Engine cutting out, need help soon please

[mustang88]

i just got a 1988 mustang gt 5.0 bored to 306,msd distributer,malory coil,ported and polished heads, and ford racing cam i do believe. when the car is in neutral it revs up high,as far as it can go, but when driving the car and getting to 3000-3500 rpm's the engine starts acting like its not getting enough fuel and wont stop untill it gets back to the lower rpms> below 3000.

somone who had it before me thought it was the wireing harness(maybe the one below the dash). but i though maybe because the low voltage light stays on might be because its not getting enought power to somthing. the engine was rebuilt and the stuff above was added to it during rebuild i think. i thought also the msd distributer and malory coil could have a error and cause this?

i dont know for sure and am in need of help . any help is appreciated
thanks

 

[DMAN302]

Check if car is converted to mass air, if not your computer is likely VERY confussed by the mods and will require you to convert to mass air setup. This is easy to do but can cost up to 500$ if the summit kit is used. Result is a well running modded car. Good luck and enjoy the car, oh yeah welcome to stangnet.

 

[mustang88]

thanks

thanks for the responce, i will check on that

 

[HISSIN50]

i would address the charging system first. you very well could be right that you dont have the juice to spark decently at higher rpms.

have you pulled codes? you need a code reader (under 30 bucks) or a test light to do it (unless your car is a Cali car, it should not have a functional CEL). if so, try to use it to pull codes if you want.

if you have a FP gauge, i might hook it up or check it out during the times you are running out of wind.
i might also find out what cam you have. if not, check your vacuum reading at idle - SD cars require stockish vacuum (15-20" at idle) to work right.

good luck and welcome to the boards.

 

[TrickStang37]

i just started having the same problem today. gonna change the dist cap tomorrow, last time it was doing this was 3 years ago, and it was with the same brand im using right now too. if not, what can it be? sometimes its running perfect and then other times it'll sputter bad on the low end. sorry to steal your thread.