Hey Y’all,
Never had an F.i Mustang. Just picked up an 86 GT vert.
88k miles. stock everything Took it home, installed headers back exhaust w/ cats
70mm tb(I know too big probably)
Removed smog pump and sealed vacuum lines and holes in heads
after the work was done, she was idling rough. Surging like crazy. Smelled rich af( burning my !)
pulled the codes 21,31,42,92
Then did a
Smoke Test:
EGR valve was leaking
Removed the EGR and capped the vacuum lines, blocked off opening
replaced ECT (code 21)
still surging, I decided to smoke test again ( I’m smoke testing theough the vacuum tree?)
No leaks
-pulled the pcv, plugged the hole and the line( check intake leak) no suction at filler breather
-tested fuel pressure, all good
Vacuum test***12in at idle, consta
Like a noob, I just figured, Imma throw an IAC at this thing and do a reset
—this actually worked for about 25minutes then it started surging again
ran the scanner again. 31(egr gone), 42,92 richy rich. Did the cylinder test also. All are good
Replaced the 02 sensors, no change
still surging
I’ve been over timing, tps voltage, several smoke tests, idle resets
the car drives amazing, the idle is just completely screwed. I mean it really cruises nicely, just when let off she’s pulsing and not being nice
This car actually has a smaller 55 series battery in it. The battery bled acid all over my new driveway a few weeks ago right before I worked on it. Hasn’t happened since. Will probably replace with a proper size tomorrow
Never had an F.i Mustang. Just picked up an 86 GT vert.
88k miles. stock everything Took it home, installed headers back exhaust w/ cats
70mm tb(I know too big probably)
Removed smog pump and sealed vacuum lines and holes in heads
after the work was done, she was idling rough. Surging like crazy. Smelled rich af( burning my !)
pulled the codes 21,31,42,92
Then did a
Smoke Test:
EGR valve was leaking
Removed the EGR and capped the vacuum lines, blocked off opening
replaced ECT (code 21)
still surging, I decided to smoke test again ( I’m smoke testing theough the vacuum tree?)
No leaks
-pulled the pcv, plugged the hole and the line( check intake leak) no suction at filler breather
-tested fuel pressure, all good
Vacuum test***12in at idle, consta
Like a noob, I just figured, Imma throw an IAC at this thing and do a reset
—this actually worked for about 25minutes then it started surging again
ran the scanner again. 31(egr gone), 42,92 richy rich. Did the cylinder test also. All are good
Replaced the 02 sensors, no change
still surging
I’ve been over timing, tps voltage, several smoke tests, idle resets
the car drives amazing, the idle is just completely screwed. I mean it really cruises nicely, just when let off she’s pulsing and not being nice
This car actually has a smaller 55 series battery in it. The battery bled acid all over my new driveway a few weeks ago right before I worked on it. Hasn’t happened since. Will probably replace with a proper size tomorrow