[justbrad]

Hello, I bought my Camaro new in 1994 and have had very good luck with it until this past Sunday. My son backed it out of the driveway and when he put it in drive, it quit running and I haven't been able to start it since. The first thing I did was to check the oil and it smelled strongly of gasoline. The engine turns over, and sounds like it wants to start but won't.

I have replaced the following items with new parts: Spark plugs, SP cables, Ign. coils (all 3), O2 sensors (the 2 on the exh. manifolds), air filter, fuel filter, and fuel pump. I have also changed the oil and the oil filter.

I'm kind of stuck now on how to proceed, (my limited imagination is at an end at the moment) whats the next step, shy of towing it to a real mechanic. Any and all suggestions will be greatly appreciated.

Thanks Brad

 

[justbrad]

Kustomwerker,

I tried one plug and it sparked. However, my battery has decided that it is getting old and tired of trying to start the engine. I've got it hooked up to a charger now and will try the rest of the plugs later this afternoon. I think this battery is about 4 years old so I'll probably put a new one in this afternoon also, depending upon how well it holds a charge.

Thank you
Brad

 

[justbrad]

Ok, back to it. The spark plugs have spark. My battery seems to be holding its charge for the time being. When the engine is turning over, it sounds and smells like its flooded. Could this be caused by the fuel pressure regulator malfunctioning? Delivering to much fuel to the injectors.

Thanks

 

[justbrad]

Thank you Everett,

The spark plugs were wet.

I'll switch out the temp sensor this afternoon.

I also ordered a FPR diaphragm kit that should be in this afternoon.

I'm heading out now to pull all the plugs and let cylinders and plugs dry out for a couple hours. I'll change the oil & filter again right after it fires up and runs for a few seconds (or minutes).

I bought the Haynes manual back in '95-'96 when I first saw it at AutoZone it's been a real life saver. I think I've read it from cover to cover about 3 times. And now a fourth time during this problem. Unluckily it only devotes about 1 paragraph to the FPR for a 3.4L.

edit: I read on this forum somewhere about the same problems and it turned out to be the FPR was the culprit.

Thanks for your input, it is really appreciated.
Brad

 

[justbrad]

Just an update. still not starting.

Checked the temp. sensor and it came close to the resistance that Haynes noted so I didn't replace it (Can't check it with a hot engine though).

I tried checking for trouble codes using the jumper method on the ALDL between the Diagnostic TEST terminal and ground. The SES light lite-up but never flashed.

Question 1: Does this have to do with disconnecting the neg. battery terminal and erasing the ECM memory or is it a sign of a defective ECM?

The FPR diaphram kit install went smoothly however no different results.

With the cash I've thrown at this car so far this week it should be running better than it has in years.

Question 2: The spark appeared to be orange/yellow not blue. I bought AC Delco spark plugs and they are gapped at the recommended 0.045". Since I'm probably gonna have to remove the plugs this evening again and let the cylinders dry out would it be a good idea to replace these plugs and with what kind due you folks recommend.

edit: Question 3: Forgot this one, would a clogged Catalytic Converter or the timing chain be a culprit to not starting. (Car has 145k miles.)
Thanks Again
Brad

 

[justbrad]

Thanks again Everett,

I thought the SES light should have flashed.

I talked to a friend earlier this evening and his first thought was the timing chain. So, tomorrow morning he's heading over and we're gonna pull the front of the engine off and replace it, I've been dreading this, and have refused to talk about it. I watched my dad replace timing chains a few times but have never attempted it myself. SWMBO reminded me at dinner that we used to own a Ford Escort that threw timing belts every 50k miles and had the same symptoms as the Camaro does now (must be that "old age" thing, I just can't remember).

So anyways that is the next step (I think).

I can't wait to get my Camaro out of the garage so I can get back to my favorite hobby, brewing beer. My kegerator is starting to run a little low.

Thanks
Brad

 

[justbrad]

Hi Guys (kustomwerker & Everett),

Just to let you know that I haven't given up. I've got the front of the engine off and the T-chain exposed (new chain & sprockets due tomorrow, Monday, at 12:30 pm) my arms were really tired last night, I could only lift a few pints. My initial thoughts are: the timing chain has a lot of slack in it, however, it hasn't, visually, skipped any teeth. However, both sprockets look worn. I'll know how loose it was when I put the new chain and sprockets on tomorrow afternoon.

