rough idle problem

vladkalika · 11-24-2005, 05:42 AM

Just bought 1989 Supra Turbo (4th one I've owned) with bad exhaust manifold gasket. So I changed it out along with a bunch of old cracked hoses and installed new spark plugs.

Now it idles extremely rough, wants to stall, and from the tailpipe it sounds like it's missing (definitely not smooth purr it used to have). It also seems to run hot; temp gauge shows normal but underhood temp especially around turbo is blistering hot.

I double-checked ignition wires and all the sensors/plugs. Any suggestions what it might be?

mrnickleye · 11-24-2005, 08:24 AM

Well...if it ran smooth before you messed with it???? Check and double check, and back track your steps. You must be missing something. Possibly hooked up some vacuum lines wrong. Are the plug wires on correctly. Pull the plugs and check the gaps, and quality of the plugs (cracked ceramics, etc).

Misses are caused by 2 things....bad spark...or bad fuel mixture. Except of course, bad compression (usually due to a valve problem).

rays87turbo · 11-24-2005, 05:40 PM

Did you remove the CPS when you took off the exhasut manifold? If so you should probably check to see it is back on correctly, and check the timing.

vladkalika · 11-24-2005, 07:35 PM

I did remove CPS. Timing check is next.

thanks guys

vladkalika · 11-27-2005, 01:19 AM

Got the timing set, purrs like a kitten now.

Now that the car is running well, time for upgrades. Downpipe, boost controller, cold air intake......

suprra_girl · 11-28-2005, 10:07 PM

intake, exhaust, little boost

then save for hg

11-24-2005, 05:42 AM	#1
vladkalika Stock Join Date: Nov 2005 Location: San Jose Posts: 20	rough idle problem Just bought 1989 Supra Turbo (4th one I've owned) with bad exhaust manifold gasket. So I changed it out along with a bunch of old cracked hoses and installed new spark plugs. Now it idles extremely rough, wants to stall, and from the tailpipe it sounds like it's missing (definitely not smooth purr it used to have). It also seems to run hot; temp gauge shows normal but underhood temp especially around turbo is blistering hot. I double-checked ignition wires and all the sensors/plugs. Any suggestions what it might be?

11-28-2005, 10:07 PM	#6
suprra_girl 7M POWAH! ;) Join Date: Jun 2004 Location: New Zealand Posts: 2,312	intake, exhaust, little boost then save for hg __________________ Please use the forum to ask your questions as they will get replied to much faster than pming me Pics of my build. "Good girls are just bad girls that don't get caught" Do a diagnostic first!

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11-24-2005, 08:24 AM	#2
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Well...if it ran smooth before you messed with it???? Check and double check, and back track your steps. You must be missing something. Possibly hooked up some vacuum lines wrong. Are the plug wires on correctly. Pull the plugs and check the gaps, and quality of the plugs (cracked ceramics, etc). Misses are caused by 2 things....bad spark...or bad fuel mixture. Except of course, bad compression (usually due to a valve problem).

11-24-2005, 05:40 PM	#3
rays87turbo Stock Join Date: Nov 2005 Posts: 17	Did you remove the CPS when you took off the exhasut manifold? If so you should probably check to see it is back on correctly, and check the timing.

11-24-2005, 07:35 PM	#4
vladkalika Stock Join Date: Nov 2005 Location: San Jose Posts: 20	I did remove CPS. Timing check is next. thanks guys

11-27-2005, 01:19 AM	#5
vladkalika Stock Join Date: Nov 2005 Location: San Jose Posts: 20	Got the timing set, purrs like a kitten now. Now that the car is running well, time for upgrades. Downpipe, boost controller, cold air intake......