New motor, wacky idle!!

[wtfox]

So i put a new motor into my 88 LX. Before the new motor i had converted it to mass air from the speed density and it ran great. The block is bored .04" over and has an E303 cam. Timing was set dead on with the marks on the gears lined up at TDC. I refreshed the stock heads and am still using the stock intake manifold and got a remaned set of 19lb injectors.

The car starts up nice and easy but my idle is odd at best. trying to idle at 1000RPM is impossible, there is almost no vacuum (about 5") and the mixture goes super lean and the car surges and just wants to die. If you let it sit long enough it does die. The only way I can get my car to idle is to set the TPS to 1.35V and hold the idle at about 1500RPM, there i have 17" of vacuum. While driving if I shift into a high gear and the revs drop below 1500 the motor bucks. Base timing was set to 13 degrees.

I wish i knew more about stangs, but I don't. If anyone has any advice on things I should check please help me out. Maybe this is normal

 

[AdirondackFox08]

Sounds like you need a tune. Personally I would've stayed with the stock cam until you went with a good h/c/i combo. Iirc, the tps at idle should not be over 1 volt.

 

[dsblk93gt]

Have you checked the fuel pressure and verified that it is correct? If you are lean at idle that bad you will not be getting good vacuum. Even with an E303 cam you should be able to at least idle at 1000 without a tune.

 

[92BIGREDBEAST]

Sounds like a bad vacuum leak. Is your AIC hooked up and functional? EGR hooked up and functional? Soo much stuff could be the cause. Is your timing at 10 deg with the spout connector out??? I would double check the timing first. Been there man... lol

 

[wtfox]

IAC is hooked up, it was functional before i rebuilt the motor, now? EGR is disconnected but I bought an EGR delete thingy that plugs into the sensor socket. timing is at 13 degrees with the spout connector out

 

[wtfox]

well i got it to idle pretty nicely at 1000RPM. First thing i did was hook the EGR back up. Then i followed the base idle reset procedure. I was still idling a little high and running lean so I closed the throttle plate little by little and my AFR started going down!! I left it at 1000 because below that it started getting richer than stoichiometric. checked my timing and I am good to go. TPS voltage was at 1.00V, perfect! I think my problems were mostly a result of my lack of knowledge when it comes to my car.

 

[superbender]

I hate lack of knowledge,it happens to me all the time

 

[wtfox]

i learn as i go, im just lucky it isnt my only car

 

[92BIGREDBEAST]

well i got it to idle pretty nicely at 1000RPM. First thing i did was hook the EGR back up. Then i followed the base idle reset procedure. I was still idling a little high and running lean so I closed the throttle plate little by little and my AFR started going down!! I left it at 1000 because below that it started getting richer than stoichiometric. checked my timing and I am good to go. TPS voltage was at 1.00V, perfect! I think my problems were mostly a result of my lack of knowledge when it comes to my car.

Very good grasshoppa! Your TPS should actually be set at .95v but i have read other wise. I would personally set it at .95 from experience. I had live tuning software and i have set the TPS from .88 to 1.15 to see the difference in run quality and i have found that .95 works best.I am glad you have things worked out.