Mathius

Ok, I'm just about ready to giveup trying to figure out why my 3.1 camaro won't stay running. I've put a fuel pressure gauge to it and it put out above 40 psi, I checked and it isn't throwing any codes. It runs, but it dies after a while and you can't keep it running without hitting the gas (seems like not getting fuel?) Sometimes hard to start too.

I disconnected the MAP sensor, didn't help, changed the plugs, wires, cap 'n rotor, o2sensor. Fuel injectors have been cleaned and flow tested by Cruzin performance. Coil and alternator are brand new, and battery's still under warranty.

2 things I haven't done anything with. Someone told me it could be a bad catylatic converter and backpressure builds up after the engine warms, causing the engine to die. This brings me to my question, but I'll get into that in a minute.

THe other thing I was told was to check my fuel lines for leaks, that air could cause problems even if it was just a small leak. I changed the fuel filter, but otherwise have done nothing with the lines.

Tonight I went out to try and start it just to let the battery charge a bit and it fired up, which is good, but I noticed something. It was cold out, so I could easily see smoke coming out the tail pipe. Funny thing is, it was only coming out one tail pipe. I put my hand to the other tail pipe and could feel air coming out, but definately not as strong as the driver's side outlet. I have a flowmaster style substitute installed by Tuffy's a few years back. It has a single muffler with 2 tails coming out like the stock exhaust. No tailpipes. (tips)

Could this be an indication of poor exhaust flow, and possibly point to my problem or am I just being hopeful?

I'm just about ready to start giving up and hacking this thing up for parts, or selling it outright as a parts car. I'm really frustrated with it.

Mathius

Doward

Sounds like it. Do this - remove the oxygen sensor, and see if that gets any better. If so, then yes, your cat is clogged

Another thing, you should usually smell 'rotten eggs' (sulfur) when the cat is shot.

kretos

if you have to keep pumping it to keep it going, i'd say fuel filter or clogged cat

ljnowell

does it make a horrible sound when you rev it, kinda like its breathing back through the throttle body? Thats the sound my 2.8 made when the cat was plugged up. I can recognize that sound from a 100 ft away now. I went through the same ordeal as you, and when I found out it was just the cat I was pissed.

Gumby

3rd gens have fake duals. more air out of one pipe then the other is not uncommon.

You live in a smog check free zone right???

CaliCamaroRS

If the converter was plugged, it wouldn't just act up hot. It would act up all the time.

Also, typically when a cat is plugged, it's only noticable under load. Many cars with plugged cats will rev fine in neutral, but once you put it in gear and under load the engine will struggle to spin and it will usually backfire as well. If you want to be sure, you can hook up a pressure gauge at the O2 sensor bung and measure your backpressure.

Check your fuel pressure regulator for fuel leaking into the vacuum line. Have you rebuilt the disrtibutor recently?

Mathius

No, just had it checked it feb, passed the smog test. I hope I don't sound like an ***, but I stated that I have two tails coming off the single muffler, I know I have fake duals. Still seems like there'd be a clog somewhere, even if it's the muffler to have such uneven pressure.

It seems totally random, but usually the car will start up fine but idle rough. After it dies, it usually won't start until it sits for a while.

I haven't rebuilt my distributor, but like I stated, damn near everything else has been fixed/replaced in the ignition system.

Mathius

Mathius

Haven't really listened to it while rev'ing it, the car hasn't been on the road much with its problem. It idles really really rough though.

Mathius

camaro_junkie

Hmmm. This is a tough one. When my cat was clogged (it was really clogged) it ran fine at idle and started fine, it just had absolutely no power. I'd definitely take the O2 sensor out and see if that helps. Don't replace anything until you try that.

Otherwise... anyone else think it might be a dying fuel pump. When my fuel pump died, it just died, but I've heard of others who had one that slowly died.

Project: 85 2.8 bird

you said the fuel pressure is about 40. Is that w/just the key in the igntion? What is pressure while cranking, and whenit does kick over.

My Blazer had a fp go out onit. It had perfect fp w/just priming it, but it coiuldn't hold pressure enough to start & run.

Gumby

The exhaust will flow like electricity. Its takes the path of least resistance. Maybe one side is more dirty but even if you totally plugged of one pipe, it should still flow fine.

redraif

it seems like a dumb question, but what is your timing? Is it really hard to set.

