1955 Ford F100

MCB4

New Member
Feb 15, 2019
2
0
1
50
DFW
#1
Got this a this truck a few months back. It has 1993 Mustang cobra motor in it. Once it warms up it starts cutting out almost dies. I’ve replaced the fuel pump, fuel filter, coil, cap/rotor, maf, iac, plugs and wires. Any ideas?
 
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KZGUNS

Active Member
Jul 23, 2018
269
42
38
42
chardon, Ohio
#2
TFI Module? have you checked the codes? could be PIP sensor as well.
 

John Dirks Jr

5 Year Member
Jun 28, 2013
2,173
807
174
54
Maryland
#4
O2 sensors? Because during warm up the system is in open loop and ECU delivers preset parameters for A/F mixture. When the engine warms up the system is supposed to go into closed loop. In closed loop the ECU want's a signal from the O2's for control of A/F mixture.

Check all O2 wiring for damage and good connections at harness plugs. Sometimes its a wiring problem, sometimes the O2 sensors themselves go bad. I had a rodent, probably a chipmunk bite my O2 wire in half. Threw a code, ran bad. I discovered the damage and spliced the wire to repair.
 

90sickfox

I didn't really have an issue with the stink...
SN Certified Technician
Mar 2, 2015
4,100
3,419
183
41
#5
+1 on o2 sensor or harness. Another issue could be the intake air temperature sensor. It should be in the drivers side of the lower intake kind of under the upper plenum. The single wire sensor is the gauge temp sensor. The other sensor threaded into lower intake is the IAT sensor.
 
Feb 18, 2001
29,770
6,330
224
Massachusetts
#6
How was the conversion done? What ECU is the engine running? There's a 3-digit code on the ECU and the cobra motor requires a specific ECU. Is it a true cobra motor or an explorer/ho motor with a cobra intake?

Is factory wiring harness being used or is it a custom aftermarket harness?

Able to dump engine codes?
 
Jan 10, 2011
130
6
18
#7
If it's got a fox body style harness and EEC, you should be able to pull codes without a code reader. It'll need to be at operating temperature and in neutral. Jumper the connector, or attach a test light, then key on & count flashes.

There are instructions all over the place to go with. It's real easy. I do mine every so often, just to keep an eye on things. Not all codes will set a check engine light, lot of times I've pulled codes and found a potential issue that would've gotten much worse with time.