Missing ?

**97txaggie** · 06-14-2010, 07:16 AM

Okay - if you've seen any of my other posts, you know I've had a tune and still have a miss at WOT. Well, until today. This morning I started the car, let it warm up a little as usual and headed to work. It was missing badly at idle and very low throttle. If I gave it a little gas, it would take off, but as soon as I let off, it would continue missing. It did this for about 20 miles on the way to work, and then ran normal the last 5 miles. I did have suggestions to clean the MAF and check fuel pressure before and I just haven't had a chance to do this since late last week, so I'm wondering if you think this may be related, or if this is leaning more towards Frost's inclination of a bad plug or wire? (This was his thought due to the misfire code being thrown in addition to a knock sensor and O2 sensors)

Any comments appreciated...will try to clean the MAF tonight -- not sure where I'll find a fuel pressure gauge, but I'll keep hitting up my buddies

Thanks,
J

**02Sweet** · 06-14-2010, 07:37 AM

Originally Posted by 97txaggie

Okay - if you've seen any of my other posts, you know I've had a tune and still have a miss at WOT. Well, until today. This morning I started the car, let it warm up a little as usual and headed to work. It was missing badly at idle and very low throttle. If I gave it a little gas, it would take off, but as soon as I let off, it would continue missing. It did this for about 20 miles on the way to work, and then ran normal the last 5 miles. I did have suggestions to clean the MAF and check fuel pressure before and I just haven't had a chance to do this since late last week, so I'm wondering if you think this may be related, or if this is leaning more towards Frost's inclination of a bad plug or wire? (This was his thought due to the misfire code being thrown in addition to a knock sensor and O2 sensors)

Any comments appreciated...will try to clean the MAF tonight -- not sure where I'll find a fuel pressure gauge, but I'll keep hitting up my buddies

Thanks,
J

I would recheck ALL plugs and wires
Clean the maf
buy a cheap FP gauge at a local parts store
report back

**35th-ANV-SS** · 06-14-2010, 08:37 AM

Originally Posted by 02Sweet

I would recheck ALL plugs and wires
Clean the maf
buy a cheap FP gauge at a local parts store
report back

Spot on IMO...and in that order also. Auto parts store sells CRC MAF cleaner. Costs something like $6 a can. You can pick up a cheap fuel pressure gauge I am guessing at somewhere like Harbor Freight.

**jiveass** · 06-14-2010, 09:29 AM

hell, i'd change the fuel filter as well...its only a few bucks and can cause a headache if dirty.

**97txaggie** · 06-17-2010, 03:33 PM

FP = 58-61 or so..pretty darn good...getting ready to clean MAF. Just thought I'd let you all know he used a better scanner this time for me -- showed actual cylinder that misfired -- #3 or 5 had misfired 24000 times!!!! WTH!!!!

All that entire bank had several hundred or more misfires...the other bank was good...mostly zeros, maybe one cylinder had 4....VERY confused!!!

**Cutlass** · 06-17-2010, 06:12 PM

so exactly what codes do you have now? And please list all your mods again to refresh my memory.

**97txaggie** · 06-17-2010, 07:03 PM

0300
0134
0154
0327 and I believe 0507 (high idle i think...) I just cleaned the MAF sensor too -- it was pretty cruddy lookin' and it may have a little more snap off the bottom now, but it still misses...I give up!

Mods -- SLP lid, LTs, ORY, magna flow exhaust.. I think that is it..besides Frost's tune...oh shoot, forgot the LS6 intake...

**Cutlass** · 06-17-2010, 07:17 PM

P0300 Misfire
P0134 HO2S Circuit Insufficient Activity Bank 1 Sensor 1
P0154 HO2S Circuit Insufficient Activity Bank 2 Sensor 1
P0327 Knock Sensor 1 Circuit Low Input (Bank1)
P0507 Idle RPM Higher Than Expected

**97txaggie** · 06-17-2010, 07:27 PM

Yep -- those are the details.. what next ?? Do I move on to the plugs and wires? I already have the plugs and was considering buying the Taylor 10.4 wires - Summit has them for $65 I think.

Any other suggestions greatly appreciated!!

**JayTA98** · 06-17-2010, 07:36 PM

Pull the wires out and check them with an ohmmeter. See if you have an open one. If you have an open wire, then get a new set of wires. Get you a set of tr55's and gap them at 0.050, these plugs are fairly cheap. Try those 2 and see if it gets better. Then if it still misses then go with the next step.

**Cutlass** · 06-18-2010, 05:36 PM

I say for the time being, ignore the other codes and concentrate on the misfire. Plugs and wires are the usual suspects. Since you know what cylinder(s) are missing, focus on those. Check the plugs, wires, check for spark...if thats all ok, we'll move on to vacuum leaks, fuel injectors, or mechanical problems