1997 SRW crew, 5.8 ZF5. Still playing with this project. Each time I fix something it gets a bit better but I'm still chasing a intermittent engine shake. Worked through the normal things, confident in vacuum, fuel pressure, EGR, O2 sensor, TAB TAD plumbing, IAC, throttle body, I have a correct idle RPM but a shake comes and goes and consistent shake around 1500 accelerating, smooth as silk decelerating. The computers temp sensor is new, air temp sensor new, TPS meters healthy. I have isolated the fan clutch and shake is still there. Determined one of the driveshaft pieces was bent early on and had the bent one retubed, both balanced, all new u joints and hardware. Plugs and wires and wire routing are recent/correct. Still have a compression check to do


but the motor is able to run smooth just not consistently smooth.


So I pulled the computer to look there. No signs of capacitor leaks or bad solders. The capacitors are brown, not the blue that seem to be the color talked about when leakage is seen.

I know for certain the driver's door is at least the second door on the truck because I put it there, possibly the 3rd. I cannot find the stickers for the life of me, I'm assuming they went with the original door or should they have been on the pillar behind the door on a crew like on a extended or standard can??. Trying to find the calibration code.

Please see the pictures of the computer. Is IRE1 the code? It's in two places.

also, should I replace the capacitors while it's out just as a good measure? They appear prestine.

As always thanks for any insight.

 

Sorry for the images in the middle of the thread above. I guess I lost track of my curser.

 

Age of O2 sensor? Any stored codes?

Cap and rotor clean, no carbon buildup?

 

O2 sensor is less than a year old. Plugs, wires, cap, rotor about 14 months old.
That doesn't necessarily mean all is well with any of that though.

Thanks

 

if your sitting still, can you give it gas up to 1500 and see if the miss is there, or you think its more shake, than miss, might help determine

 

It's engine, shake/vibration in the same RPM range sitting still or rolling. Clutch in clutch out. Speed doesn't matter.

Thanks for the ideas on the vibration. Does anyone have knowledge on the calibration code question.

Thanks

 

The numbers seem to match on Rock Auto. Third one dowm. Sandy

 

Without the CALIB CODE, you are going to have a time finding correct system replacement parts.

Are you using a scan tool?

 

How are the engine and trans mounts?

 

the IRE1 is not your calibration code, but going by the F6TF-12A650-BJB, like Sandy said, Rock Auto had/has that one, Oreilly Auto also has it, but not that you should buy it, until you prove more thoroughly, that PCM is causing issues, have you checked your harmonic balancer, if it has spun/moved any could cause it, I just changed mine when I did water pump/timing gaskets, and my timing was off 4-5*, of me thinking 12* it was 7*, and had what I called a hard idle, not really a miss

 

All three mounts are new.

​I've looked at the balanced and all seems well. Appears intact and the marks come up where they are expected to.

Thanks
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Does it happen at idle? Perhaps harmonic balancer is faulty?

 

Have you tried to align timing marks @ #1 TDC with a piston stop? May be the balancer outer ring slipping.

 

Does it matter what gear you are in?

Edit: Never mind. If it's sitting or rolling and clutch in clutch out. I wasn't thinking straight.

 

Just to give the thread some closure the harmonic balancer is good. Still searching.