aldav123
3/20/2008 4:51:41 PM
my h1 has been stalling as i'm driving down the road.it will sometimes start if you put it in neutral but lateley i have to come to a complete stop to restart any suggestions?
Injunfarian
3/21/2008 11:29:08 AM
sounds like the beginning to the oh so common PMD overheating issues but not 100% sure. Does it give you problems when trying to start it back up with a hot engine?
hnymlk
3/25/2008 1:27:42 PM
Sounds like the same problem I'm having. What is a PMD? (pardon my ignorance). I've replaced the fuel lift pump and a mechanic says it might? be the injector pump. Was there a silent recall on this problem?
2001 H1 31,000 miles
Injunfarian
3/25/2008 2:16:27 PM
PMD is the pump mounted driver, it basically is the computer for your injection pump. And no worries about not knowing.. I knew nothing about it either when I first bought my hummer.
And yea your mechanic would be right if thats the problem. but instead of replacing the whole injector pump(which cost me over $4500 CDN at the stealership) you can replace just the PMD and even get the relocation kit as well for under $1000 all together.(not sure since i havent priced a PMD by itself yet.) Also save alot of $$$ on labour as well since PMD is a easy item to replace compared to the injector pump.
3hummers
3/25/2008 7:12:27 PM
The PMD runs about $550.00 by itself from the dealer.
hnymlk
3/26/2008 3:28:13 AM
Thanks for all the great info... my hummer will go days without a problem and then it's back again. It used to happen when hot at first but now the trouble is when I first start driving so the engine is cool; perhaps the damage is already done to the PMD?
3hummers
3/26/2008 6:40:51 AM
Odds are it is the PMD. Once they start going bad it is only a matter of time. Have a tech check it to be sure and if that is it make sure the new PMD is mounted remotely so this doesn't occur again.
Injunfarian
3/26/2008 7:51:44 AM
yea PMD acts like that first it starts every now and then and it progressivly gets bad atleast that was my case.
hnymlk
3/26/2008 8:59:09 AM
I'm sold! I'm off to the parts store this afternoon to get everything. They have it all in stock and with any luck we'll be driving it tomorrow and file my test report

Thanks again for all your input...looks like I got a new place on the web to hang out.
3hummers
3/26/2008 2:44:14 PM
Be sure to post the results. Good luck.
hnymlk
3/28/2008 5:28:05 AM
Hi all, Got all the parts but how the **#*# do you get the old connector off the PMD while it's in place. I can get a screwdriver in to pry open the latch but the space is too tight to get a hand in...I already removed the air ducts HELP!!!
Injunfarian
3/28/2008 7:51:46 AM
Wish I can help you hear but I haven't replaced mine myself yet(when it happened to me i took it to the stealership and they charged me almost $5000 for a whole new injector and labour).
hnymlk
3/28/2008 12:41:19 PM
OK I finished the modification. It is running GREAT! I had to heat and custom bend a long flat blade screwdriver to squeeze in between the manifold and the connector to lift the tab. After that it was not bad. Mounted the heat-sink on the front of the relay cover just over the windshield fluid container. Total cost to replace around $650.... Not paying the dealer $5,000...priceless!
Again, thank you all !
fsr7
3/28/2008 4:34:14 PM
ahhh.... stealership prices...
3hummers
3/28/2008 8:12:44 PM
That was a sky high price for both of those repairs.
Injunfarian
3/28/2008 8:48:31 PM
glad i can help a follow hummer owner save money from not doing mistakes I have made :)