surging issue with my procharger

[svtmofo]

I have a 1993 mustang GT with a P600B procharger, I had it tuned last fall at MD they did a great job. The only thing they couldnt do is fix the surging problem, we got it narrowed down around the MAF it was reading low at low speeds but at WOT it was reading regular. I cleaned it and put it back on as they told me to do and its still surging. it only surges when crusing at low speeds, at WOT its not an issue, it runs great, but as soon as you let off the gas or cruise at a speed between 10-45 mph it bucks like a horse. It has a draw through MAF on it now. Im going to go to a Blow through here very soon. Im also replacing the tps. Does anyone have any input on what may be causing this? Does the MAF sound like its the cause? any input would be awsome.

[BIGHONKEY]

AICV, MAF, air leaking before MAFS, vacuum leak, and perhaps a problem with your evaporative system. o2 sensors also can cause that.



Check hose from FPR to intake for cracks. Maybe get one of those stethiscopes to find the leak if at all. Borrow someones MAFS would be my 1st choise.


I have had this problem with several cars. One was a craked intake tube inbetween the MAFS and TB. Another was a AICV air idle control valve. One needed a new hose from the fuel pressure reg and intake man. Another was from a previos owner toping off the gas and ruined my charcoal canister.

[svtmofo]

thanks man yea i didnt think of th AICV. The O2 sensors are new, and I kinda looked at the hoses, might want to look at them a little closer. but i got a few things to go on, thanks again

[ibstrokin]

What is your idle rpm?

[svtmofo]

im not 100% sure but i think its 900-1000 somewhere close to that

[NXcoupe]

Monitoring your maf voltage at that rpm/speed range would be helpful. You can do that by running two wires out to your maf meter connector, and having someone watch a voltmeter connected to it inside the car. Post up what you find. Also, your timing could be too retarded at that part throttle position. I have found that the SCT tunes have poor part throttle timing maps. Hope this helps.