92 TC Acceleration

[keygrip]

Hey Everyone, I have a 92 TC Signature w/114k that will not accelerate smoothly. At low RPM's it hesitates and there is a great deal of vibration at the bottom of each gear. It is also especially bad in overdrive when accelerating at highway speeds. At higher rpm's its fine, like if I cruise in 3 on the highway. The engine light never comes on while this is happening. I replaced the plugs about 2 weeks ago and that is the only thing that has been done in the past few months (except oil changes) But it ran fine for at least 10 days before this started happening. Any thoughts on this would be great. :confused: Oh, and one more thing... it gets better when I fill it with super, but it never needed that before.

[bill_s]

First thing to check is the plug connectors - if you have the originals in there (the black plastic kind) they need to be replaced, because they tend to break down and arc in the plug bores. I think the improved Ford connectors are grey. I put an old all-rubber wire set from a '91 Marquis into my 92 TC, which is working OK.

The trouble codes might identify the missing cylinders. If there is a miss at idle, you can pull off the injector connectors one by one until you identify the bad cylinder(s).

In a pinch, to get home, you can try to halve the gap on the plug(s) that are missing to about .025" - this will lower the high voltage and the spark might occurr in the right place. This is better than a missing cylinder, which results in raw gas being pumped through the engine, into the oil, and into the converter, which will get very hot at highway speeds.

Good luck & let us know what the culprit turned out to be....

[TW/92LSC/SE]

If you feel its timing related you might want to make sure the SPOUT Check Connector hasn,t been incorrectly connected or is missing. I don,t think you'll get any Advance without it. (Has someone been messing with your timing?)

[FLM]

From your description, it is high load at lower RPM, including the overdrive at speed. That is a range for plug problems, as cylinder pressures are high in those conditions. Flame front travel and all that. May explain why premium gas helps. Did you replace the plugs with a different brand, type, or construction than what was stock?Sometimes Platinum plugs in particular have caused misfire problems after being in for miles on cars that did not come with platinum. Could always switch to the stock plug to check it out. I have seen this problem myself on a different make of car.

[keygrip]

I did have different plugs in the car but Today I switched the Bosch platnum-2 plugs that I put in before with new Autolite copper plugs and the problem seems to have gotten slightly better, but it is still happening. Especially in overdrive. The wires I have are in good shape and they are the rubber-boot kind. I would have tried the fuel injector trick, but it doesn't seem to miss at idle. I have had the car for about a year and a half and nobody has played with the timing, although it has always pinged a little on steep winding hills (we have a lot of them out here) I may have to take it into the shop tomorrow because I need it on thursday but I appreciate the help guys and I will let you know what it turns out to be.

[bill_s]

BTW, if you still have the original EEC in there, you will find a world of difference if you upgrade this - I dropped a '94 TC EEC into my 92 and the shift behavior improved enormously. For instance, the shift points for 4th gear and lockup moved higher, so the engine doesn't tend to lug as much at part throttle. Best $100 I ever spend in a junkyard.

[keygrip]

The shop said that all that was needed was a new set of wires, they replaced them and everything is fine. The wires that were in there looked pretty new but I guess that doesn't mean much. Thanks again.

[keygrip]

Where is the EEC located in the car? Is it pretty easy to get to or do I have to disassemble the entire dashboard? If the 94 version changes the shift points that would be great.

[bill_s]

EEC is above and a bit to the left of the driver's left foot. You have to pull the plastic underdash cover to see it. Its a silver box about the size of a small cigar box. Its mounted to the firewall, with its connector on the engine side.

Undo the hex bolt on the back of the connector. This will force the connector to disengage from the EEC. This takes quite a few turns. Inside the car, remove the black plastic clip that fastens the EEC to its mounting bracket, and pull the EEC back and out.

Insert the new EEC into the bracket and push its connector through the firewall and replace the black plastic clip, then use the connector bolt to seat the conector. Don't overtighten.

This is all best done in a warm place, because there are almost 60 wires that go into the thing, and the connector is a lot easier to get into position if the wires aren't frozen solid.

You might check with a dealer to get the year or part nbr of the latest computer for your car. I bought the '94 because it was there and cheap. I see no faults in the '94 shift program, so I'm satisfied.