Hey everyone,

Okay, I have a 2006 H3 with 133,000 miles on it. All stock daily driver. I know his issue has been brought up before but while looking it up okne i've yet to see the combination of these two problems and the answers have been so broad that I don't know where to start to troubleshoot the problem anymore.

First, when starting I occasionally get the stall/start. I will turn the key in on position and wait until the dash lights go out to fully turn it over like normal but instead it cranks for a second or two and dies. Lately when it randomly does this I noticed that when I hear it die out and I have already let go of the key it tries to turn over again as if i'm still holding it all the way forward. After waiting my ten minutes (thanks so much gm for your ****ty security system) it normally starts up as usual. I do have one relatively corroded looking coil pack on cylinder 1. I bought a "cheap" replacement on ebay and if I install it I get cylinder misfire and it runs like hell so my bad corroded one is back in. Also after my ten minute wait as of late when I start it up i'm gettin the "fuel cap" light in the dash. This is new and it's always been a good seal the cap looks normal.

Keeping that in mind my second issue is when backing up in reverse very slowly it has literally stalled. Amazingly each time this has happened the security system doesn't interfere (thank god) and I can start it right up and move on.

I don't know if it's an electrical issue somewhere or if the fuel pump is causing it. If it is electrical and if it starts why would it suddenly stop electrically to stall me out? If it's the fuel pump can I DIY that puppy or is my solution just a nightmare of money, time and anger?

 

Update on the situation: I swapped the fuel pump relay fuse #66 with the rear defroster fuse just to see if it helped any.... Nope. Same issue. I tried starting it earlier today with two failed attempts and 20 minute security waiting time later before a successful start.

 

When was the last time you cleaned your Throttle Body?

Wipe off the rubber gas cap washer with a clean cloth.

 

Not recently. I usually just degrease everything and thats it

 

Might want to search out some info on TB cleaning, it is standard maintenance for fuel injected vehicles that you won't see mentioned in your owner's manual.... .

 

Clean the MAF while you have the intake off also!

 

Make sure that you use the correct cleaners on both the Throttle Body & the MAF.

Take the Throttle Body off, it's just 4 screws. The back of it is where the buildup of crap is and you can't get to it from the front while it's still mounted.
DO NOT touch the MAF sensor face. Just spray it with the cleaner and let it air dry.

Examples of the right cleaners:

CRC Throttle Body and Air Intake Cleaner 05078: You

CRC Mass Air Flow Sensor Cleaner 05110: Buy the right Fuel Injection Cleaner at Advance Auto Parts

 

So I plan to clean the throttle body and MAF tomorrow since I plan on being home all day bit I wanted to update you on a little experiment I did. I've taken notice that the "almost start up" happens with my H3 key almost 75% of the time I use it. My husband has a GM labeled key that I believe was a secondary made by a dealership somewhere. When he uses his key it starts most times. In the past week mine has left me waiting on the security system 20+ times and his maybe 2 at most.

Does anyone suggest a key/ignition cleaning as well? How would I do that? Also, I do have multiple keys and stuff on my keyring and my husband only has his key and fob so there's a weight difference. I don't think the Hummer was on that GM ignition recall though...

 

Sounds like its time to replace the key cylinder too. They should be able to tenet it for your current key. I would do that or replace your key with one like your husband's. YES, weight on a key in the cylinder moving back and forth will wear the key AND the cylinder. We have just the key and fob on ours.

 

UPDATE: So we've been using just my husbands key since we narrowed down what's going on. But of course, we get a couple no starts with his key here and there as well. Does anyone have a ballpark idea of how much a new key cylinder is to replace OR is it possible a good cleaning would help the problem? If so, how or who would clean it?