SlickTalon
10+ Year Contributor
- 37
- 0
- Jun 14, 2011
-
Medina,
Ohio
i couldn't find a thread with the same issue. some didn't start and idle at all, and some did when warm or cold or whatever else.
heres the story(I'm trying to give as much background info as i can to diagnose it better):
i get the car. runs good but had a coolant leak and check engine light. i find out the codes(two for both O2's and one for the manifold diff pressure sensor,P1400). and the coolant leak was right out of the water pump weep hole i found.
so i did the O2 sensors, head gasket and ARP studs, water pump, timing belt, plugs, wires, and all the gaskets along with it. everything was stock and i put it all back together stock, except for a K+N cone filter kit. ran great for several hundred miles.
then i get the 3 pillar pod, Autometer Boost gauge, and a Hallman Pro MBC(yes i capped the intake tube and turbo nipple, but left the BCS plugged in), and kept the boost near stock at 12psi. drove it all night after the install. ran great, except when i went past 14 psi it would come out of the BOV, so i turned it back down( stock 2g BOV sucks). then i get home and go to sleep. wake up the next morning and go to drive it and it barely starts or idles.
then, i take it up to auto zone to scan it(### i know i still had p1400, i wanted to see if i had any others). i had to keep feathering the gas to keep it alive. anything above like 1200rpm and it runs ok. i even redlined it on the way there. it was strong and held boost. but once i come close to a stop or turn i have to pop it in neutral and keep feathering it to stay on. i can get it to start, but i just have to keep feathering it.
so then today i check all my vacuum lines and finally just do the vacuum delete(for ease of diagnosis and testing). then i use a tool that my friend made(PVC pip and cap with an air line fitting) to pressurize the intake. hose clamp it onto the TB elbow and hook up the air line. no leaks, held air pressure. BUT why would it be a vacuum leak if it ran all night and then just didn't start in the morning. NO CHANGES. but i did it just to be sure.
so my only thoughts turn to that i had a bad idle air control motor, or that manifold differential pressure sensor. but i ran fine before with the p1400, so why would it cause it now. and it drove fine one night then wouldn't run in the morning. what the hell went bad over night? this things becoming a nightmare, I'm sick of working on it.....
....i JUST replaced the IAC with a brand new 1. AND the manifold differential pressure sensor with a brand new 1. STILL won't idle.
i don't know what to do now. it seems like its trying to run on just 3 at idle. just runs terrible. injectors? ignition? IDK!!!....please help!
heres the story(I'm trying to give as much background info as i can to diagnose it better):
i get the car. runs good but had a coolant leak and check engine light. i find out the codes(two for both O2's and one for the manifold diff pressure sensor,P1400). and the coolant leak was right out of the water pump weep hole i found.
so i did the O2 sensors, head gasket and ARP studs, water pump, timing belt, plugs, wires, and all the gaskets along with it. everything was stock and i put it all back together stock, except for a K+N cone filter kit. ran great for several hundred miles.
then i get the 3 pillar pod, Autometer Boost gauge, and a Hallman Pro MBC(yes i capped the intake tube and turbo nipple, but left the BCS plugged in), and kept the boost near stock at 12psi. drove it all night after the install. ran great, except when i went past 14 psi it would come out of the BOV, so i turned it back down( stock 2g BOV sucks). then i get home and go to sleep. wake up the next morning and go to drive it and it barely starts or idles.
then, i take it up to auto zone to scan it(### i know i still had p1400, i wanted to see if i had any others). i had to keep feathering the gas to keep it alive. anything above like 1200rpm and it runs ok. i even redlined it on the way there. it was strong and held boost. but once i come close to a stop or turn i have to pop it in neutral and keep feathering it to stay on. i can get it to start, but i just have to keep feathering it.
so then today i check all my vacuum lines and finally just do the vacuum delete(for ease of diagnosis and testing). then i use a tool that my friend made(PVC pip and cap with an air line fitting) to pressurize the intake. hose clamp it onto the TB elbow and hook up the air line. no leaks, held air pressure. BUT why would it be a vacuum leak if it ran all night and then just didn't start in the morning. NO CHANGES. but i did it just to be sure.
so my only thoughts turn to that i had a bad idle air control motor, or that manifold differential pressure sensor. but i ran fine before with the p1400, so why would it cause it now. and it drove fine one night then wouldn't run in the morning. what the hell went bad over night? this things becoming a nightmare, I'm sick of working on it.....
....i JUST replaced the IAC with a brand new 1. AND the manifold differential pressure sensor with a brand new 1. STILL won't idle.
i don't know what to do now. it seems like its trying to run on just 3 at idle. just runs terrible. injectors? ignition? IDK!!!....please help!
Last edited:
