97 Chevy s10 miss under load

[metalman55]

Originally Posted by old_master

If a DTC comes right back after clearing them, the problem is not fixed. DTC's never tell you that a part is faulty, they tell you what circuit a problem has occured in. Find out what the DTC was, then post it here and we can diagnose the problem.

alright, i got the code checked again. it is P1336

[old_master]

P1336 "Crankshaft position system variation not learned" must be performed with a bi-directional scan tool. The run of the mill scan tool is not capable of performing the relearn on the 2.2L engine. I can email you the procedure if you need it, but most shops will have it.

[metalman55]

Originally Posted by old_master

P1336 "Crankshaft position system variation not learned" must be performed with a bi-directional scan tool. The run of the mill scan tool is not capable of performing the relearn on the 2.2L engine. I can email you the procedure if you need it, but most shops will have it.

alright, doesnt sound like theres a way around takin it into a shop for that. what do you think my chances are of this fixing the hesitation/backfire problem? any other ideas about that?

[old_master]

If there are any other DTC's, other than the P1336, they must be diagnosed and repaired BEFORE doing the relearn. Did you do all of the steps, in order, in post #4.

[metalman55]

Originally Posted by old_master

If there are any other DTC's, other than the P1336, they must be diagnosed and repaired BEFORE doing the relearn. Did you do all of the steps, in order, in post #4.

no other codes that the guy from autozone told me. i did do the tests. it wasnt missing but i did them anyways. switching the plugs it still worked fine, switching the wires on the plugs made it idle horribly but i dont think any other codes came up (last time a code came up while there was already one the ses blinked and it didnt this time). i didnt get a chance to change the wires on the coil pack yet.

im taking it to a shop monday to have the relearn procedure done, then it sounds like ill have to drive it around for a week or 2 unitl it learns it. its a different guy from the first time and he has way more equiptment and better code readers so i might bring it back for a couple hours of diagnosis but he was sayin that he wouldnt let me have him diagnose it than me work on it more so im probly gunnu have to pay the guy an arm and a leg. anyways, ill keep the page updated.

[old_master]

Originally Posted by metalman55

....switching the wires on the plugs made it idle horribly....

The reason it idled horribly is because you had the plug wires crossed. You need to swap entire plug wires from cylinder #1 & #2, not just at the spark plug end. If P0302 is set, the wire that is on cylinder #2 is faulty. If the P0301 still sets, move on and do the coil test.

Originally Posted by metalman55

....im taking it to a shop monday to have the relearn procedure done, then it sounds like ill have to drive it around for a week or 2 unitl it learns it....

When the relearn procedure is performed correctly with a scan tool, the relearn is done immediately. Don't let him buffalo you into thinking you have to drive it around for the ECM learn it. That's the reason for the procedure, to force the ECM to relearn.

[metalman55]

okay, so the solution was found by the mechanic. i probly wont be taking anything back to him though. apparently it took him 6.5 hours and an expensive phone call to fix it. he wasnt very clear on what the problem was exactly but im pretty sure he said one of the coil packs was slowly failing. what really sucks is that was the next thing i was goingto change. he also put a used pack in and never called to check if i wanted him to put a new one in. i probly would have had him replace both of them with new ones, but oh well.

all in all, i would have been able to fix it sooner thanks to the help here if it was giving me a missfire code to do the tests with. or if i changed the coil packs instead of the cps (still frusterated that my hanes manual says nothing about a relearn procedure). but the truck now runs smoother and stronger than it has in a long time! thanks for the help and info master

[old_master]

Wow! One more step and you would have found it. Oh well, glad you got her fixed.

[shaunst]

I have a 1999 S-10 2.2L 5M with a similar problem. I recently bought the truck with no apparent problems. It has 125,000 miles, so i decided to change out plugs, fuel and air filters. After doing that and sitting in line to get emissions done CEL came on, code was P0301. Checked plugs and wire connections, reset computer, same code in about the same amount of time. I swapped plug wire #1 and #2, reset computer and P0301 came on again. Next step i was going to swap the coils around but i read in here how you suggested just swapping #1 and #4 at the coil. Will this also work in the 1999 (i'm thinking it will). Thanks for any help.

[old_master]

Swapping 1 and 4 at the coil will work on 99 as well. The only thing you have determined so far is that both wires are good. You'll have to do the ENTIRE procedure EXACTLY as outlined in post #4 to determine what's causing the misfire. You're using the ECM to pinpoint the problem by giving it good information in different places. Depending on where you put the "known good" information and the ECM's reaction, the cause can be determined. There are several things that can cause the problem you're looking for: spark plug, plug wire, ignition coil, injector, ECM and/or injector wiring. You "force" the information where you want it, the ECM gives you a result.

[shaunst]

I've also switched the plugs, so the next step would be the coils. Thanks i'll give that a try tonight.

[old_master]

Only at the ignition coil, (not the spark plugs) swap #1 & #4 plug wires. If the miss moves to cylinder #4, the coil is faulty.

If the miss stays on cylinder #1, the problem is with either the injector, the wire harness to the injector, or the ECM.

[shaunst]

swapped #1 and #4 at the coil. Reset computer, and after about 20 min of city driving code came back on P0301. So looks like the injector is next.

[old_master]

Could be a partially clogged injector, a faulty injector, a poor connection between ECM and injector, or a poor or loose connection in B+ (pink) wire to the injector. It could also be a vacuum leak to #1 cyl only, or a mechanical problem in the valve train.

[shaunst]

Well the injectors are impossible to get to. They don't look to be as easy to access as the earlier design of the intake manifold on the 2.2L. Do you have a break down on diagnosing the other things you said could be wrong? I'm trying to do the easiest first.