[JesseB]

Hey guys, I recently had a 6 hour road
trip where I filled up at different gas stations as normal. I was wondering if bad gas could cause multiple random misfire codes (300s)? What happens is, I can start my car and it will be completely fine, I will take off and it could be a mile down the road or 15 (completely random) and the car will lose power, check engine light will blink and the car will idle very rough. I pull over, turn the car off, turn it back on, and it's completely fine...I just realized yesterday, when it happened, I just put it in neutral and was about
To pull over and the light stopped blinking and I put
It back in gear and it was completely fine (did not need to turn car
Off) ...the first time it happened it threw codes 626 and 264 (along with the misfire codes) ...it has not thrown those two since the first time (I did have to change a headlight, not sure if that was related), I believe one is a high volt
Code and one is a low voltage code, eitherway, this has not happened again, but the misfires codes happen about once a trip...any ideas?

 

[rob the elder]

Check the engine ground. It might be an intermittent loss of ground. Check the left front of the motor. There are multiple threads on this subject.

 

[JesseB]

Ok, thank you rob! Figured asking questions, even if already asked helps keep the forum alive...I did see the thread where the engine ground was a possible cause (I believe it ended up being a failed cylinder) and I saw the link for the grounds, just posting to see if any others have had this and maybe more solutions...can you explain to me what im looking for and how to ground it better if it is ungrounded....hopefully this is an easy DIY...thanks again for the help! -Jesse B

See Fly's note. The ground material has been known to corrod and lose connectivity. Treat it like a battery terminal, pull it off, inspect, clean and apply dielectric grease to assure good contact.

 

[llllfly]

Take the cover off the engine by pulling it up
like Rob stated. Looking at the front driver side
one bolt your see the G wire's.
Make sure that bolt is tight.
LLLFLY

 

[JesseB]

Bolt was completely tight...the car had been doing better, happened only once after a fill up at my regular gas station. Now im around 60 miles left on my gas tank and its happening again...I was reading and saw that a member had close to the same problems and had loose wire harness at high pressure fuel pump solenoid, could this be a possibility? If so, is this easy to check? Also, along with the multiple random misfires and a misfire for each cylinder, the P0264 came up again (Cylinder #2 Injector Circuit Low)

I have autolite iridium plugs in my car, and although they have very few miles on them, I did have to gap them (I have heard some people say you should NOT gap iridium plugs, but they were way off) ...although I figured if it was the plugs, it would have happened earlier, they have 2 or 3 oil changes worth on them....

Also, I have the K&N Typhoon intake, and was wondering if a dirty/oily MAF could cause these, if so, is it easy to check and can you instruct me on how to check it.

Thanks for all the help guys!

 

[Seltzinator]

Just because the bolt is tight does not mean that the ground is good. Remove the bolt and check for corrosion. If there's corrosion, get a wire brush and polish it off. Either way, slap some dieletric grease in there before re-attaching.

 

[LatinVenom]

The K&N has been problematic to other people. Also go back to the original OEM 41-108 delco plugs and gap to 32.

 

[JesseB]

41-108s are on their way to my home...just saw robs edit on my post and seltzinators advice, I will take the bolt off and check...I would guess this is not the case because
I just had my head gasket replaced a couple months back and would think that it would have been cleaned when putting back together

Is the MAF sensor the electrical plug that goes into my CAI? What do I look for on it and how do I go about cleaning it?

 

[JesseB]

Also wondering if a bad coil pack on #2 could cause the P0264 (Cylinder #2 Injector Circuit Low) ...When my spark plugs get here, I will switch coil packs #1 and #2 ...to see if it later throws a code for Cylinder #1 injector circuit low...that would seem to narrow it down

 

[LatinVenom]

Yes the wire that plugs into the CAI is for the MAF.
Just unbolted and inspect the MAF.
Get some MAF cleaner at an autoparts store.

 

[Bills86e]

Use good tools:
1. Actron CP9550 OBD-II Code reader/erase
2. MaxiDAS DS708 Automotive Diagnostic System
3. Power Probe Master Diagnostic Pack w/the HOOK, Power Probe III kit, & PPCT #PPDP1Power

 

[rob the elder]

You are doing the right things.

Generally what you want to do is eliminate all the easy things and if that does not address the problem, move on to the more difficult things.

Intermittent issues can easily be caused by ground issues, loose wiring, ignition parts that have not yet failed hard but are marginal.

Generally start with eliminating the path to ground. Check the battery terminals. If your battery is over 4 years old, load test it. Check the engine ground by removing it, visually inspecting the condition of the mating surfaces. Frequently the connection looks fine until you pull it apart and many have found a layer of rust or junk under there that is actually causing problems. Clean it and put a layer of conductive electrical grease on both mating surfaces and over the replaced joint.

