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Old 11-05-2014
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Location: Fremont, CA
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Engine stumbles at city speeds

OK, '94 2.3l 5 speed stick, no AC with California emissions. So I have this glitchy problem. It only happens after the truck heats up and after a restart. I'm rolling along at about 40 and it's like someone takes ahold of the ignition circuit and flips it on and off about 10 times fast. If I roll up to a stop the engine holds at about 3500 RPMs untill I come to a complete halt, then drops to idle. usually there is a CEL light too. I've replaced everything, I mean EVERYTHING except the ECU. And yes, the ICM is well grounded. HHHEEEEEEELLLP!
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Old 11-06-2014
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Did you check the code.....?
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Old 11-07-2014
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yes, 121 122 224 remeber this is EEC-IV not ODB
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Old 11-08-2014
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EEC--IV is OBD 1, EEC-V(1996 and up) is OBD 2

Codes 121 and 122 both say TPS(throttle position sensor) is having a problem or it's wiring is.
TPS is easy to test with OHM meter and then with Volt meter to see if wiring or sensor is the problem.
If both test fine then Computer is the problem.
Google: test ford TPS

TPS sensor is the same on a 2.3l or 5.0l, it is just a variable resistor, like a volume control or light dimmer

224 is an ICM(ignition control module) fault
Easy to test these as well, many auto parts stores have testers and will test these free of charge.

New parts do not mean "working parts", just FYI, welcome to mass produced cheap parts, lol
This is why it is better to test a part first, confirm it is bad, before replacing with un-tested part, because that is what "new" means now
New = never been tested
We demand cheaper parts, so we are given cheaper parts, they slap a warranty on it and YOU are now the Quality Control department, they happily replace a defective part under warranty but it is a real PITA when you expect it to be working, so you chase your tail for a few hours and then discovery the "new" part is bad, lol.

Last edited by RonD; 11-08-2014 at 05:45 PM.
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Old 11-10-2014
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Join Date: Oct 2013
Location: Fremont, CA
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OK, further observations. I found that my ICM faults out only after heating up and only after a restart. SOOOO if I go out and do the at home ICM test bright and early after an overnight sit, it will test fine. But I noticed that the right bank of the primary coil craps out after warm up and after restart. As an experiment I tried something. I loosened the ICM screws, slipped two hardwood shims under the ICM to create and airspace. I also have a ground wire running from the ground screw to the engine. After a long hot drive the coil is still firing on all cylinders. I realize this is a quick fix for a failing ICM, but it is an interesting experiment eh?

YES I agree with your new parts analogy. and it is indeed exactly my experience with a CKP sensor and a DPFE and an aftermarket ICM (the dying one i have now is a motorcraft one from a wreck) and possibly the TPS that I have now, and a shift position sensor on the Volvo..... come to think of it just about EVERY cut rate piece of **** I buy is exactly that! sigh! live and learn.
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