k guys I have a 88 with a 90 motor. the guys I bought the car off said the motor was rebuilt but when I got it it was idling at 3000 rpm I got it down to 1000 cold 1500 once it warms up and it sounds like it has a miss in it. also all the emissions has ben removed including bac and cold start assist. it also has no omp. any idea what cold be causing the (miss)?

second it has hesitation between 2000-3000 rpm also it has a little vibration with the hesitation. any ideas?

one more thing can I use 4 trailing plugs instead of trailing and leading? a friend said that if I run 4 trailing it acts as a hotter plug and inn returns makes the engine run better. any help will be appreciated.

thanks,
craig

 

With no OMP you better run premix..... A "miss" at idle could be MANY different things.

 

make sure you use all S4 electronics with that engine. any s5 parts may not be compatible, OMP is mechanical on the s4 block. So might want to run premix or change the Cover to s4 Cover.

 

iim running premix anf everything electronic wise is s4

 

the trailing plugs are colder, 9 is colder than a 7.

i think step 1 would be to find why it idles so high, a high idle by itself will miss.

 

okay well I think it may be plug related if thats possible but the idle screw is all the way down and so is tps screw I did notice that my throttle body isnt making full contact with tps sensor

 

okay also found out I have a leaking fuel injector