chris79792000

I tried the manual purge and it still didn't start. I could here making noise like fuel was coming in. Heres what I found out so far. I haven't had chance to get the fuel pressure gauge. However I cycled the key and then pressed the schrader valve and a small amount of fuel came out. Not sure how much should be present by just cycling the key. Next I supplied power to the manual purge and then pressed the schrader valve and I got a steady stream of fuel then. I'm complety stumped write now. Like I said I checked and it does have spark and one would think there would be fuel since when I do the manual purge I am getting fuel to the engine. So I can't figure why it won't fire. Now when I tuned it up I only put on a msd cap and rotor as it had just a little corrosion on the rotor tip. Could the optical portion of this now be bad? I'm reaching now. I just don't get it the dang thang was runnin good before the cai install. I'm sure that is not the issue it has to be something else. Could the injectors not be pulsing? Any help would definatly be appreciated at this point.

Slo-LT1

Just a thought have you checked for an injector that may be stuck open or not working at all? to test an injector just get a multimeter and check the resistance of each one from the contacts where the plug goes, I can't remember what the resistance should be I think 12.8 ohms either way just check a few and see if they are all around the same resistance, If one is way off or does not have any resistance then you have found the problem.

PWR SHFT

Unplug the MAF and try and start it. This will force the computer into limp mode and run under the standard tables in the computer. This will rule out everything in the intake path all the way to the throttlebody. If it is still running like crap or won't start you may want to check the opti. You said earlier that you replaced the opti. What did you replace it with? If it was a cheap aftermarket unit, they are KNOWN to have serious reliablility issues. Only use genuine ACDELCO/DELPHI units. MSD's are also known to be unreliable. If you search on this you will see what I am talking about.

chris79792000

I tried unplugging the maf and it still won't start. I replaced the just the cap and rotor with a msd. I still need to check the injectors and if they check out I'm leanin towards rplacing the whole opti with an Ac delco. It just doesn't make sense as It was running good and only has about 20 miles on it since the cap was installed.

PWR SHFT

Sounds like the rotor may have fallen off. Did you loc-tite it on?

Kevin Blown 95 TA

What do your plugs look like?

chris79792000

I loctited the rotor. haven't checked the plugs yet. Have to work the next couple of nights. Will check on Friday. I believe it's either fuel related or opti related.

Thanks everyone for the help thus far, Chris

Injuneer

Unplugging the MAF simply causes the PCM to default to speed-density mode for calculating the mass air flow, using the VE table. From that point on, it manages the engine normally. Unplugging the MAF sensor simply rules out a problem on the MAF sensor circuit. "Limp mode" is reserved for situations where the PCM loses almost all of its inputs.

chris79792000

I'm going to check the fuel pressure and then injectors. If those are working properly it's hello opti again.

PWR SHFT

What I meant to say. It's been a while, Fred. I'm a bit rusty.