring that has killed this ride.

Blue1989RS

Make sure you tell me what you find! I just posted a thread, check it. I also have the same intake "back-fire". It happened once before and it was due to some sticky lifters. They were all the way pumped up so the valves weren't seating. Sounds like I'm right there with 2.8boy.....

KED85

As an FYI,
my 1985 S-10 Blazer 2.8 with 211,500 miles on it, fired & ran "well" with each cylinder only showing 50 pounds of compression.
If something is "sticking" open, it'll show zero compression & then engine won't ignite.

This not running problem could also be the ground wire from battery to chassis is poor.
When Corvettes first made on assembly line (1953 now), the first cars were pushed off.
Engineers, first time workers of fiberglass to metal frame, did not include enough grounds for engine ignition. Yes that problem was solved quickly, even back then.

2_point8_boy

I do have multiple notches on my crank, but the one for TDC is marked with white paint, I did that when I first got the car because you could hardly tell which one was the right one.

I don't know about everyone else's car, but I have the negative battery wire attatched directly to the motor, bolted on by the AIR pump, it's been like that ever since I bought the car and has run fine. I will check that since I did overlook it, but it seems to me that since I crank very well and have a really good spark, it's not a grounding problem.

Tomorro I will be tearing off the valve covers to check my springs. I'll know more tomorrow night...wish me luck

Blue1989RS

So whats the deally yo? Have you tried to measure the slop in you timing chain? Grab the crank pulley and spin it over until the timing mark is about 10 on the dial. The spin the crank over the other way until you feel the "clunk". Divide the degrees you see by 2 and thats how much valve timing you have. Mine is 6 degrees between "clunks" so my valves are about 3 degrees off of crank timing. I've got nothing to worry about. But I also checked another 2.8 block that I have and it measured 20 degrees of slop! If your's is way off, it could be why you don't have any cranking vacuum...

2_point8_boy

my rotor spins in perfect time with my crank, I can't feel any slop in there at all, that was one of the first things I checked. Thank you though.

Blue1989RS

ITS ALIVE! Seems like the problem with the no start was the pickup coil. I still have to time it but other than than it works like a champ!

KED85

Aged pick up coil wires do like to drop off their connections.
No one bothers to replace that item, due to one needs disassemble the distributor for pick up coil replacement.
Stupid cheap $10 parts cause lots of problems.
Send that "fix" out LA way for 2_point8_boy.
He has a day and a half of no rain to solve his problem on his ride!
Locally Weds afternoon/evenign is to be "Get out the buckets" type of rainfall.

biff85ta

You still need a head gasket. If putting a spark plug in one hole increased the compression in the other the head gasket is blown and even if it is not putting water into the oil just yet it will.

KED85

IF ya need a set of heads, my available rebuilt with several new guides 2.8 set is local to ya. Wish I had those head gaskets for ya, too. Let me search, I just may....

KED85

I have a set of rebuilt 2.8 MPFI heads (has several new guides, too) & MAYBE 2.8 head gaskets.

KED85

Found the new 2.8 head gaskets.
Hope you're doing OK in the rain.

2_point8_boy

First off, let me start by apologizing to all of those who said that it was a valve timing problem that I shot down.

The problem actually did come out to be the timing chain. The driver's side fo the tensioner broke off and got stuck between the crank gear and the chain. When the crank was able to pick up the teeth, the rotor moved eactly with the crank, but when trying to turn the motor by hand, I couldn't get it past #2 or #5 compression strokes...even with no plugs, like it was building compression, so i decided to dig in.

Last night, in REALLY hard rain(Karl can vouch for that one), I pulled the front of my motor apart and found the problem. I'll post pics for you guys.

I replaced the chain, gears and tensioner and the car runs now, but I now have an ignition misfire, you can feel it when you drive. I think I fried a couple of wires with all the cranking with no fire.