One thought, on the side, I didn't have to remove the water pump from the timing chain cover to remove the timing chain cover. This is going to be another gasket that I have to replace. Haynes steered me a little off. Also, they (Haynes) recommened that I remove the oil pan ( I didn't).

I didn't change out the MAP sensor because it is vacuum supported and Everett is right. No vacuum until the engine is running so... I'll find out tomorrow evening if this works.

BTW, I do get exhaust fumes out of the tail pipe (strongly). So I have to assume that my CAT is not clogged to the point of not starting.

Thanks again guys your thoughts and comments are greatly appreciated and have kept me motivated to keep going.

(edit: I talked with my neighbor today and he has a cylinder compression gauge. If it doesn't start Monday evening I'll let you know what the compression psi is with this no start.)

Brad

 

[justbrad]

Hi Guys,

Thanks for the replies.

I just got the old gasket mat'l removed from the covers and engine block. I will probably be putting the T-chain back on tomorrow. The old chain had about 1/2" of slack with the other side tight. The water pump gasket came in the gasket kit, yeah, something went my way. Removing the water pump was not a big problem really, so I'm glad I followed the Haynes advise. They didn't steer me wrong.

I'll check out the MAP sensor next, one way or the other, this car will run again. I'll also check out the fuel line pressure and make sure it is not loosing pressure.

I'll check back in when I get everything re-assembled.

Thanks again,
Brad

 

[justbrad]

I got it all back together last night. Believe it or not, I'm really having fun with this. However, it would really be frustrating if this was my primary car.

I'll (hopefully) refill the oil and anti-freeze this afternoon and will post back with the results. I'll check the ECM resistance while filling the oil.

The SES not flashing is really bugging me. I checked online and found new ECM's for around $100 (not-programmed). What am I looking at for programming. I haven't checked online or locally yet. If I remove the ECM, can I take it somewhere locally and have a diag ran? Also, the battery is disconnected right now so the ECM should reset when I hook the battery back up. I've checked every fuse, that I know of, and none are blown.

What is the best way to check the TPS voltage without destroying the integrity of the wires (I'm thinking some sewing pins).

I plan to re-read this whole post this afternoon also to see if I missed anything you folks have said.

Thanks again, I'll post back in a few hours and let you know about the outcome.
Brad

 

[justbrad]

The good news is that I have no coolant or oil leaks. The bad news is it did not start. I didn't crank it very long, however, the engine sounded like it was becoming more serious about starting.

It's been 45 mins. since I tried to start and there is still pressure in the fuel lines, don't know how much. I'm gonna run out in a bit and pick up a fuel line pressure gauge. I probably should have done this first. Anyhow.

From what I've been able to find out it is OBD I. I was expecting the code 12 but get no SES flashes at all, the light just stays on. I'll be really careful to ground myself and eliminate any static if I dive into it (the ECM). Autozone has a OBD1 scanner for $25, however, the fellow there said I'd get the same info with the jumper. I might just buy it and give it a try, what's another $25 (what am I saying, that's about the cost of a 10 gal. batch of ale I want to brew).

From what I've read the e-prom is soldered. I'll check whats available locally with the ECM while I'm out.

Right now I don't have the air filter hooked up, but I replaced it when this whole mess started, no major clogs, just one autumn leaf.

I think the next step is to re-read Haynes manual sections about Injectors and the ECM.

Thanks again for all of the valuable comments.
Brad

 

[justbrad]

Okay, picked up a fuel line pressure gauge, should have done this earlier. Hooked it up and turned the key to the on position. The fuel pump ran and the pressure went to 47 psi then started to drop and was down to 42 psi in less than a minute and kept falling.

kustomwerker wrote: "if its a leaky inj, or fpr, the fuel pressure guage will peak when you turn on the key, and then drop...if everything`s good, it should hold pressure at the rail indefinately..."

So, (this is like finding lost shoes, they are always in the last place you look) I'm gonna focus in on the injectors.

(Autozone has pre-programmed ECM's for $125 BTW).

What is the best way to find out which one(s) is/are open. I'm thinking that if I pull 1 spark plug at a time I will get a pressure drop when i remove the plug that is associated with the leaky injector. Or do I need to read the resistance of each inj. Or do I use a screwdriver and listen while someone cranks the engine (really don't want to do this). If they are all open I'm thinking ECM.

Replacing the T-chain got me over the "I've never done that" hump. I'm not at all worried about replacing injectors now.

