knkreb edit: Forum housekeeping: too many folks with same problem in the same thread, getting too confusing. This is Rodd's story with his......

was driving my dads 95 yukon 2wd at about 65mph on the highway and every now and then would get a split second "hickup" where the truck would seem to provide no power to the wheels then re-enguage. pmd was replaced a few months ago (top of the manifold with a heatsink, i'll move it to the bumper when we get some money) and its aparantly been doing this since before he replaced the pmd. any idea what it is? only does this in overdrive.

I just had the same thing happen driving on the fwy at about 70 mph. It cut out and reengaged. I think it might be the fuel filter. I have about 13k on it. Any thoughts?

I will have the hiccup if I run too many tanks of fuel without any additive. I run a mix of the diesel kleen cetane booster and 2cycle oil. It works well for me. I thought I had a filter harness going bad but after a tank with additive I don't have that problem anymore.

I will have the hiccup if I run too many tanks of fuel without any additive. I run a mix of the diesel kleen cetane booster and 2cycle oil. It works well for me. I thought I had a filter harness going bad but after a tank with additive I don't have that problem anymore.

I ran a tank without any addative and fill up yesterday w/ addative. My hicup happened about 75 miles on the tank. It has run fine since.

he runs diesel kleen (both types) in his tank. i should correct my 1st post, i was driving in 2wd but its a 4x4 yukon.

fuel filter was replaced a few hundred miles ago, he runs B20 about every other tank.

b20 will clean everything up in side the fuel system. How long has he been running b20. If he has been doing it just within the last 4-6 months or so then it could have loosened up some crap in the tank.

check lift pump pressure

It's either a weak lift pump, a filter harness, or needs a "feed the beast" mod done. Just the guessings of a former fishbiter.

red sub, I didn't find what year the truck is but you might want to read the link to Heath's blog on "fishbite" http://blog.heathdiesel.com/2005/06/intermittent-fishbite-type-misfire-or.html and see like Veg Out stated if it sounds like your issue. The filter harness killed my "fishbite".

Lift pump test is in FAQ's and is linked to in Diagnostic Checklist sticky.

how do i test his lift pump and what pressure should it be at?

:eek: ... don't let the mod's see that one.... oh my!

May want to consider looking at the recent "snot in my stockings" thread. If your sock clogs up (with running b20) you'd be a candiate for fishbiting. What's your lift pump pressure while going down the road way?

I'm leaning toward optic sensor filter harness myself since we are OBD-I on this one.

KNKREB,
How do you check the optic sensor filter harness? Or what do you check it for?

Quick fire test is to eliminate it. Plug directly in and see if the fishbiting goes away - this will show loose connection end anyway. It does serve a purpose though....

Damn. My freaking truck started cutting out. Driving through a parking lot it died. started right back up and died again. Barely made it home. Died and started right back up quite a few times. I hope it isn't the sock in the tank. I am going to try the filter first and see what happens.

I replaced my filter and drove about 3 miles fine then it started happening again. I guess it is another weekend of repairs.

Quick fire test is to eliminate it. Plug directly in and see if the fishbiting goes away - this will show loose connection end anyway. It does serve a purpose though....

Hi,

If you get same "fishbite" (could also say off/on or misfire?) without Filter harness, a new Filter harness could help? I mean the one I have would not be eliminating that what ever is causing this "feature"?

BR, kane67

Fish-biting can be caused by several things. OBD-I systems with the optical sensor filter harness is one cause, other causes include fuel supply issues, dirty fuel filters, etc, etc.

If you have a suspect filter harness, try pluggin in direct and see what it does. If you end up with the same result, you may want to start looking in other directions.

Thanks,
I plugged direct and have the same (it's very unfrequent).
Anyway, I ordered new cable. I'm trying systematically go through all related parts.
- PMD changed (with cooler in front bumper)
- op sensor changed
- lift pump changed
- wastegate solenoid changed
- all groundings & battery connections cleaned
- fuel filter changed + filter assy cleaned
- TCC solenoid changed
- Using Red Line RL-2 additive (fuel quality is "dry" but very good in Finland)
None of these made any change.

To be changed/checked:
- fuel pump relay + measure voltage pump running
- fuel tank down and check parts there + fuel lines
Well, I need to read more check lists & FAQ's on this site.

BR, kane
p.s sorry I jumped to this topic along with these few questions/comments :o:

Okay I hope I fixed the problem. After reading the Heath blog on fishbyting I decided to swap the PMD with one I had. I let the burb idle for about 10 minutes then drove through traffic for 20 miles and no stall or fish byte. Hopefully that fixed the problem. Time and distance will tell.

Thanks for all the help.