Hi I have a 97 F-250 7.3L and it has been misfiring at idle and also between 1200 and 1500 rpm. I have an AE it gets a lot of random results on the Contribution test, most times it just fails cylinder 1, then it will fail 1 and 5 a few times then fail 1, 5, and 7 a couple times, and also failed 1, and 8 once. I have done the buzz check it passes every time, and all the injectors sound good. Other weird thing that has happened I unhooked the valve cover harness for cylinder 1 and 3 and i get no check engine light, then i unhooked the harness for 5 and 7 and still no check engine light. Im looking at the IDM since i keep getting random contribution test fails and i don't get a check engine light when the injectors are unhooked. Also both valve cover harnesses are new. Would just like to see if im thinking about this right before i go spend money on an IDM. Thanks in advance.
97 misfire and random cct results
- Thread starter Halex25
- Start date
JD3020
Active member
Have you changed the cam sensor yet?
swapped the idm out today still no luck and checked all the wires again for shorts pin to pin and pin to ground to all the injectors from the IDM connector. With the new IDM installed ran 2 contribution checks got cylinders 1 5 7 the first time and 1 and 5 on the next one.
96F350KID
New member
One do you have a chip installed? IF so remove it and retest. If not what is our ICP reading at idle with how much IPR %?
