Hbrezzi, will your scanner show the knock sensors?

If so can you monitor how much timing they are pulling from the ignition and when?

Did you look to see what the temperature is that the ECM is getting?

Neal

 

anyone figure this out yet ?

It takes me 1-4 times of disconnecting the battery/ resetting computer for it to run correctly...…..its now screwing up almost every time I drive it.....disconnect battery and back to normal...for a short time

I was getting 6-7 mph at 60 mph this past weekend

 

No, unfortunately it doesnt.

Now, disconnecting the battery doesn’t help me anymore and the overall performance is getting worse.

 

Have you guys had any update or success solving this problem?

 

My issues are still pretty much all there!

Had the exhaust fixed (it had a few cracks before and after the cats that got welded) and it seemed to have improved slightly...

Removed my after market alarm and rewired everything according to original diagrams and, strangely enough, it ran better for about 50 miles with no KS codes but, as soon as I got home, everything was back to square one.

My mechanic is at a total loss. He now thinks that it might be an engine issue and when I asked him what I should try next, his answer was "put it up for sale". I know he was joking and he knows how much I love my truck but, I really do not know what to do!

Just to make sure we are experiencing the same issues: Besides the persistent knock sensors codes, my truck has acceleration issues at low rpms but, at high speed (65+ mph) and high rpms it performs decently. When it is simply horrible is when I accelerate in 3 or 4 gears without kicking it down as it sounds like a boat. If I floor it, it will pick up speed but with some very noticeable of hesitation.

 

Not knowing what else to do, I have just ordered 2 new AC Delco knock sensors.

I now think it is possible that in my previous replacements sensors arrived defective.

And I also asked my mechanic about the 15lbs of torque they need and he said he just tightened them up without measuring the torque... I hope this is the reason why they didn’t work.

Any thoughts?

 

Useless to say that I’m very happy to have woken up from this endless nightmare!

The cause of all my knock sensor issues where the following:

1. Fist I replaced them with cheap non ACDelco sensors.

2. Second time I bought a pair of ACDelco sensors on eBay that ended up being replicas in “original” delco plastic bags.

3. Third time I ordered them again from a reputable website. Again, after only a few miles the codes came back!

4. This time I bought them on Amazon and they looked almost the same as the previous ones but, with better letter engravings and a “made in Mexico” sticker.

5. Last but definitely not least, I bought my mecanic a torque wrench.... yes, he said he had never used one and that, for knock sensors, it wasn’t needed!

6. Cleaned everything thoroughly including the threads were they screw in and torqued them to 15 lbs.

7. As a precaution, built a silicone dam around the rubber plugs and removed the foam in the back.


3 days and my H2 runs like new!!!

As you know I changed almost everything conceivable before finding the culprit but, what the heck, it is now good to go for another 15 years!!

I have to blame my whole ordeal on counterfeit parts and on local labor.

Thanks to every one for their help and, although I could feel stupid for not thinking of this before, I am now an extremely happy camper.

 

That’s great news! I’m happy you found it for the 3rd time I guess?

 

What a relief that first drive must have been. There are tons of fake GM or AC Delco parts out there. AC Delco was one of the first to put a hologram on their boxes in the early 90's to combat counterfeit parts. Even Amazon has some fake parts slip through. Congrats on the nightmare finally being over.

 

Wow - yeah good to hear you finally got it taken care of! I tired generic knock sensors, once. Pulling the entire intake back off to change them made me realize that only AC Delco ones are worth anything but if you get fake ones that truly stinks. What a pain.