Mine was really hard to set and it would jump from 5 to 20 when we were trying to set it. Idle was irratic. Car would even stall out. Just very irratic and hard to zero in. We rebuilt the dist, but were still having problems. Then Joe thought about spark scatter. If there is too much endplay in the distrubutor it will move around and could affect your timing. We used moroso shimms and set it to factory specs...threw about 12 degrees on it and it ran like a new car! Just a thought!

Also your idle air control valve. Whats its condition?

Mathius

Well, it doesn't seem to be the catylatic converter. I pulled the o2 sensor, and took it for a spin. Drove it about a half hour before it stalled when I stopped to turn around. Then it stalled 2 more times at stops and twice more around the corners, until finally stalling completely at the end of my street. I had to push it into the parking lot of the apartment buildings down the street. Anything below 2000 rpms and it stalled until finally it wouldn't start again the last time.

I'll check the timing as Shannon suggested, but if it isn't that, then I'm done with this car. I have too many cars, and I don't want to mess with it. If it is the fuel pump, I don't wanna go through the trouble of fudging with it. I loved driving it when I first got it, but ever since I stripped it down for paint and then had to move instead of getting to finish it, I just wanna get rid of it and start a new project. So this one will probably end up parts.

Thanks for your help guys.

Mathius

305q_ta86

iTrader: (1)

My v6 did the same thing. problem is, it had no cat. Then I found a vacuum hose that was part of the EGR setup that had been partly melted and clogged, so I replaced it and it got a lot better.

Gumby

I found vac hoses that looked fine but where so dry rotted, that with the car running. they sucked them selfs shut.

a fuel pump isn't hard to change if you do it the white trash way. Which I endorse wholly. Chop a holes int he back seat area, rather then dropping the rear end.

camaro_junkie

It's also not that hard to do if you do it the completely unsafe way. Back the car up onto some ramps, disconnect the rear suspension from the frame, and then jack the frame up into the air.

Mathius

All vaccum hoses are brand new replaced last summer with silicone hoses.

I don't wanna spend the money on a new fuel pump, and it's hard enough trying to work on my car in an apartment, whether I cut it out or not. I'd have to run an extension cord all the way around the building to use a cutting tool.

Mathius

Gumby

The few time I had problems with the car and chasing trouble codes and what not never seamed to help. One timed i did the same and changed everything under the sun But a full tune up fixed it every time. Even though it was not time for one. New cap,rotor,plugs n wires seam to be the fix all. Even if its not time.

KED85

I think it's your coil that is aged.
As engine heats up, the innards "expand" weakening spark.
I know this problem due to
One time bought an Accel coil at swap meet.
HEY THEY ALL LOOK SAME, IT'LL FIT MY CORVETTE! Shiny chrome circle one, real pretty.
Initial driving gave good results.
As I drove, engine warmed, performance got real poor.
Corvette performance real poor as I was on a date with real cute girl too.
Switched cars, left Corvette, went back out.

Next day I phone Accel.
They asked me what number on the Accel coil I bought.
I was told I purchased a CHRYSLER RACING COIL!!!
I was told that their "racing coils" shot out mucho volts, BUT only for "short durations" (of a 1/4 mile nature!).
I was told constant road usage will give me exactly what was happening due to windings separate (heat needs room to expand) during the road usage & the energy signal constitantly weakend over the "road usage drive time".
Exactly my situation.
Stuck on correct Accel coil (another swap meet find! #140001) and no probelms for over 6 plus years. And it's a used Accel coil, too!

I think it's your coil has a slight crack in it!
Expands as car heats up. Ths engien weakens & eventually dies.
Try replacing it & see what happens!

Accel is about $30-ish. I mounted mine on firewall.
Follow the yellow Accel plug wires! to see coil on firewall.

On my brand new 1975 Vega (first year of the CCs) the NEW CC SMELLED OF ROTTEN EGGS SO BAD! IT WAS FOUL!!!!
My 85 Firebird CC, become chunks, as CC hit floor due to decomposing of innards. NO STINK, just loss of highway power & performance.
My experience of CCs.

I say beat up original factory coil.
Look at factory issued location. Sure fired place to cook an egg every day of car usage!