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Topic: My TC is missing & bucks while accelerating when cold. Works perfect when hot  (Read 2126 times) previous topic - next topic

My TC is missing & bucks while accelerating when cold. Works perfect when hot

My 88 T-bird Turbo Coupe starts and idles fine, but when driving while it's cold, the car starts to buck and miss until it worms up. Then it runs great when wormed up.

I have replaced the following: 
New plugs and wires, new Idle Control Air (ICA), clean throttle body, Distributor cap & rotor, and the Fuel Pump & filter. Could it be the TFI module or the distributer pick up? What am I missing?
 
Any help with this annoying problem would be greatly appreciated. 

Thanks,
Victor Stone

Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #1
Codes?

Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #2
What brand of plugs and wires plus what did you gap them to?
1988 Thunderbird TC, 5spd
Stinger 3" single exhaust, Cone Filter, Adjustable Cam Pulley, Schneider roller cam,
'93 Mustang Cobra replica wheels on 235/50R17

'16 F150 XLT 5.0
'17 Husqvarna TX300

Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #3
ECT sensor out of range?
Long live the 4-eyes!  - '83 Tbird Turbo

Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #4
Now there's something. 
Open circuit, the reading of Ford thermistor sensors is -40F.  At that temp, the EEC will practically be DUMPING fuel cold start enrichment trying to warm up.  On the other hand, a failed open ECT, usually doesn't change it mind, so either warming up improves it's ability to burn the extra fuel, or fueling isn't the issue.  Fueling related concerns are usually smoke, or lack of power depending which side of stoich you're stuck on. 
EGR is inert, so a leaking EGR valve causes all sorts of misery, but not usually harsh misfire, because fueling issue.   Harsh misfire is usually the domain of the ignition system.  By the sound of things, though, you've got most of that covered.  As most of us know, TFI issues get worse with heat, not better, so probably not TFI.  The PiP in the distributor could do it, but that's not really an everyday kind of failure.
Questions:
how's the gap and heat range on those plugs? 
Mods? specifically boost mods?
Can your coil jump a 15kV (25kV with big boost) or larger gap on a spark tester?
Fuel quality? Octane?
How's the weather where you are?
What brand of parts did you use in your Ignition System?
Cam timing?
Hydrocarbon leakage from chamber to Cooling system (AKA failed headgasket)?


Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #6
I purchased the car with this issue. I'm trying to resolve it and have made the aforementioned repairs and the issue is still not resolved. Although the tune up certainly improved the performance. But when cold it still bucks and misses. :mad:  :yuck:
Victor Stone

Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #7
What brand of plugs and wires plus what did you gap them to?
all parts were replaced with Motorcraft. 
Good!
What did you gap the plugs at?  Should be around .028"
From there I would follow TheFoeYouKnow's list
1988 Thunderbird TC, 5spd
Stinger 3" single exhaust, Cone Filter, Adjustable Cam Pulley, Schneider roller cam,
'93 Mustang Cobra replica wheels on 235/50R17

'16 F150 XLT 5.0
'17 Husqvarna TX300

Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #8
Plugs were gapped at .028” exactly. Although @TheFoeYouKnow has a good point about the ECT bcus my temperature gauge is not working at all. 
Thanks everyone, I’ll look into the ECT and I’ll keep you posted.
Victor
Victor Stone


Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #10
There is a code for temp sensor out of specs.

Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #11
So I looked into the temperature gauge and what's happening is that the gauge stays on the cold (C) position even after driving it for over 1/2 hour around town. With the engine hot the gauge still stays on 'C'. I turn on the heat all the way to high and the gauge goes slightly over the 'C' but no more than that where it should float in the 'normal' range. I also noticed the blower blows cold air and no heat. I'm thinking the thermostat is bad and needs replacing. As for the ECT sensor, I am still trying to locate it's position.  :mad:  :yuck:  :dunno:
Victor Stone

Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #12
If you are going to replace your thermostat I suggest a Stant "SuperStat" 192°.  Some of the other brands have been questionable in operation including the subbed out Motorcraft.
1988 Thunderbird TC, 5spd
Stinger 3" single exhaust, Cone Filter, Adjustable Cam Pulley, Schneider roller cam,
'93 Mustang Cobra replica wheels on 235/50R17

'16 F150 XLT 5.0
'17 Husqvarna TX300

 

Re: My TC is missing & bucks while accelerating when cold. Works perfect when hot

Reply #14
Have you replaced the fuel filter by chance? I would check the catconverter if you have one, I have seen this before. Disregard if this isn't of use just a little input from experience. Good luck.