pathfounder

Now I REALLY think it's the MAF...

I had a faulty MAF that caused similar problems. Mine is an auto, so when the transmission shifted up, I would have to give it more (or sometimes less) gas to maintain speed. This is because the air flow would be changing significantly when the engine's speed changes, and the MAF's improper signals would cause problems.

I have a 98 in a 97 and it fit properly. There WAS a change with the axles (spline count, maybe more). The change date is grey, but I think it is after 1999.5. I realize this answer doesn't help much.

You can relocate it by chopping the wires right after the right-side valve cover connector and wiring it to a new KS that you bolt to the top of the intake. It works, but it should be obvious that it's not as good at picking up knock signals as it would be down low in the V where it belongs. Do a Google search for "knock sensor relocation" and you'll get a ton of results, including part numbers.

If you pull the engine out of the truck completely, you could reach into the "V" of the engine and change it without removing any part of the intake. If you don't want to pull the engine (and who could blame you), then no, ALL of that crap needs to come off. We have arrived at why people often relocate the KS to the top of the intake.

Replacing the knock sensor is a very big pain. The engine has many coolant and fuel hoses. Most of them cracked or failed when I unclamped them. The basic steps are: -Remove the fuel pump relay and crank the engine many times until it won't run at all. -Drain coolant, down to below cylinder head deck level at the very least. -Remove upper intake -Remove lower intake. This requires disconnecting the fuel system, which is what step 1 was for. -Replace the KS (takes about 2 seconds). You will need new intake gaskets at the very least, and be prepared to replace a ton of hoses during the process. The new KS gave me 18MPG instead of 14 on the highway, so it was worth it. As for the idle, I forgot to reconnect the idle solenoid when I re-installed the upper intake, so now it is stuck on the highest idle. I shimmed the solenoid to override it. I will probably regret this in the winter.

To follow up on this thread, the knocking was because the ECU reset itself because it had no power for over 24hrs. I did the colossal knock sensor replacement job, and now the truck runs like a dream.

I reconnected all vacuum lines, but yes, I should check. The problem with setting the timing is the design of the VG33 balancer is such that when the rubber part of it slips, which happened to me when taking it off the crank, the timing notches become meaningless. It would be nearly impossible to re-index it accurately. I'd have to just buy a new one.

The water pump was dying, so I replaced it. I did the timing belt as well (may as well, it has to come off anyways). I was VERY careful to line everything up when doing the timing belt. The cam sprockets and crank sprockets were all lined up dot-to-dot and the lines on the timing belt also lined up perfectly. I can't begin to fathom that I did it wrong. Anyways, on first key after the big job, the engine started up and seemed lively. I noticed that it idled at around 1800rpm instead of around 1100 like usual. The RPM is always a bit high at idle now, not bad but noticeable. Being an automatic, it affects creep and downshift smoothness a bit when dropping to first for a red light. It drives well and the power seems exactly the same. The water pump noises are now gone obviously. I would almost think the knocking was always there and hidden by the pump noise, but the high idle makes me think there's an issue with the ECU or something. Note that I can't set the timing absolutely because the balancer collar slipped, but I can tweak it slightly one way or the other. Any ideas guys?