RedRyder518

With your BLM's in the low 1-teens, you are running pretty rich and the computer is pulling out fuel. As stated before, 128 is the middle and anything below that means the computer is pulling out fuel to correct a rich condition and anything above that means the computer is adding in fuel to correct a lean condition. Obviously you are running rich, or so the computer thinks so. I would possibly look at the O2's even though your condition effects WOT. If I remember correctly, WOT and open loop do use the O2 sensors, but the computer doesn't "learn" from the readings. If you have new ones, definitely try replacing them, but only with AC Delco sensors. Hope you figure out whats wrong!

lt4 fd

I did and the idle was the same but it was still in closed loop(only idled it for 10 seconds or so)... I was going to go get gas and let it warm up to operating temp for a bit and see if it helped or did anything at all. If not I was going to take them out and put back the old ones till I resolve the issue so they dont get covered in black soot like the old ones are... What could make this happen???

lt4 fd

Well I drove it around a bit and its exactly the same so Im replacing the sensors back with the old ones tonight... Could the injectors possibly be bad and causing this... Also Are there any ignition issues that could cause the rich running condition in any way? Maybe its a couple of problems overlapping?? I might swap the fuel rails and injectors off a spare motor if I get a chance...

Guest47904

Check the MAF with a multimeter set on frequency. Check the yellow wire when you snap the throttle for a response over 7KHz. If under, clean and test again. If still under, replace it.

lt4 fd

Ive unplugged the MAF all together and it ran more or less the same on speed density....

lt4 fd

Maybe the running rich at idle and part throttle is from the O2 sensors being all gunked up, duh... and they are gunked up from improper timing or incomplete burning of fuel or something... The previous opti siezed, once I took it off I could not turn it more than a quarter turn by the use of vise grips and it sounded like it was grinding rocks inside of itself. The spline drive (its a 94 style) was very rusted possibly from the water pump leaking onto it, which had been replaced quite a while back so the leakage was not recent. Possibly when I installed the new opti something was twisted funny or I have no idea but it runs the same now as it did right before my previous opti broke and has a bad miss undre heavy load predominately below 2k rpm, only once had it missed the same way above that and it was at about 3500rpm. Which might mean the opti isnt the problem but I was curious how you check the timing and what its supposed to be... On the bad opti it had strong spark to all cylinders just like now even after it had seized so....

97 RedSS

Sounds like a small missfire to me...either by the opti(high rpm gets worse) or you got a plug wire swapped..I had 6 and 8 crossed a long time ago and my car ran great but it was low on power and had a very small missfire...

Cody

lt4 fd

Thanks for the reply, but it seems like more of a random missfire and when I put the wires on I think I did swap them and it backfired so I put them in the correct spot....but Ill double check real quick since the way they are routed I cant trace them to the source easily... nope they are not swappped it was a constant miss and had the smell of raw fuel so I put it back the way it was...

Dnlracin

Sounds like you have replaced everything but the injectors?If you have a pyrometer aim it at your header ports find the coldest one and you should have your problem!At least thats the way I tune our race cars!There not LT-1's but the principle is the same! Danny

lt4 fd

Yeah, Ive checked out and replaced plenty, I think Ill swap the fuel rail and injector assembly off the car and replace it with the one on my project car's motor... If no different Ill scream.

Oh and awesome idea with the pyrometer!

97 RedSS

If you dont have the money to spend on a pyrometer, just use a spray bottle(mist setting) with water in it..

Dnlracin

Oh yeah marking your headers with a crayon will work also watch and see if one doesn't melt away as fast as the others

lt4 fd

I swapped the fuel rail from a motor that has been sitting in my garage for a couple years complete with the fuel pressure regulator and the injectors onto the car and it runs literally on 1 cylinder. I hooked a fuel pressure gauge up to the rail before turning it on and primed it just to see and by the time I walked around it was at 20 psi and dropping quickly I would say after about 15 seconds it was at 5psi and maybe another 10 till it was nill. so I start it anyways and yeah thats when I knew it was running on one cylinder BTW there was NOT any smell of gas. So I go to check fuel pressure again and put it in the winshield so I can see it and there is none... not when I prime it not when its running on one cylinder so I was assuming thats why it was running on maybe one cylinder..??? anyways I assumed the FPR was bad so I was going to swap my old one on and seewhat happens, any other ideas??