sluggish supra

SupraDave · 07-21-2005, 03:37 PM

This is Dave from York, PA, the owner of a very nice 1986.5 Supra (n/a of course) with 79,000 orig. mi.

A little history...
I've read just about everything on this website and have been able to correct a few minor problems.
1. I have no engine codes
2. The car idles well (cold at 1,100 rpm and warm at 700 rpm). I'm fairly sure this is correct.
3. Air Flow Meter was bad and was replaced. Tested with ohm meter.
4. was getting that fresh gas smell in the cabin so I disconnected the charcoal canister and sealed off the vacuum lines. Left the line from the gas tank open to prevent pressure from building up in the gas tank. (found this tip on this, or another web site, not sure) Works good.
5. Set timing per the online TSRM.
6. Added new spark plugs...Bosch Platinum...(are these bad plugs for this car?)
7. There are no air leaks between the AFM and throttle body.
8. I adjusted the TPS per the online TSRM.

Here's the issue...
The car runs well while cold, but when the car warms up I get what the TSRM calls muffler explosion (not backfire) on deceleration. The car is also very sluggish at normal operating temperature, but it idles without any problems.

The TSRM has many possible explanations for this condition. I would like to know what the most likely problem is, so that I don't waste time and money trying to fix.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
My supra seems sluggish..	Animosity	MKIII Supra	10	06-19-2010 04:02 AM
Begginer to SUPRA and cars, I GOT A FREE SUPRA, PLEASE HELP!!	89MkiiiSupra	Non-Generation Specific Questions	5	06-01-2010 06:48 AM
Kill Board!	Isphius	Show n Tell	95	01-25-2010 05:05 AM
Questions about MKIV Supra	ukno0003	MKIV Supra	5	11-06-2008 10:53 AM
Dream Offer	Karma_Supra	MKIV Supra	22	10-17-2007 03:04 PM

07-21-2005, 03:37 PM	#1
SupraDave Stock Join Date: Jul 2005 Posts: 11	This is Dave from York, PA, the owner of a very nice 1986.5 Supra (n/a of course) with 79,000 orig. mi. A little history... I've read just about everything on this website and have been able to correct a few minor problems. 1. I have no engine codes 2. The car idles well (cold at 1,100 rpm and warm at 700 rpm). I'm fairly sure this is correct. 3. Air Flow Meter was bad and was replaced. Tested with ohm meter. 4. was getting that fresh gas smell in the cabin so I disconnected the charcoal canister and sealed off the vacuum lines. Left the line from the gas tank open to prevent pressure from building up in the gas tank. (found this tip on this, or another web site, not sure) Works good. 5. Set timing per the online TSRM. 6. Added new spark plugs...Bosch Platinum...(are these bad plugs for this car?) 7. There are no air leaks between the AFM and throttle body. 8. I adjusted the TPS per the online TSRM. Here's the issue... The car runs well while cold, but when the car warms up I get what the TSRM calls muffler explosion (not backfire) on deceleration. The car is also very sluggish at normal operating temperature, but it idles without any problems. The TSRM has many possible explanations for this condition. I would like to know what the most likely problem is, so that I don't waste time and money trying to fix.