North American Turbocoupe Organization



88 TC Stumble/Miss
TurboTim88 Offline
Junior Member
#1
Hey have not posted in quite awhile. My TC has developed a stumble/miss/hesitation. From the reading I've done my symptoms are similar to the TFI/PIP issues that have been discussed on the board. However, I only experience the problems when the engine is cold. My car has a bit of an erratic idle and when accelerating the car will stumble and hesitate. It has never completely stalled though. After driving a few miles and once the car is warmed up, the engine runs fine and the stumble/miss goes away. Would this still be a symptom of the TFI/PIP sensors? Or is there something else I should be looking at? So far I have swapped Vane Air Boxes, checked the fuel pressure, and had the fuel injectors cleaned. All have not done any good regarding this problem. Thanks for the advice.
1988 Ford Thunderbird Turbo Coupe Pretty much stock K&N filter and 2.5" dual exhaust
2000 Ford F-250 XLT Superduty diesel 4x4
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natmac3 Offline
Administrator
#2
I would check for codes before continuing, if you haven't already. If all sensors check out okay, then check compression and run a leak-down test to make sure everything's sealing properly.

--n8
1987tc
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Jeff K Offline
Administrator
#3
TFI/PIP problems usually rear their ugly head when they heat up, but I have heard of a few cases of either or both causing problems when cold only.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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TurboTim88 Offline
Junior Member
#4
Hi Guys... thanks for the replies. I was able to run the codes on the car tonight. Here are the continuous memory codes it had:

41, 65, and 72

I cleared the codes and took the car for a little drive and it was still stumbling. When I got back I ran the key off diagnostic again. I get a code 11 during the first part of the test, and then get the same 41, 65, and 72 codes in continuous memory. Anyone have any advice on where I should go from here?
1988 Ford Thunderbird Turbo Coupe Pretty much stock K&N filter and 2.5" dual exhaust
2000 Ford F-250 XLT Superduty diesel 4x4
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Stan B. Offline
Member
#5
Code 41 is system always lean code 65 is Electrical charging over voltage and code 72 is no map change in "goose test" hope this helps.
88 Turbocoupe(maroon)Stock
96 gt mustang...CAI,Trickflow plenum,H-pipe,flowmasters,UDP,70mmTB,3.55gear
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Jeff K Offline
Administrator
#6
CM 41 is "O2 indicated lean for 15 sec when closed loop operation was expected." This does NOT mean for sure that the motor is running lean. It means that the PCM thought the motor was running lean based on O2 input, and tried to richen it up to compensate, but reached the end of its ability to compensate (LTFT railed out). CM 41/42 are symptom codes, and can be caused by O2 problems, harness problems like orange O2 ground not connected, TPS and VAF problems, fuel pressure problems, etc.

Code 72 is NOT "no MAP change detected during goose test", since our cars dont have a MAP sensor (they have a BARO sensor). If I recall correctly CM 72 is a power momentarily interupeted to PCM when a power interupt wasnt expected. There was a long winded discussion on this code a few years back, but I dont recall any definite conclusions were reached.

Dont recall what a CM 65 is off the top of my head, but I seem to remember it is a sensor undervolt code.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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JT Offline
Posting Freak
#7
Code 41 along with code 65 would point to a possible o2 sensor or circuit issue. Code 65 indicates the system never went to closed loop mode.

Quote:Originally posted by Jeff K:
CM 41 is "O2 indicated lean for 15 sec when closed loop operation was expected." This does NOT mean for sure that the motor is running lean. It means that the PCM thought the motor was running lean based on O2 input, and tried to richen it up to compensate, but reached the end of its ability to compensate (LTFT railed out). CM 41/42 are symptom codes, and can be caused by O2 problems, harness problems like orange O2 ground not connected, TPS and VAF problems, fuel pressure problems, etc.

Code 72 is NOT "no MAP change detected during goose test", since our cars dont have a MAP sensor (they have a BARO sensor). If I recall correctly CM 72 is a power momentarily interupeted to PCM when a power interupt wasnt expected. There was a long winded discussion on this code a few years back, but I dont recall any definite conclusions were reached.

Dont recall what a CM 65 is off the top of my head, but I seem to remember it is a sensor undervolt code.
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Stan B. Offline
Member
#8
I am sitting here looking at a computer printout
of all the codes listed for a 88 tc.I got them off of Alldata from my shop.I know our cars dont have an map sensor.Thats just what it says,wether it applys to a praticular car or not.
Code 65 says charging over voltage.Just trying to help Geeeeeeez!
88 Turbocoupe(maroon)Stock
96 gt mustang...CAI,Trickflow plenum,H-pipe,flowmasters,UDP,70mmTB,3.55gear
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JT Offline
Posting Freak
#9
Quote:Originally posted by Stan B.:
I am sitting here looking at a computer printout
of all the codes listed for a 88 tc.I got them off of Alldata from my shop.I know our cars dont have an map sensor.Thats just what it says,wether it applys to a praticular car or not.
Code 65 says charging over voltage.Just trying to help Geeeeeeez!
Some EECs do have codes that are specific to them. Even the NATO site here has a few codes wrong. Code 65 is one of them that NATO, and your readings, are wrong on. I'm using Ford documents, along with some experience in this area. Code 65 is that the TC EEC didn't go to closed loop mode. This means the oxygen sensor and circuit should be reviewed.
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Jeff K Offline
Administrator
#10
Alldata wrong?? What a shock.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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