[stanger19]

I have a 1987 5.0L Mustang converted to mass air.I have done some mods to it and I can't get it to work right.Some of the mods are : GT 40 upper and lower intake, 70 mm throttle body and spacer, 24 # injecters, 73 mm mass air meter calibrated for 24 # injectors, 190 LPH fuel pump and regulator, X 303 camshaft, eldelbrock performer cylinder heads, BBK shorty headers and 2 1/2" off road H pipe, Flow master mufflers, 2 1/2" tail pipes, 3600 stall converter and 4.10 rear gears.When I start the car it takes a minute or so before it drops down on idle.It goes up to about 1500 RPM and then after waiting a while it comes down to about 900 RPM.It is flooding really bad and putting black smoke out the tail pipes,it gets worse as the engine warms up.If you unplug the IAC motor the idle works correct but still flooding bad.The TPS is set at 0.98 Volts and timing is set at around 13 degrees tried different timing settings but don't help.The engine is shaking really bad not working the smoothest.Have anyone got any suggestions?

[jerry_dawg]

After which mod did the problem start to occur?

[stanger19]

The car was running excellent stock no Mods.I installed a E 303 Camshaft and the idling problem started and I couldn't figure it out.I changed the mass air meter,throttle body,IAC,TPS but it didn't change anything.As much as I hated driving the car like it I used it anyway.This year I installed the X 303 cam and the edelbrock heads.Now I still have the idling problem plus the flooding and working bad.

[FrankenStang5.0]

i have the same problems as you and witht he idling high and shaking engine. check your harmonic balancer or the dampner and if its shaking then its shot. about the idle problem, i also have put a 70 mm TB and mass air kit on my car and my idle was high after we put it on. i think its my smog equipment cause me farked with that. check your wires or re gap your sprak plugs. maybe a tune up

[128chris]

Ive just gone through the same thing as your going through now. With a bunch of tweaking and help from these guys, i just about got it now. Ill tell you what ive had to do, maybe you can try these, maybe it will help. !st check the vacuum, mine was good, so i scatched that off. Then try the fuel pressure, you have it and it doesent vary. Unhook your battery, clear the codes. Fire it back up and let it idle till operating temp, without hitting the gas or anything so the computer can adjust for your new mods and settings. If not that, then try backing off your fuel pressure, i have mine at 36. That almost curred mine. Then i replaced my map sensor, reset my computer again, and now seem to have it right. Im gonna replace my egr this week and i should be good to go. Hope any of this might help you.

[stanger19]

Ok thanks for the info and I will try some of those things.

[stanger19]

After a long day I have some of the problems fixed.I checked the compression and on a couple of cylinders there were no compression.The rockers needed some more ajustment and now I have the compression up to about 180 lbs on each cylinder.Now the only way I can get the engine to idle right is to unplug the IAC motor.When the IAC motor is plugged in the engine is running rough and when you gives the throttle a shot of gas the engine takes awhile to come down on it's idle.but when the IAC motor is not pluged in it works perfect.Can anyone tell me what could cause this to happen?

[Kustomkote]

Been working with an 88 for 3 years. Your x 303 cam has a very high lift and duration and I wouldn't expect an idle below 1100 or 1200. As for things like timing, I have never been able to get a smooth idle below 30 degrees of advance. My 5.0 with an e 303 cam, stroker kit and 24lbs injectors, Speed density to MAF kit runs smooth with 34 degrees advance, 36lbs fuel pressure. If you sensors are good then try playing with timing. If that doesn't work then your cam might just be too big.