Okay so i bought a 95 formula a few months ago. It has a 94 LT1 in it from another T/a or formula. Its pontiac numbers on the vin on the engine. Okay so a few wks after I bought it I stopped at sheetz to fill up, Put 92 into it and shortly after leaving the gas station the car started a really bad stumble, had a terrible idle almost like it had a cam in it. So I asked the kid I got it from if he ever had this problem and he said occasionally it would do this.(Nice toknow after picking this over a perfect 95Z28)
He said he put some octane boost and dry gas in every once and a while and it seemed to keep the problem away. I climbed under and looked and the opti had all kinds of oil/crud everywhere so I bought a summit racing cap and rotor, Taylor 8mm wires and NGK plugs, and a msd coil. changed everything and dumped the octane booster/cleaner in. After getting everything back together car works great.(thought I had it fixed with the crap all over the ignition.) Now the other day at lunch i sat in the car to listen to the radio so after 10-15min I started it to make sure battery wasn't dead and it seemed to have a rough idle. I didn't think much of it so turned it off and at the end of the day we had to go elsewhere so I took it down the street and it was stumbling a little at idle and lowwer rpms. but when I would jump on it it ran ok(down a bit in power tho). Turned it off went for a trip with the boss and came back and took the car home. it ran terribly. After about an hr or two i went to go the auto store to get some grease for the new LCA's/Panhard bar.
and It was hardly able to come up the hill so i turned right around and went back home. By this time it was getting late so i gave up for the night. Next morning and now it wont start at all. It trys to but just wont catch. I haven't got under to check the opti but the plug wires are all okay. and nothing is jumping out at me as a cause. Is there a sensor that goes bad with these engines. or could it be a fuel pump. I can hear the pump prime but thats not saying its pressuring up enough to actually run the car, I am kinda leaning toward the fuel side or electronic sensors since all the ignition parts are new. Any ideas where to start? Thanks Guys!!

 

also when it was running bad i put my computer on it and had datamaster running and no error codes other than for the A.I.R... the lterm counts was 160 in the first box and 128 in the second. Sterm was 128/128. spark advance was around 30-32 at idle and jumped up as soon as i gave it a bit of gas. Also this was in the closed loop mode. And everything else seemed to be right where it should be. Dont' know if that helps but i thought i would throw out as much info as possible to get an answer cuz she is my dd and i cant afford to have it not running. Not to mention I love driving it!!!!

 

Just crawled under there. No oil or anything anywhere on the opti so I don't think it has to do with Spark side of things. It really seems like the engine just isn't getting any fuel.

 

also if i spray ether into it it will start and run till the starting fluid burns out. I am thinking fuel pump. is there a fuse for it or is it only the relays up under the hood?

 

okay just checked fuel pressure. I am getting it to start again at least... I have 38-41 when ign. on and engine not running but within about 3min it drops to about 25... When idling it stays up in 37-42 range and when i reallly rev it it gets a bit higher. Checked ohms getting 12.3-12.6 the whole way across all 8 injectors. But it still seems to miss really bad I am getting a lot of blue smoke that burns your eyes but doesn't really smell all that rich.(like what fuel its getting is burning.)
WTF I am stumped now????
Anyone with any suggestion on what to try next

 

the check valve in the pump is bad, it should hold pressure for about 30 minutes not drop so much right away. blue smoke is bad head gasket i believe? don't quote me on that though. Also the actual optical sensor could be bad, o2s could be bad as well, or the cat could be clogged.

 

i have the fuel pump out now i read somewhere someone had a leak in the pickup hose inside the tank how do i check and see if its that or what your sayin with the check valve. the filter in the tanks good and nothing is really jumping out as the culprit?

 

also I just wanna throw out there It is way way way easier to cut yourself an access hole in the back floorboard. Just watch what you are doing cuz the lines are close but not close enough to cut as long as you use a cutoff wheel or something you can control how deep you are cutting... There is quite a few of videos on ebay and such where exactly to cut.

 

Is the check valve a part of the pump itself? Meaning do I need to buy the pump or can I change only that specific part??

 

okay after seeing the fuel pressure drop way down I followed the chilton and replaced fuel pump and now ITS STILL DOING THE SAME DAMN THING so now i am out 170.00 WTF
Anyone any ideas????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ????????????

 

My problem is kind of similar cant figure it out either

 

First I'd change the fuel filter and make sure you didn't get some **** gas. Next check the ICM and Opti harness. Alot of **** can cause your problem and chasing an intermittent problem can be costly if you continue to guess. Kault Codes and a scanner is your friend.

 

filter is new. I changed it when I did the plugs, wires and cap and rotor. Also I checked the fuel injectors all are within ohms. Could one be bad even tho it has the correct resistance. Also when I look into the tank there is what kinda looks like dirty motor oil resting toward the bottom of the tank. I'll take a pic if it helps???? Also last time it did this I put dry gas and octane boost in it and it cleared up in 2 days or so. but right after that i changed all the plugs and stuff since the opti had all kinda oil and stuff from the timing cover leaking.....

 

Guess tom. I will grab some more octane boost and dump it in and get some more gas and see if that gas in the tank is no good and when it gets low it sucks that crappy stuff up in. If it does seem to stop when i put octane boost in. I already did the dry gas it hasn't helped. Is there a way to drain the tank while in the car (since i cut a trap door to get the pump out)?

 

Also i already ran a scan with datamaster all i got was the code for the A.I.R. Pump but its not hooked up.. The Lterm was a little high in the first box 160/128. but timing and everything else seemed where they always are.

 

have you tryed starting the car with the pedal too the floor, if you replaced the pump and pressure is still bleeding down, could have possibly leaky injectors

 

X2 good call, flooding the motor and fouling 1 or more plugs. Rev it a few times to clear the cylinders and let it sit until pressure bleeds off and pull the plugs to see if any of them are wet. Check your oil for high gas content. Hate to wash the cylinders and smoke the rod or main bearings due to thinned out oil.

 

I did give it a good bit of gas when i first got her to fire. what exactly do you mean. Other than just getting fuel back into everything.....
Also I noticing it really almost seems like its rich there is a lot of moisture coming out of the tailpipe and really dark **** inside the tailpipes. Maybe I am going the wrong way with the fuel and I need to check out the spark side of things.?
--Also had two plugs out and they are a little dark but not terrible. Def not white from a lean condition.
--Spark seems really strong pulling the wire off the plug and grounding it.
--And popped all the injectors off to see if it killed the engine and number 3 didn't seem like it really made the engine bog as bad as the others, But the plug for no.3 doesn't seem like its lean(Stuck injector)
Could it possibly be stuck open maybe causing the pressure to bleed down quickly when I checked that?

Anyone Any Thoughts??!!! This blows

 

holy **** no replies? you guys are usually on it.!!!!

 

ive been watching a bunch of videos with the no start problem and mine is almost exactly the same as everyone else.! Cool!!! but the problem is noone has a solution for IT!!!!!!!!!!!
i am really starting to lean toward the opti being the problem. I noticed it actually was spitting unburnt fuel out of the tailpipes. But its wierd b/c the plugs are sparking ( anice bright blue spark when i pull the wire from the plug). I have a new opti sitting down at the auto store so I am heading down now to tear it apart and hopefuuly it will start with the new distributor.
I have another problem now tooo. when i try to crank it its like the battery is dead or the starter is fried but I took both off and took them down to the autostore and they are both fine. would the opti being bad cause this?!?!?!?
Does anyone have any input at all.