kev85rx7gsl-se

[attachment=43785:1985_RX_...L_SE_013.jpg]hey how its going....i am new here and just bought my 85' gsl se about a month ago. i have been having a problem with it idling / running at operating temp, it starts and runs fine until it gets to full operating temp and then sputters and dies.....i have checked the battery, throttle position sensor, AFM, new spark plugs, done the ATF trick, alternator, thermostat, fuel pump seems to be workin fine........i am running out of ideas? it runs great when its cold, i ended up changing the thermostat because it never got up to running tempature and now when it does it will idle up then drop, idle up then drop....higher and lower until it dies......when let the engine cool down and it will start and run fine again until it warms up??? Anybody got any clue of what could cause this.....?????

SEDave

One, it could be the engine coolant temp sensor on the back of the water pump. Two, it might be the adjustment of the fast idle cam on the side of the throttle body, especially if you have cleaned or messed with it. What rpm is it idling at and dropping to? Also, if the engine speed is oscillating like you say that's usually the TPS but you have checked it. Did you check it with a multimeter?



Good Luck,

Dave

kev85rx7gsl-se

i haven't checked the temp sensor.......yes i did clean / adjust the fast idle screw. it is idling at 800 rpm's (when cold) then when it gets warm it goes up to about 1200 rpm and drops to about 300 rpm until it dies.....yes i checked the TPS with a multi-meter using the Factory Repair manual (not Chilton) i got off a thread from this site.....thanks for any help you can give me dave

SEDave

I had a situation similiar to yours for awhile. Whoever owned the car before me must have screwed with the fast idle cam as with alittle bit of everything else. I set the TPS and it's a fincky bastard as you may know, diabled and removed most of the emissions equipment, replaced the O2 sensor, adjusted the idle speed and mixture and dashpot. Even after all that, I had to hold the throttle on cold days to warm it up and it had an intermittent problem of when it was above or at normal opt temps, the idle would drop to 300-500 rpms and die occasionally. Eventually, I discovered that it was the fast idle cam. For one, it allows for fast idle and two, it keeps the throttle plate from closing to far to allow proper idle. Once adjusted, the fast idle cam should kick in and idle around 1500-2k and gradually drop down to 750-1k once warmed up. Now, this was the solution to my case and it may be different for yourself. Here are few documents that might help. Dave.



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SEDave

Oh, and check your timing on both leading and trailing ignitions. How does run while driving?

kev85rx7gsl-se

hey thanks....i'll go through the docs you sent and will try it this weekend.....as for running, it runs great when it is cold.....drives absolutly great, then when it gets warm it sputters when you give it gas, just wanting to kill it......thanks again dave, hopefully this will help

SEDave

http://www.mazspeed.com/diagnosingdr...typroblems.htm



Check out this link. It could help.

kev85rx7gsl-se

i tried adjusting the high idle....it helped but didn't fix the problem. i did notice that if i keep the engine above 1500 rpm's that i don't get the sputtering problem?? the car will run fine until i let it idle when already warm for about 1 - 2 minutes (no problems if cold?). i haven't changed the water temp sensor yet (they sold me the wrong one, i should have checked)....i also plan to change the O2 sensor, and install my air/fuel gauge that i have....maybe that will help diagnos the problem?? i checked the timing and it was fine........i even drove the car up and down the road while warm and it did great.....pulled into the drive way and let it idle for about 2 minutes then it starts the sputtering, died and wouldn't start until it was fully cold again???

kev85rx7gsl-se

alright, i found out that i can get the water temp sensor, fuel filter and O2 sensor for about $60 all together.....i am planning on purchasing these today and hopefully installing them today also......i will let you know if it helps at all.....

SEDave

Sounds like it is running really rich at idle. The A/F gauge will help alot in diagnosis.