Crazy idle and reference angle questions.....

[Spence]

I few weeks ago I decided to change the exhaust and headers on my car(90 stang, supercharged). I went up in size on the headers and from 3" to 3.5" exhaust. then I changed my head gaskets as a preventive maintinence thing(have done this many times with no problems), I fire the car up and its idling ok, I fire up the laptop so I can set the timing, my Crank Ref angle is set at 10°. usually my timing table says 30° where the bubble is hovering(whole block of cells) and the box in the dashboard reads roughly 24°. well now it reads 30° in the dashboard too.....what happened?. then once the car gets alittle heat in it, the idle starts going bonkers rolling from 500-1500rpms.......then smooths out at 1100, then rolls again........A/F will be normal at 13.50:1. then it all the sudden goes lean at 15.9 and idle rolls.....I fatten it up......it smooths.....then goes crazy again and engine starts like missing......then smooths out........am I having a ground problem? did damian invade my car???????

 

[Otto J]

i would double check for vacuum leak somewhere, tha is the only reason i could see an A/F change
Otto

 

[Spence]

Found it......

on the right front radiator support there is a small ground wire....I have no clue what it goes to, but its in the same harness as the alternator wires, I guess the last time I smoked a blower belt it took that wire out and I didnt notice it, I repaired this ground and the car idles perfect again........

 

[NoSlix]

Spence,

Glad to hear you found the problem. I know how frustrating that can be. Just wondering what caused you to throw the belt in MG? You hadn't thrown one in a while before that, had you?

 

[Spence]

actually it threw the belt, pulley, support.....hehe, the bolt that comes with the vortech support was not long enough and it pulled the threads out and came apart......longer bolt cured it....