Some have experienced intermittent issues found to be the connectors to one or more of the coil packs.

The fact that the head has been off recently suggests that verification of all the electrical connections on the top of the motor is in order. I would verify that they are all clean and well mated.

Generally a MAF contamination issue will not be intermittent. It will throw a code and you will know its upset or it will not. But there is plenty of evidence that MAF issues are both easy to occur from multiple sources and easy to address. I would pull it out, visually inspect it and clean it well using MAF cleaner. Its easy to do, only takes a few minutes and worth learning how to do.

I went to a K&N filter on one of our kappa's but after reading of all the issues people were having, and learning that they offered zero performance improvement I decided to eliminate that as a potential issue and went back to the stock paper filter. I have not regretted that decision.

The more difficult things that can cause problems like yours are related to coil packs, spark plugs, fuel delivery issues related to an injector etc.

Are you using the fuel treatment to prevent issues with the fuel pickup and gauge in tank hardware?

 

[WWI Flying Ace]

How many miles on the car? I had a long odyssey with an intermittent power loss/CEL issue that turned out to be a different cause. Not trying to distract you from the excellent advice given here but the things you described were what I was seeing too, even though the codes were different. Mine turned out to be a valve issue.

http://www.solsticeforum.com/forum/f63/gmpp-tune-p0101-code-56557/index16.html#post1095414

"#PIPS029: Engine Misfires Due To Major Carbon Deposits On
The Intake And/Or Exhaust Valves - (May 29, 2012)
Subject: Engine Misfires Due To Major Carbon Deposits On The Intake And/Or Exhaust
Valves"

 

[JesseB]

Hey guys thanks! After a tank or 2 of the gas station I normally stop at, the problem has never came back. The car is running perfect! I also just changed out my autolite iridium plugs and but the Delco 41-108s in it and although it sounds weird, I really think I noticed improvement in some areas. It feels like there is much less hesitation when accelerating (notice it very much in 1st and 2nd gear), which is interesting because I never felt like there was hesitation before, now it just feels better.

A few times I have gotten a code that says car running rich at idle, not sure what to do about this, havnt searched the forums yet, but once I clear it, it wont come back for a long time (a month, 2 months...etc) and I have not noticed what causes it, or what I can do to make it come on quicker or stay off longer...

 

[Bills86e]

May be the injectors pintols occasionly sticking. I send mine to Fuel Injector Service,Outboards,Marine,Motorcycles,ATV,Yamaha. He is real cheap-does great work-gives you a report. Highly recommend, for piece of mind. Fast turn around.

Bills86e

 

[JesseB]

Hey guys, I will be taking the car in to get things figured out since I am contemplating a turbo upgrade. I just started getting the multiple missfires, cyl 1 and cyl 4, as well as P2061 (injector 1 circuit low) just as I have before and it goes away for a couple days, then happens again...etc

I am wanting to go in with a few possible fixes for this, this is what I have compiled:

HPFP

Engine Ground

Check the injector for a short

Dirty MAF (i'll clean it today)

High Pressure Fuel Pump control solenoid intermittent failure (not sure if this is the same as the HPFP, or if the control solenoid is a different part)

A failed/corroded wiring harness at the ECM

I also remember reading somewhere that someone had a group of wires that had kind of rubbed off and was hitting the engine and arcing and causing the problem, which wires would these be?
Also, can you guys think of any other common reasons for this problem?
Thanks guys!

 

[LatinVenom]

The MAF is a good place to start. You could swap injectors and see if the problem code follows the swapped injector.
Check your plugs and see how they look.

 

[JesseB]

Thank You LV! I have not cleaned the MAF once, and Im guessing it probably a little dirty seeing as how I have the K&N Typhoon CAI.

Do I just unplug it, then unbolt it and pull it out and spray this MAF Cleaner ALL over it? Do I spray where the two plugs join together as well, or just the part that is hidden until you pull it out (the metal part)

Also, How do I know when I should clean my actual CAI filter? and I do know not to use oil or use very little

Could a dirty MAF really cause rand mult missfires on cyl 1 and 4 as well as a cyl 1 injector circuit low?

Its just so weird to me because it will come for a couple days in a row, then never do it again for weeks or months, then it will come again (the random misfires and such)...I have a live reading OBD2 tool, so right when it happens and the CEL flashes and the car looses a lot of power, I just clear the codes and it immediately goes back to running perfect.

 

[reedred]

I don't remember what the codes were, but these symptoms sound a lot like when the cat was going on my 07. Good luck!

 

[JesseB]

Ok thank you reedred, is there a certain way to test this? I have Solos High Flow Cat