chris79792000

Just installed my new aluminum elbow with granatelli mass air sensor. Also installed a new moroso cold air intake as well. I just got a chance to take it out tonight. It seemed to miss badly and seemed like it was cutting out. I started it the other day after the install and it seemed to run fine. Also just changed out the opti, plugs, and wires. The car was running great until I changed out the intake system. My thinking is the granatelli is giving the issue. I didn't have a chance to change out the mass air sensors as I had to go to work. What d you guys think? You think that could be the problem. Also is descreening the maf a good mod or no? This is on a 96 lt1.
Thanks, Chris

96capricemgr

The granatelli is likely the issue seeing as best case it lies to the pcm about the airflow and beyond that they are VERY unreliable with a high failure rate.

I would leave the screen in a stock MAF, some intake tracts do not require a screen, like if the air path is nice and straight but that is fairly rare on these cars.

chris79792000

Thanks, I'm going to swap in the stock one tomorrow. Hope that is all it is. Like I said I just tuned it up and before the air intake upgrades she was runnin like a scolded dog.

chris79792000

Installed the original mass air sensor tonight and no luck. Seems as if the engine is getting way too much fuel and it can't burn it. When I try to rev it up it just stumbles up in rpm's and is real rough. Also get alot of smoke which I believe is due to too much fuel. Could it be the tps or a faulty fuel pressure regulator? Like I said everything was running great until I installed the cold air intake.

Injuneer

How long did you drive it after you reinstalled the stock MAF sensor? Did you reset the long term fuel corrections?

chris79792000

No haven't drove it since the maf install as it would barely run. I had to work tonight and didn't have a chance to scan it.

JGuy07

You also said you changed out the opti, plugs, and wires. Could there be a problem there or did you double check to make sure everything was placed correctly?

chris79792000

Yeah everything was good there as I ran it after the change and it ran great. This all happened after the cold air induction swap out.

RamAir95TA

Sounds like you've got a vacuum leak somewhere. Are you sure the elbow and CAI are secure and don't leak (post-MAF)?

chris79792000

yeah seems to be sealed up. I'll have to double check. Are you talking after the maf towards throttle body? I'll double check everything today.

chris79792000

Good call on the vacuum leak. I started retracing everything I've done and found that the crankcase vent on the driver side valve cover was not pushed in all the way. I was cleaning the other day and must have knocked it out. Only problem is now I think I have it flooded. It will hit now and again but won't start. When I first started it this morning it did run but poorly. I haven't been able to get it started since I fixed the vacuum leak as I'm sure that was probably the problem. It just seems to crank and crank. Like I stated before I just tuned it up so I doubt the logo is faulty. Any ideas.

Injuneer

The line from the throttle body to the valve cover is not a "vacuum" line in the normal sense. It's there to supply air from in front of the throttle body blades to the valve cover, so the PCV valve can pull the clean air through the crankcase. It might cause a very minor problem, but not the problem you are describing.

If you think the engine is flooded, put the accel pedal on the floor BEFORE you turn the key to "start" and hold it on the floor until it starts. That puts the PCM in "clear flood" mode.

You might want to check your fuel pressure, and check the vacuum line for the fuel pressure regulator for wet fuel.

chris79792000

Thanks Injuneer!! I think you may have hit the nail on the head. I let it set over night and tryed to start this morning. It wouldn't even hit so I pulled one of the plug wires and stuck a plug in it. I could see it sparking, so i i'm pretty sure it's not an opti issue. I did check the vacuum line to the regulator and it has no gas in it that I could see. Yesterday I pushed the scrhader valve and it did have fuel to it. However I don't have fuel pressure gauge so I'm unsure if I have enough pressure. Also when I scanned it yesterday it threw p 300 multiple cylinder missfire. However could that be caused by insuffcient fuel flow? I'm leanin towards the fuel pump as of now. However I don't want to change it if that isn't the issue. I do belive it sounds like the pump does come on. Something else worth noting is that the car was sitting for about 6 years with minimal starting. I did have a fuel stabilizer in while sitting. It was sitting on about a quarter of a tank. I have since put fresh premium in. Any help guys, I'm all ears and it will be appreciated.

Thanks, Chris

Psycho

Replace the fuel filter, easy job. Go to AutoZone and "rent" their fuel pressure gauge. It is free if you return it. That will definitively tell you whether it is the pump or not.
You can also manually prime the engine by using the prime plug on the passenger side fender. Just apply +12V to it.
http://shbox.com/1/fuel_pump_prime.jpg

chris79792000

Thanks, I'll try that.