I also found that when the motor came around to the teeth that were now permanently joined to a 3 inch peice of metal, it had the rotor right at a pickup point on the coil and was shaking it enough to get it to fire, but at the "wrong" time. Co-winki-dink??? weird I say. anyway, pics of the carnage commin' up...

2_point8_boy

My bad...screwed up that one. please disregard this post...see next post

2_point8_boy

dammit...still won't work. looks like I'm just gonna have to build a page for them tomorrow. you can see then.

KED85

Last night, in REALLY hard rain(Karl can vouch for that one), I pulled the front of my motor apart

THAT IS DEDICATION TO THE PROJECT!
As it really rained very heavy for quite a bit.

Now people understand why it's so important to replace also the TENSIONER when the timing chain is replaced.

On my Firebird 3.4, I'm going back in to replace my tensionser and install a balancer snout sleeve, due to my lack of doing so when I first assembled the engine.

Good to hear how well your mission is proceeding along.
NO rain for several days yet it's chilly.....
BETTER to hear a solution is in sight.

Get engine running, open car hood in mostly total darkness.
You'll see any shorts under the hood, instantly.
Better to know ya not needing a head swap mission.
Looks like I refound all my MPFI head & gasket stuff for nothing.

88_4_1499

Yippee! I've been using this site for well over a year and a half - since I got my '88 2.8 Firebird (138K miles).

I thought it was time to push it off a cliff until I came across this and this other thread

https://www.thirdgen.org/techbb2/sho...hreadid=223614

Same symptoms: topped off the gas; drove about 5 miles; engines lurched in low RPM; parked all day; drove 2 more miles, same lurching; parked for 10 minutes; drove 2 miles while lurching. Then, silently rolls to a stop. Fortunately, I was in parking lot.

It sat there for four days while I did my homework. Thanks to KED85 for pointing me to the $15 ignition coil replacement. I'll follow that up with a new distributor cap and pick up coil.

Plugs, cables, AIC, tuneup all within 12,000 miles ago.

1988 Firebird 2.8| All stock

KED85

A crappy coil can really ruin your day.
My Firebird died on my Wife, pregnant at time, in the rain, at intersection.
Luckily, I was close by to "rescue".
I learned by throwing everything under hood at it.
All buddies said, it's got spark......
Spark got to be lightening bolt White to be an effective spark for these MPFI engines. Only way spark seems to quickly return is by new coil.
Yeah rebuilding the distributor does and WILL give a great return on investment for your engine.
Could also add a gallon or two of gas milage increase.
Wish I had me as a coach when my coil went back in 2000!
Glad I could toss ya a good cheap solid solution

2_point8_boy

Please forgive on the size of these images:

Tensioner:


Crank gear pics

2_point8_boy

I am still having a slight problem with surging...three days later, but it runs and doesn't leak anything. Also funny how adjusting the valves gets rid of an annoying tick that I've had forever.

I was thinking that the surging problem might be from the computer having to relearn all of the fuel trim data that it's had for over 2 years now. This was the longest I have ever had the battery off for(2 days) so I think it just forgot everything and is relearning because it is getting better and better the more I drive it. Might also be a problem with a misadjusted TPS...don't know yet.

The reason I had to get this thing going in the middle of the night, in the rain was because I was out buying the parts for the Camaro when the Air Flow meter on my fiance's '83 Volvo went bad...also leaving me stranded in the rain. i finally narrowed it down to the meter and was able to unplug it and get the car home...it runs, but very very crappy. It was $180 and I have to order it, so I'm waiting on that for right now.

Also, driving the car today and I sem to have melted the oxidation bed of my cat into a tiny ball, it rattles around like rocks in a coffee can. pretty sure it's fully gutted at this point.

At least it runs. I think that I am going to get my upcoming move out of the way an start on a 3.4 scheduled for compleation at the end of summer. Anyways, thanks for all the help guys, and again, apologizes to those of you who were right and I shot down. Later.

Jeff