I need some advise about my LT1, I have been searching for possible solutions for the Intake Backfire problem. I am running out of options for repairs.
Car: 94 t/a with 130K
recently developed a Intake back fire, nothing major I could still haul *** in the car. Problem got worse where anytime I put the pedal to the floor, the car would hesitate, sputter and pop. I let off and I can ease into the gas up to 70+mph with out a hic up. Then the car died out on me on the road. wouldn't start just crank and crank, no fuel pump I could here. Car cooled off, fired right up. as I am driving I can put the car in nuetral and i can rev all I want with no backfire. Put it in Drive it backfires....Also car takes some cranking to start when cold before it fires up
This is what I have replaced since..

TPS
IAC
Plugs
Wires
Opti
Coil
ICM
With the same problem still existing, should I do 02's and a MAP sensor? its really annoying I havent pin pointed the problem yet Car is throwing no codes what so ever

Thanks

 

Fuel filter. Problem solved

 

I changed that before I had the issue @ 115K, Any one else??

 

Take out the O2s and check them. does it seem to be running rich or smoking at all.

 

Possibly the pcm going bad?

 

Not smoking at all, Though after driving the Chrome tail pipe does brown up from the exhaust but I think that's normal being a daily driven car.

 

That thought came across since I have no SES light, However as I kept applying more gas to the car to go faster, I can eventually get it to open up, but when it down shifts(2nd) it wouldnt shift back in to gear(I think 3rd) it just holds at around 5k so I let off and just baby it and it goes into OD(4th)

 

I thought the computer didnt even read the o2s or MAP at WOT. Is there any difference with how the car runs from when you first start it cold to when its warmed up? I would do a leak down test.
Jason

 

have you checked fuel psi while running at the speed that this occurs?
almost would bet you need a fuel pump.

 

most likely your coolant temp sensor. its running lean causing the backfire

 

+1 on the fuel pump.

 

The car will start right up after it is warmed up.

I did not check the Fuel PSI, Fuel Pump is a job I dread the most. I dont think it would be bad as a opti though! I wont be pissed if it doesnt solve my problem since the car does have alot of miles on the pump which I assume is original. I will test it though for sure. What is the stock PSI??

Temp Sensor.. or is it running lean cause of fuel pump going out..?

 

i would re flash the PCM

 

Sorry, didn't know the gas pump you get fuel from is in a hermetically sealed chamber, not letting any bad things in. I've gotten a clogged fuel filter in ONE WEEK. My friend? Over night. 15K miles is quite a long time. You could humor me and spend $6 on a new one, and add it to the list. Not like it's a 5hr job to do. Heck, is it 5min? Usually you start with the cheapest that make sense, and go to the biggest. When you tromp on the gas, the motor wants more fuel, if the filter is clogged it sure won't get it. It'll sputter and spat out both the intake and exhaust, it'll go away when you let off because..... it doesn't need fuel. It won't do it when you're easy on it because.... it's not asking for that much, and some IS getting to the motor, or else you wouldn't be able to drive.

Sorry, I've been watching House M.D. for the past 24hrs (Season 1 and 2, my own lil Marathon for S3 finale tonight! ), but I still strongly stick by it being the fuel filter! If not, I"m sorry you were out $6, or even $10 if they over charge out there.

 

what kind of opti did u replace it with. please dont tell me anything other than msd, dynaspark, or gm. please!

 

lol Didn't you jsut list the only 3 there are? Well ok NM, 4, there's Accel as well. Everything else that I know of is a rebuilt AC Delco (GM).

 

no there is summit, and local parts stores versions of the opti's also i also think jegs has there own version.....all of which are ****

 

So none of those are just rebuilt cores? They all have their own parts made for them to their own spec, instead of GM spec? I'm honestly asking, because I don't know lol Not to be a dick.

 

its ok, but the accel, summit, jegs, etc. are brand new units. im also guessing the autozone units are to, because im pretty sure they have a lifetime warranty. now dispite the warranty it doesnt make them a good unit. a friend of mine bought a summit opti and the rotor screws backed out of it within (im guessing) 2000 miles. as far as spec goes, im sure alot of them use GM's spec, but the quality of parts just isnt there, which is how they sell alot cheaper. that being said ive read guys destroying accel, jegs, and autozone opti's just as much. there are a few high hp guys still on a gm unit. i always look at a part as, you get what you pay for. id rather have the car sit for alittle longer to save up for the best of the best, or something close to it. for example i was in a hurry for my headers and got pacesetters, they are now rusting and look like hell. what i should have done is just saved the money for the kooks and have been done with it. ive learned my lesson from that and try to pass it on to everyone else. "best bang for the buck" theory works for awhile but isnt always the greatest route. (yea i know i kinda went off track alittle, but also tryin to prove a point lol)

 

Fuel Filter wouldnt hurt to do again, I will do a leak down test first before anything.

Opti was replaced with a MSD, 515.00 was a better price to pay than 674.00 that GM wanted for their P.O.S.