engine miss after its warm please help!!!

meat

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Apr 17, 2005
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please help me i have an 87 turbo 5spd car which i put the jdm motor in a year ago it has ran great since now if i go and start the car up in the morning it runs great and will run perfect until i shut the car off if i start up inmmediately it still runs great if i wait a little while and then start it it has a miss....i have done the following to see if i can't locate it...new plugs...coilpacks... it doesn't miss on one cylinder in particular just a simple miss across all of them...if i let the car cool down all the way and start it up it runs perfect....i am stumped now and have no more ideas please help me oh yes if this helps i'm sure it isn't a vacuum leak i removed all the emissions when the motor went in .......and i checked the vacuum hoses that are left all good..i regrounded the coil packs and still nothing a few other mkiii guys are telling me temp sensor? does that sound right please help!!!
 

shaeff

Kurt is FTMFW x2!!!!
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check all the grounds you can find. especially the little one going from the coilpacks to the motor. check with a multimeter for continuity. a bad ground can cause a miss. check and double check them all. also, just check the wires to the CPS as well, just for the hell of it.

does it have new wires? might wanna check those too.

-shaeff
 

americanjebus

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Mar 30, 2005
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i think your talking about heat soak. is it usualy in the middle of a hot day when it wants to stall. this was in another thread. after shutting off the engine then trying to restart the car stalls from the gas boiling in thefuel rail. correct me if im wrong
 
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meat

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Apr 17, 2005
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well the car does not stall it will get me anywhere i want to go it just misses along the way...
 

mkiiSupraMan18

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Apr 1, 2005
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I'd say you should have bought the MKII off of me.

I wouldn't call it heat soak, I personally think it's something to do with the coil packs, but what would heat do to them to make them screw up like that? There are 2 grounds going off of his, so I assume atleast one is actually grounded. I did, however, notice that there was some oil on the old spark plugs (from the valve covers) could this be screwing it up like that?

But seriously.... MKII... you know you want to...
 

supra90mkiii

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Apr 2, 2005
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mine does something like this... cold start, runs fine. when warmed up, runs fine. shut off, start right away, runs fine. shut off, leave for a little while, come back startup, still warm, misses, sometimes dies. but it only last for a couple seconds. i'm gonna check the plugs soon. also no codes. fresh rebuild.
 

americanjebus

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Mar 30, 2005
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i say heat cus it makes the gas boil in the rail after it sits for a while and the heat soaks in the engine bay. when you go to restart theres just boiling gas in there and it has to get it out and run uneven until fresh gas makes into rail.
i could be totally wrong but there is still chance. i know theres another thread on this just i havent realy bothered to look it up for ya.
 

shaeff

Kurt is FTMFW x2!!!!
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meat said:
if i go and start the car up in the morning it runs great and will run perfect until i shut the car off if i start up inmmediately it still runs great if i wait a little while and then start it it has a miss....i have done the following to see if i can't locate it...new plugs...coilpacks... it doesn't miss on one cylinder in particular just a simple miss across all of them...if i let the car cool down all the way and start it up it runs perfect....

although this sounds like heat soak, i doubt it is. does it still run choppy after, say 10 minutes of driving? if so, its not heat soak. after the boiled gas is out of the fuel rail, the car should run just fine.

supra90mkiii said:
mine does something like this... cold start, runs fine. when warmed up, runs fine. shut off, start right away, runs fine. shut off, leave for a little while, come back startup, still warm, misses, sometimes dies. but it only last for a couple seconds. i'm gonna check the plugs soon. also no codes. fresh rebuild.

that sounds like heat soak.


-shaeff
 

meat

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Apr 17, 2005
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no it doesn't go away after ten minutes thats why i think it isn't heat soak..
 

meat

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Apr 17, 2005
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WEIRD run higher octane gas never happened again.....just sold car anyway and replaced it the next day with a very very very clean 1 owner 87 turbo 5spd hardtop!!!