88 GT Hesitates When Cold --- differs from archives (Starts Immediately) (Page 1/1) reinhart NOV 27, 01:29 PM Searched the archives and seems like all the hesitation issues were coupled with difficulty starting with long crank times. 88 GT V6 automatic: Car always starts quickly and easily. However, when engine is cold even on 80-90 degree days, it hesitates during the first 30 seconds of driving, then runs perfectly after that time has passed. Has no trouble hi-revving. Fuel system seems to be in order: Passes all fuel pressure tests, I cleaned injectors with an ultrasonic parts cleaner and verified spray pattern, also I have the fuel tank dampener -- not the mini hose that everyone loves but always fails. Electric: Tried replacing IM - no change so switched back, new spark plug wires. Engine has about 125Kmi. Do sometimes get a quick smell of oil on startup if I back up the car immediately I smell it (slight valve seal leakage?). Don't think valve seals would cause my hesitation issues tho would they? cartercarbaficionado NOV 28, 03:55 PM quote Originally posted by reinhart: Searched the archives and seems like all the hesitation issues were coupled with difficulty starting with long crank times. 88 GT V6 automatic: Car always starts quickly and easily. However, when engine is cold even on 80-90 degree days, it hesitates during the first 30 seconds of driving, then runs perfectly after that time has passed. Has no trouble hi-revving. Fuel system seems to be in order: Passes all fuel pressure tests, I cleaned injectors with an ultrasonic parts cleaner and verified spray pattern, also I have the fuel tank dampener -- not the mini hose that everyone loves but always fails. Electric: Tried replacing IM - no change so switched back, new spark plug wires. Engine has about 125Kmi. Do sometimes get a quick smell of oil on startup if I back up the car immediately I smell it (slight valve seal leakage?). Don't think valve seals would cause my hesitation issues tho would they? could be lack of valve sealing when its cold til the exhaust valves seat up from extra heat.. i did have a very similar issue on my 88 formula (v6 5 speed. did it with a 4 speed too) and i think ours was a icm and a few other things and after i did the heads it was real bad after that. pretty sure i torched a valve seat by setting the preload with new lifters and old springs. does the vacuum signal from a gauge look nice and smooth? is the egr slightly leaky? is the csi leaking just before the intake gets some heat? is the cold start programming being funky? ive found those are the most common issues other than the 2.8l losing compression while sitting usually at a higher mileage like my 87 (how it got to 200k i dont know) reinhart NOV 28, 05:45 PM My understanding is the cold start injector only fires during cranking. I did clean it when I cleaned the other injectors but don't think it should have any affect on driving. Regarding vacuum, it is idling just fine when cold started and no vacuum leaks. Are you asking what the vacuum is when I drive away? Not sure if I can get that while I'm driving. Don't have an EGR leak or I would have a high idle. cartercarbaficionado NOV 28, 06:03 PM quote Originally posted by reinhart: My understanding is the cold start injector only fires during cranking. I did clean it when I cleaned the other injectors but don't think it should have any affect on driving. Regarding vacuum, it is idling just fine when cold started and no vacuum leaks. Are you asking what the vacuum is when I drive away? Not sure if I can get that while I'm driving. Don't have an EGR leak or I would have a high idle. you can have a internal egr leak without a high idle, like the exhaust leaking into your intake, and i mean like how many inches of mercury and how smooth is it when idling, that will tell you of any valve issues, good compression and good sealing valves gives you a rock solid needle at about 14 ish on a stock cam