Thanks again!
Brad

 

[justbrad]

Thanks kustomwerker,

I'll do the noid lite test tomorrow. I believe that the ign. coils batch fire, not sure about the injectors though.

Thank you,
Brad

 

[justbrad]

Everett,

No timing light. (I'm short on diagnostic tools still)
About half the times that I've tried to start it I have been holding the pedal to the floor, haven't notice any changes in the way it cranks.
The no code 12 is really bugging me also. Haynes says to take it to a qualified dealer (Don't think that is gonna happen). Autozone said 2 day delivery on a new ECM. I think I'll go order it so it is here by Saturday (yah, it's bugging me that much).
In the mean time I'll pick up a noid lite and check the TPS, inj. resistance, and check out the crank & cam sensors.

edit: I have to put this car on hold for a few days. Something else came up that I have to take care of first. I'll check back in when I get back and before I try the things I wanted to try today.

Thank you all for the responses.
Brad

 

[justbrad]

Finally got back and have an update.

1. Injector resistances (all 6) were 12.1-12.3 ohms (Haynes rec. 11-14 ohms). I had no luck finding noid lites locally BTW. So, I assume inj's are okay (thank heavens).
2. The TPS checked out in the correct voltage range per Haynes.
3. The MAP checked out also.
4. Camshaft sensor responded as expected per Haynes.
5. I ordered a new ECM. It should be in on Wednesday afternoon.

That's pretty much it for now. I hope to run a compression test this afternoon and plug the injectors back in (BTW, the injectors are really tough to get to in this car).
Brad

 

[justbrad]

Wow, that is a PITA...

I did a search and found the odd '94 OBD 1.5 weard, what were they thinking stuff. (Everett, your link took me to a pic of a palm tree.)

Well, one way or another, I'll find out tomorrow if it is the ECM is the problem. I'll try and run a compression test tonight (if I get a chance) as you described and check the fuel pressure also.

Thanks
Brad

 

[justbrad]

Sorry, had the book right here when I posted last and forgot it.

Haynes manual states only "OBD". It does refer to "OBD II system, used on 1995 and 1996 models".

I have not seen any specific reference to "OBD I" in the manual I have. And it suggests taking the car to a qualified dealer/shop for diagnosis. It does give the trouble codes though.

No problem with the palm tree. I googled "OBD 1.5" and found lot of references. Some of the links that the ALDL jumper from gnd to diag. (A to B) doesn't work on late 94 and 95 GM models. However, I bought this car on March 17 1994 (St. Patricks day). Is this a late 94?

Thanks
Brad

 

[justbrad]

Well, I'm back with the latest updates.

Mfg'd on Feb, 1994.

New ECM installed and "flashed" per Autozone. Engine cranks but still no start. The new ECM also did not make the SES light flash. I've found a few tid-bits of info on this but nothing conclusive yet.

For my next trick I think I'll measure the compression and maybe try new crankshaft sensors (haynes doesn't give any diag to check them out).

BTW, the fuel pressure at the rail dropped from 48 to 22 psi in 75 mins. (0.34 psi/min) fairly consistantly.

Thanks again for your input.
Brad

 

[justbrad]

Thank you Everett,

Just to let you know, I haven't given up yet, but am pretty discouraged right now. I pushed the car out of the garage because I have to replace the oil in my other 2 cars. I'll pick up a timing light as soon as I can and I'll take a good look at the engine in the dark (that's a suggestion). I probably won't do anything this weekend but hope to get back on it next week.

Again, thanks for all the help. It is greatly appreciated.
Brad

 

[justbrad]

Kustomwerker,

thanks. I'll find a noid lite. This car has more sentimental value to it than any other vehicle I've owned (and there have been a lot).

I keep focusing on the way it quit running (maybe a mistake), but it just died in the middle of the road, like something broke. And what is a dis module?

Thanks
Brad

 

[justbrad]

Conclusion...

I'm not bringing up an old post just for the heck of it, I just hate leaving things unfinished.

I finally had this car towed to a mechanic (about 2 months ago). And they were able to fix it. Yippee! I picked it up this afternoon. It turned out to be the ignition module was bad and caused miss firing (I wish I would have changed it out when I replaced the ign. coils at the beginning). Anyhow, the Camaro runs like new, it should after everything that was replaced on it.

Thank you to all who helped out.
Brad