I am almost ready to give up

[DeMasi1990]

Hey Guys,


I am sure you ALL know what its like to not be able to Drive your firebird/camaro for a long period of time, Due to restoration,expensive repairs accidents etc. Ive been without my car for quite some time and its killin me... My last post was about the car not running right..I still have the problem. She Shakes back and fourth like theres 2 people on each side rocking the car ( not violently) but you can see it. I cant keep the car running for long because it smells like exhaust BAD, and I mean real bad..I brought the car to my mechanic, hes had the car for 2 weeks.. everything Checks out, EVERYTHING...one last test he has to do is a compression Test. why I have no idea, because its not burning oil and its smoking at all... O2 sensor has been Replaced, the aftermarket C-jet Chip has been removed " it kept throwing a code for the EST, and on the 1990 models the turned port is Speed Density and the EST or ESC " I think its EST" is built into the computer and not on the firewall. The car throws NO CODES at all...

Sometimes Ill start it up, it will run smooth no stink nothing. Ill drive it around the block, and the harder you hit the gas pedal the more torque you feel. Its peppy and LOADED with POWER!!.. But then sometimes It will start up, and give the shakes and stink, But all the power will be there UNTILL it Warms Up.. after it warms up, all power is lost.. It feels like a tired V8, even tho its rebuilt.

When I bought this car, I bought it not running, It had a Bad fuel Injector that shut down the engine as soon as you started it. It would run for 30 seconds and die. We replaced the fuel pump, and with a scan took my mechanic found the bad injector. he told me that the injector was grounded or something to that effect and it was interfering with the whole row of injectors. Changed it the car was as good as new... I just had to deal with the Service engine soon light till we discovered the aftermarket piggy back chip was bad. This was a different Mechanic, the mechanic now running all these tests tell me everything checks out with the injectors, But I have a feeling my whole Problem is the injectors.. If anyone has any information that could help me it would be greatly apreciated... By the way, when the mechanic took the plugs out they were saturated with unburned gas

New Fuel pump and filter
New fuel Pressure Regulator
New spark plugs wires distributor cap and rotor and COIL

Only thing Original on that engine is 7 fuel injectors and the distributor it self...Either its not producing correct spark Or injectors are dumping too much fuel...I can narrow it down, But I AM SOOO LOST

1990 trans am T.P.I Speed density 5 speed manual.. Original 305 Bored 0.30 over making it a 309 Oem computer MSD Wires and Coil. thats the engine in a nutshell

[five7kid]

Not sure how much it will help, but a few points:

It is possible to have bad compression without using oil or smoking. A leaking valve will do that, and won't set a code.

The ignition system has almost no feedback to the computer. You can have a bad module, bad spark plug, bad coil, bad rotor, or bad cap, and none of them will set a code.

It's possible to get bad new parts.

Injectors can check out electrically and still be bad. The only way to know for sure is to have a competent, properly-equipped shop do flow and pattern tests on each one.

It is possible for the computer to have problems and not be able to tell you it's having problems. It's possible for a bad electrical component to take out other things in its path.

Most of your symptoms lead me to believe you've got a weak electronic component, most likely in the ignition systems. But, I couldn't tell you exactly what is causing your problem.

[myersfw]

Marginally bad O2 sensors will also give that kind of performance problem. Not always good, not always bad. If mine ran for an hour or so continuously, then the missing would begin in earnest, and wouldn't stop until the engine has been stopped and cooled off.
It's a simple job, not terribly expensive or hard, the passenger side sensor is a PITA to get to and remove, but it can be done. Extensions and swivels, my man, extensions and swivels.... An O2 socket helps, too :thumbsup:
I think you'll find that new O2s will improve it, if not eliminate it.

[five7kid]

... O2 sensor has been Replaced...
Although I haven't had any issues myself, I've heard from other 3rd gen guys that Bosch O2 sensors don't always work the best. What brand did you use?

[DeMasi1990]

I used standard first, and now bosch

[LS1ZZ28]

take off dist cap and a good look at the relutor and pickup for rust/ corrosion seen this problem twice

[wastedt/a]

is your catalytic converter clogged? let it run and see if it starts to glow red.

[steveo]

i'd tend to agree that you should check the cat out, and by check the cat out, i mean destroy it until you get it running properly, because i have seen clogged cats do exactly what you describe

to eliminate it from the equation, simply take it off, go caveman and bash its guts out with a big screwdriver, put it back on and see what happens. if it gets better put a new cat on or leave it gutted. if it doesn't get better, you now have a gutted cat

those tpi speed density systems are really picky about VE, having the engine bored .030 over (you did mean .030 and not 0.300, didn't you?) might not seem like a big change, but it will screw with driveability if it isn't tuned (although it shouldn't run THAT badly), having the engine run responsively until it heats up to a certain point is a warning sign that your VE tables are way out

if the o2 sensor is functioning correctly, these engines will almost always throw a code if they're running uncontrollably rich enough to affect anything, that sort of rules out stuck injectors, major lack of ignition, etc

keep at it, they're not the easiest FI systems to work with, but they can always be fixed unless the motor is just screwed

just to be sure, you're certain nothing else was changed during rebuild? stock cam? stock-ish head gaskets? pistons? etc?

[wastedt/a]

theres no reason to destroy it thats expensive and kinda dumb. just take it off and let it run till it gets warm and see how it runs. is the smell like a sulfur type smell? thats a tell tale sign your cat is bad.

[wastedt/a]

i just read the post again and the part where u said the plugs were saturated in gas. if its dumping raw fuel down into your cat itll clog it up in no time.

[usetaboost]

This is what I would do. Pull off cat, get an AC DELCO o2, new plugs, check all vac hoses and replace anything questionable. Fire it up and check for intake leak and around your injectors. There's a reason you are supposed to put new rings on them when you pull them out. Maybe grab another map sensor off a junkyard car to swap out also. Try that and report back. Also try pulling your vac hose off your fuel regulator and see if it's leaking. Just throwing simple stuff out there to eliminate-you never know!

[Patrol32]

Well, I had this problem like 2 years ago "Injectors can check out electrically and still be bad. The only way to know for sure is to have a competent, properly-equipped shop do flow and pattern tests on each one"
I did try several thing before spotting it, i did rewire the whole engine, and change the electrical wire and connection to the injectors, and only after almost 8 months of hastle managed to solve it.