Missing, what to check now?
Thread Starter
Teching In
Joined: Mar 2003
Posts: 35
Likes: 0
From: Denver metro area
Missing, what to check now? Hi guys... I don't post much, but I'm always glad that there's a place like here to come for smart people. My car is missing like mad. It misses a little on all cylinders, but it misses terribly on the #1 and #6.
I have a cam (I'm sorry, I don't have the specs for it), and some head work done as well.
I have no real history on this motor. It was replaced by a shop. Less than satisfactory job, but a long story and I'm stuck with it so this is what I have to work with.
I replaced the plugs and wires on all 8. MSD wires and TR55 plugs. I also replaced the coil packs for the two that are missing most.
I haven't had it on a computer to see the misses per cycle, but I know it's still has to be high (I reset the SES on a P0300 8 times on a 300 mile drive).
Prior to the plugs and wires, it would fire some, but miss more often than fire.
The plugs that were taken out looked to be in different shape, though the #6 was actually a stock plug. I forget what the others were for certain, but someone said it's a plug usually used with NOS.
What else can I get ya and what should I check?
Thanks!
I have a cam (I'm sorry, I don't have the specs for it), and some head work done as well.
I have no real history on this motor. It was replaced by a shop. Less than satisfactory job, but a long story and I'm stuck with it so this is what I have to work with.
I replaced the plugs and wires on all 8. MSD wires and TR55 plugs. I also replaced the coil packs for the two that are missing most.
I haven't had it on a computer to see the misses per cycle, but I know it's still has to be high (I reset the SES on a P0300 8 times on a 300 mile drive).
Prior to the plugs and wires, it would fire some, but miss more often than fire.
The plugs that were taken out looked to be in different shape, though the #6 was actually a stock plug. I forget what the others were for certain, but someone said it's a plug usually used with NOS.
What else can I get ya and what should I check?
Thanks!
If you have HPTuners, do a 'crank relearn'.
Last week I had over 127 misfires on cylinders 1 and 6, the rest were in the sub 20 range. PO300 every drive, even flashed on me a couple times (SES). I did the same, replaced the plug, wire, swapped coil packs and injectors.
Did the relearn, now all cylinders are fine.
If you don't have it or know someone with it, a dealer can do it with a Tech II for a one hour charge ($65-$85 depending on what part of the country you are in).
Last week I had over 127 misfires on cylinders 1 and 6, the rest were in the sub 20 range. PO300 every drive, even flashed on me a couple times (SES). I did the same, replaced the plug, wire, swapped coil packs and injectors.
Did the relearn, now all cylinders are fine.
If you don't have it or know someone with it, a dealer can do it with a Tech II for a one hour charge ($65-$85 depending on what part of the country you are in).
Hmm, I have the P0300 codes going on an off all the time but it missfires nearly every time I drive it, I have HPtuners but what is "crank relearn" and how do I do it? Can this cause anything negative to happen?
Thanks, MAtt
Thanks, MAtt
No, it just lets the PCM relearn the crank.
The test involves running the car up to 4K, all of a 10 second test.
Use the scanner, connect to the car.
Go to DISPLAY, VCM controls.
Go to the SPECIAL tab.
Hit CASE learn.
Follow the instructions.
The test involves running the car up to 4K, all of a 10 second test.
Use the scanner, connect to the car.
Go to DISPLAY, VCM controls.
Go to the SPECIAL tab.
Hit CASE learn.
Follow the instructions.
Last edited by Viper; Aug 29, 2006 at 03:06 PM.
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Thread Starter
Teching In
Joined: Mar 2003
Posts: 35
Likes: 0
From: Denver metro area
Interesting... I have a friend with an HP tuner, I'll have to try to get him to do that.
By the way, some others were concerned that perhaps there was no compression, so after locating a compression gauge, I tested the worst one and the easiest to get to (#1) and it was up around 148psi. That's pretty good right?
If this crank relearn thing doesn't work, do you have any other ideas?
By the way, some others were concerned that perhaps there was no compression, so after locating a compression gauge, I tested the worst one and the easiest to get to (#1) and it was up around 148psi. That's pretty good right?
If this crank relearn thing doesn't work, do you have any other ideas?
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