lt1

[firebirdTA20]

i need someone who knows an lt1 in and out to maybe help me get closer to finding whats wrong with mine ive fixed everything that it should have been now im just giving up on it and am about to just buy another lt1 engine. So if anyone thinks they know alot about them i will then tell everything i have done to try to fix it and tell what it is doing. Thanks.

[JoeliusZ28]

its worth a try to post up your symptoms. I know quite a bit about LT1s but i cant gaurantee im gonna know what the problem is. worth a shot.

[02redz28]

If you file your current LT1... Buy an LSX motor... Don't waste time with the LT1 nonsense... I'd try to fix what you have though.

[transampimp]

If you file your current LT1... Buy an LSX motor... Don't waste time with the LT1 nonsense... I'd try to fix what you have though.

Spend $5,000 + on a LS1 swap I'd just fix the LT1. Tell us whats wrong with her. I bet its a quick fix.

[firebirdTA20]

well here it goes. I bought my 94 trans am over the summer for way more than i should have i kinda got screwed over on the deal, i got way to excited about the car before really looking it over. When i first test drove the car it ran good but a little rough and being that im pretty good with cars myself i figured a quick tune up and it would run great. Then i went and bought plugs wires cap and rotor. I put the plugs in first and took it for a drive and it ran alot better. Later that night everything went bad basically, i went to take my girlfriend home and the car was dogging out really bad when you first hit the gas pedal but then once it got past a certain point it would regain all the regular power and be fine. I drove it a little bit after taking her home and when i got to my house my cat converter was glowing red hot. So i was told by alot of people to replace the optispark so i did my distributor, cap, wires, and i checked my plugs to make sure they looked okay, i also cleared my cat with a drill motor and a spoon shaped thing to hollow it out. put everything back together and still it ran horrible. I replaced my EGR valve since that was bringing up a code, i replaced my IAT sensor since that was bringing up a code, my left bank oxygen sensor was reading slow so i replaced that, and nothing helped. My car was runnging really lean on the left bank and it was misfireing and backfiring also so i decided to try putting a new ECM in to see if maybe something with the computer was messed up and that didnt help either. So i thought maybe i got a defective opti spark so i took it off and brought it back and replaced it a second time and checked all my wires and all my plugs again, and still nothing. Then i tryed gapping my spark plugs down since when i had originally replaced them the old plugs were at .030 instead of .050 like they are supposed to be but that only helped a little bit. still same symptoms as before. Then i proceeded to test my fuel pump and it was leaking down pressure so i bought a granalti 255lph fuel pump and replaced that and it helped quite a bit but still not the problem, i also replaced the fuel filter since it still looked to be from the factory. I checked compression on the right bank of the motor or (drivers side) and it all checked out fine i did a leak down test on all four also and they were fine for a motor with 100,000 miles on it. i never checked the left bank so i dont know about that side but that is the most difficult side to do and i ran out of daylight and havent done it yet since then. im sure ive done more to it than that but thats the just of it. I sounds horrible last time i started it, it was backfireing pretty bad and still driving bad, cuz i just drove it to my grandmas garage to put it away in a cozy place for the winter. So if anyone has any ideas that would be great cuz im to the point of just ripping out the motor and redoing everything but that costs alot of money so if i can fix it for cheaper for now i would much rather do that. Thanks to everyone who is willing to read this long list of symptoms and everything that i have done to try to fix it.

Thanks
-Pat-

[JoeliusZ28]

my cat converter was glowing red hot

this is often an indication that your catalytic converter is clogged, and its definitely not gonna run right if thats the case.

does the exhaust smell funky?

Id have a hacksaw ready to rock personally. Furthermore i could also see the EGR system having trouble from the increased exhaust pressure if the cat were to be clogged.

[WMCCjames]

He said he gutted the cat.

Look for a fuel issue on that side of the motor......sounds like you might have an injector or two that's hosed.

Also, what other codes have you pulled out of the ECM?

[JoeliusZ28]

He said he gutted the cat.

Look for a fuel issue on that side of the motor......sounds like you might have an injector or two that's hosed.

wow not sure how i missed that.

Id have to agree with james then, injectors are about the only remaining thing that is going to cause backfiring and bogging.

Try dumping a can of seafoam in the gas tank, you might get lucky and clean it out... but usually clogged injectors are stubborn. I dont know what injectors go for but it might be worth your while to replace them.

[firebirdTA20]

can you tell by looking if an injector is clogged or not? the computer isnt bringing up anymore codes i fixed everything that it first came up with and now there is no check engine light.

[WMCCjames]

No, you cannot tell just by looking at it. One thing to can do is to put your finger on the injector body with the car running...you will be able to feel it pulsing/ ticking....this will tell you if it is even trying to function. Your LT1 has some of the worst injectors GM used...they were very troublesome with high miles...the coils in them like to go dead.

If an injector is plugged it will still pulse/tick so the only real way to check them is on an injector test bench.

[meissen]

If you were closer to Collin's Automotive Repair Services, I'd say take it to him. He does an awesome job of diagnosing problems with FBodies.

[firebirdTA20]

i was just pricing injectors on summit racing and ebay and for a set of 8 26 lb. injecters it runs $280 but on ebay i found stock 20 lb. injectors from lingenfelter performance for $2 a piece but they are not gauranteed to work cuz some are used or have been sitting on a shelf for a while but 18 injectors for $36 or 8 for $280 then with 18 there has to be at least 8 that work.

[WMCCjames]

First off.....stop blindly replacing parts....you should have learned your lesson by now....that is unless you like wasting money. Second...20 lbs/hr injectors are way to small for your car. You need at least 24's. Third....test the injector coils with a DVM...this will show any coils that are weak or dead. If you find a dead injector, great, then look at buying a new set. If all the coils check out OK, then send them off and have them cleaned....PM me and I can hook you up with the best guy in the business and he is here in MI.

[firebirdTA20]

ill try testing them first with my DVM. thanks i appreciate all the help everyone has given me hopefully i find something with the injectors.

[Phantom409]

I hope you get this fixed
When these things run they are a blast

Where in Wyoming are ya??
We might be close?
I'm at 44th & Burlingame