I would check all of my plug wire for evidence of burns or cracks. Normally once a plug fouls, that is it and it doesn't work again.

 

So all my plugs are replaced, I don't see any loss of fire when I open the hood at night in the dark and the wires were just replaced back in June. I noticed my car doesn't miss when its cold but the warmer she gets the worse my miss is. I checked the ignition control module but that tested fine and I even put a new one on just in case Advance's tester didn't test it properly, that didn't help. Next I'm planning on trying just replacing the coil since even the MSD one is relatively cheap. If that doesn't fix it I'm afraid of cosidering it may be the opti goin out. Does anyone know of any way to test it or what the symptoms of it goin out would be?

 

well they go different ways, some wont run at all, some start as a miss and get worse, some run and wont run, soo could be. opti has a life of 60 to 100k miles with some going for longer and some shorter times.

 

Well my car's at 130k still with the stock opti on it so far. On a side note tho I've been wondering if it could be a vacuum or fuel pressure leak causing my problem. I tested the fuel pressure earlier today, with key on engine off my pressure jumped to about 45psi the second I turned on the key but then almost instantly dropped down to about 15-20psi before I even started the car. Once I started her my psi held at about 37-38 but when I slowly gave it throttle my pressure never increased, just held there the whole time. If I hit the throttle fast tho as if I was accelerating hard my psi jumps up to almost 50. I was pretty sure the pressure was supposed to stay between 41-47 pretty much at all times other than idle? Also after I cut off the engine my pressure drops to 0 in about a minute. If so I have kinda serious fuel pressure leak which could make me run lean under load right?

 

lt1 should be between 38 and 42. shbox says to 41 47. sounds like the fpr or the pump. look here and see if that helps. 4th Gen LT1 F-body Tech Articles

 

I just replaced the fpr a few days ago hoping that would fix it but it didn't. I was thinkin of gettin the walbro pump but I was checking out ebay there was a Treperformance brand pump but idk if it would be reliable it not.

Update: driving home on the intersate today and she was running great, then I went to accelerate around someone and lost all power, I let off the gas to go back to cruising and she ran fine again, hit the throttle again and same thing so I let off again and she ran great, I let it cruise for a little then hit the gas again and she lost power then completely died and wouldn't start back up, just cranked and cranked

 

Well, that sucks. But on the plus side, now that it won't fire you are bound to figure out the problem.

 

whats the gas gage say? the gages on these are not the best. my first 4th gen ran out at a little over 1/8th on the gage. other than that it does sound like the pump. check fuel pressure to confirm. dont go cheap on the pump unless you like changing them.

 

I had just filled up with gas the day before but yeah I know my car runs outta gas a little under the 1/8 mark. I ordered the walbro pump but the weird thing is I know I'm not getting proper fuel pressure but when I run a test wire from the battery to the little plug under the hood I can hear it pumping fuel

 

A engine will only miss do to low fuel pressure when the cylinder is very lean. Optimal fuel mixture should be 14.7 to 1. A lean miss will not happen until about 22 to 1 ratio. You check engine lite should come on around 17 to 1 with a lean condition.

Your miss could be fuel related but I doubt it is fuel pressure or volume. If it was it would effect the entire fuel mapping. IF it is fuel related then it is a single injector issue. One injector starving a single cylinder may not set a lean code.

A lean condition could be masked by bad O2 sensors but the car should run like crap all the time and get really bad fuel mileage.