My 88 TC has been running fine for the 2.5 years that I have owned it. I have put on about 25,000 miles without doing a tune up and I don't know when it was last tuned. I decided to install new cap, rotor, wires and plugs. I used Motorcraft parts and #764 plugs gapped at .032" and checked the timing which is at 10 degrees. Beginning at the moment I started it following the tuneup, it runs very poorly. Either it dies trying to idle or idles at 1500 RPM. I have gone back through everything and redone the whole job with no improvement. I have gone through the TPS adjustment which was very difficult because it wouldn't idle with the IAC disconnected unless I set the idle stop to almost 1500 RPM. Even then the idle would wander around between 900 and 1500, and this is with the IAC disconnected. When it does idle it will ocassionaly sputter out the exhaust which it never did previously. The TPS does have an interuption when going through it's travel range at around 4 volts. I pulled codes and got a 73 and 76, KOER. I don't have my code list here but as I remember 73 has something to do with incorrect TPS and VAM readouts. I did open the throttle at the appropriate time during the test. Code 76 is oxygen sensor staying lean. Anyone have any input?
73 = throttle didn't open far enought and 76 is the VAM didn't open far enough during the dynamic response portion of the test
Try putting the old cap, rotor, and plug wires on, and see if it goes back to normal. If it does, start putting the new parts back on until you find the problem. Are you sure plug wires are fully seated on the plugs and dist cap terminals?
------------------
Jeff Korn
88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 21 psi, forced air intercooler, water injection, bypass valve, Ranger roller cam, subframes, etc., etc.. // 86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP nitrous, ignition, gears, suspension, etc., etc.... // 91 Escort: Bone stock winter car // 02 Taurus Vulcan(wifes car)
When I was putting everything back together a couple weeks ago I realized that as I was putting on the spark plug wires, the connector in the boot that goes on the plug would push back in the boot to the point it would not be on the plug even when the boot was completely covering the plug.
It was a PITA to try and push the wire back into the boot, so I trimmed about an inch or so off the end. It was enough to let me be sure I got the snap sound of a good connection, but not too much to leave alot of the plug exposed.
Just a thought.
Maybe you loosened a hose clamp on the throttle body or turbo sides of the hoses to get the intercooler off and forgot to tighten those clamps back up? Make sure the vacuum lines are reconnected to the intercooler also.
Quote:Originally posted by Kev:
Maybe you loosened a hose clamp on the throttle body or turbo sides of the hoses to get the intercooler off and forgot to tighten those clamps back up? Make sure the vacuum lines are reconnected to the intercooler also.
I agree with Kev, because it happened to me twice. Check the lower (turbo to intercooler) hose on the intercooler. Any small leak here will give you a fit.
------------------
Dan S
NATO Member
84 and 88 Turbo Coupes
It's no longer a hobby, now it's an osbession!
Thanks for the replies. I did go over everything and verify that all wires were seated properly and I also checked the intercooler hoses. In fact the hoses were the first thing I suspected. I will though, go back and triple check before I start re-installing old parts, which was going to be my next step anyway. Pete, I may not have remembered the code numbers correctly as they are written down at home and I am at work. I do though remember that one of them was, oxygen sensor always lean. It seems like I've done a thousand tune-ups in my 34 years of driving, but this is a first for me.
From the $.02 department....
Uh I didnt see it noted, but the timing was set with the jumper out right ?
Yes, the timing was set with the Spout out. Thanks anyway.