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Discussion Starter #1
Finally got car to run. It is running pig rich and will not idle. I am thinking that either an injector is bad or the fuel pressure regulator is bad. If I pull the vacuum to the AFPR the gage hits 80psi. From what I have been told this is incorrect. I have a new Kirbon unit and 42# injectors. Does anyone know of an easy way to check any of these componets.

Thanks
 

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I am having a similar problem but my fuel pressure does not go up that much when I unplug the vaccum. I have not had any luck so far but I will let you know if I find out something.
 

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How long have you had this set-up and what has changed recently to cause a problem? Do you run rich all the time or just at cetain rpms? Are you rich when the blower is running? What makes you think you are rich?

You should run 38-40 psi at idle with the vacuum unhooked. Try setting the pressure first. If you are truly running 80 psi that will cetainly cause problems and rich conditions.

If that doesn't solve the problem, look for exhaust leaks - they will quickly make you run rich because the O2 sensor reads the mix as lean from the air leaking in and calls for more fuel. Also look for vacuum leaks, they can do the same thing. A vacuum leak may explain the wild pressure readings also, but I wouldn't bank heavily on that.

If you still have a problem, adjust the TPS and IAC/IAB. If none of this fixes it, you will have to start suspecting the MAF calibration.

You also may have to use an EEC-tuner or similar device to control the PCM/AF mix. The PCM will have injector pulse widths for stock injectors and they will be much too long for the 42# injectors.
 

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Discussion Starter #4
Good ideas non-stock. Everything listed in my signature was part of this winters project. It is all new which makes it hard to trouble shoot. I am beginning to suspect vacuum leaks or a bad regulator. It will not idle and runs terrible below 1500rpm.

Thanks for the tips, will check this evening
 

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I didn't notice in your sig if you have a chip or an EEC Tuner. If not, you may need one. The Lightning MAFs are notoriously rich at idle on 302's. Basically what has to happen is you will either have to have a tuner burn a chip or use an EEC Tuner to lean out the MAF curve from 0-2000 about 35%. That will get you in the ballpark. From there, you just need to play with it.

My car with a Pro-M 80mm and 42s will not idle without a chip or EEC Tuner. The Lightning MAFs are probably the best MAFs out there, but they are a bit worse for idle characteristics (stock). They are calibrated to have a nice idle on a 5.4 L engine...

It probably is a good idea to check for vacuum leaks etc. also.

Good Luck!!

Don
 

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I didn't see anything in your sig about the ECM, but I know that the stock ECM is VERY sensitive to changes. What cam are you running?

The FPR isn't suppose to go to 80psi. Its either stuck or adjusted in way to far. Put the stock back on and see how it runs. Your rich because the fuel pressure is too high.
 
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