Not-good starts
Thread Starter
Staging Lane
Joined: Jul 2010
Posts: 51
Likes: 0
Not-good starts Hey guys, basic build info is in my sig but if you have other questions I can answer most anything.
So basically I have an issue with cold starts (this goes for weather and engine temperature).
Warm weather starts:
When the engine is cold the engine will turn over and start very well, but then within a minute (or less) of idling the idle drops to about 550, and if the engine is cold this is low enough to kill it 50% of the time if I put it in drive.
Cold weather starts:
When the engine is cold it'll start very well, but again shortly after that the idle drops. But in cold weather it drops further, to about 450-500. If it's colder it's worse, and it'll die in park/neutral even about 50% of the time.
All weather warm starts:
Warm starts are never an issue, it always starts fine and idles in park around 900 and drops to about 600 in drive, and when engine is warm this is perfect/never dies.
This idle issue seems to fix itself after a short period of driving, so I kinda just lived with it for awhile but I do want it fixed.
Currently my guesses (in order of what I think is most likely) are:
Tune-related (open/closed loop maybe?)
Throttle body related (BBK 58mm)
Temperature sensor? If memory serves me right there is a temperature sensor that causes this sort of issue, but I could be wrong since I'm remembering info I learned a long time ago reading the forums.
Any help is greatly appreciated, brainstorming/ideas are always a good thing. lol
P.S. Happy New Years everyone!
So basically I have an issue with cold starts (this goes for weather and engine temperature).
Warm weather starts:
When the engine is cold the engine will turn over and start very well, but then within a minute (or less) of idling the idle drops to about 550, and if the engine is cold this is low enough to kill it 50% of the time if I put it in drive.
Cold weather starts:
When the engine is cold it'll start very well, but again shortly after that the idle drops. But in cold weather it drops further, to about 450-500. If it's colder it's worse, and it'll die in park/neutral even about 50% of the time.
All weather warm starts:
Warm starts are never an issue, it always starts fine and idles in park around 900 and drops to about 600 in drive, and when engine is warm this is perfect/never dies.
This idle issue seems to fix itself after a short period of driving, so I kinda just lived with it for awhile but I do want it fixed.
Currently my guesses (in order of what I think is most likely) are:
Tune-related (open/closed loop maybe?)
Throttle body related (BBK 58mm)
Temperature sensor? If memory serves me right there is a temperature sensor that causes this sort of issue, but I could be wrong since I'm remembering info I learned a long time ago reading the forums.
Any help is greatly appreciated, brainstorming/ideas are always a good thing. lol
P.S. Happy New Years everyone!
My guess is the aftermarket TB....when did you start having issues? Before or after you put it on? I doubt its the coolant sensor...when that goes bad like mine did it just tells the PCM it's always negative 40 degrees LOL and dumps fuel making it run rich as hell...if that were the case it should start up with no issues if it's cold. Maybe try putting the stock TB back on and see if that solves it. It's also possible it's a tuning issue...a good dyno tune is a lot better than a generic mail order tune (not to bash PCM for less, I also had a mail order tune from them, but my dyno tuner picked up 11hp over their tune and improved driveability quite a bit.)
Thread Starter
Staging Lane
Joined: Jul 2010
Posts: 51
Likes: 0
My guess is the aftermarket TB....when did you start having issues? Before or after you put it on? I doubt its the coolant sensor...when that goes bad like mine did it just tells the PCM it's always negative 40 degrees LOL and dumps fuel making it run rich as hell...if that were the case it should start up with no issues if it's cold. Maybe try putting the stock TB back on and see if that solves it. It's also possible it's a tuning issue...a good dyno tune is a lot better than a generic mail order tune (not to bash PCM for less, I also had a mail order tune from them, but my dyno tuner picked up 11hp over their tune and improved driveability quite a bit.)
Wish I could find someone who does speed density dyno tunes. Seems like I'll have to make a huge road trip to PCMforless to get it done. Nobody else has the in-house capability it seems. :/
Thread Starter
Staging Lane
Joined: Jul 2010
Posts: 51
Likes: 0
SW corner of Michigan. I've contacted a bunch of shops and none of them have the ability to burn a new chip. It's not the speed density part that's difficult, it's that '93s actually do use a chip for tunes whereas '94+ use a reflashed PCM. lol
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