Stall While Driving but Idles Perfect

[K5-CJ5]

I have a 96 K2500 6.5 and have recently replaced the PMD, but it was used. It has worked great until today. While driving on the freeway the truck started to die and then came back to life. Then it died but I was able to restart. I got the truck home after having to restart several times. While at home I had the truck running at idle for over 20 minutes with no issues. While the PMD being bad have these same symptoms? Any help would be appreciated.

Thanks

[JohnC]

yea, it could, but check the lift pump and change the fuel filter first...

[K5-CJ5]

Thanks. The Lift pump is functioning as it should and the fuel filter is new. I guess Ill grab another PMD.

[K5-CJ5]

I let the truck run for 45 minutes then took on a 15 minute drive and had no issues. Do PMD's usually given that type of intermittent problem? In the past when they have gone out it would die while idling for less than 15 minutes. I just want to be sure before getting another one.

Thanks

[Lundstedt]

we see a lot of pmds that fail hot and intermitantly, check for good fuel volume from lift pump and then test pmd while acting up

[DmaxMaverick]

we see a lot of pmds that fail hot and intermitantly, check for good fuel volume from lift pump and then test pmd while acting up

PMD test:

1. Remove from vehicle (very important).
2. Drive to a large body of water (preferably in a different vehicle).
3. Throw the PMD as far as you can, into the water.
4. Watch for several minutes. If it floats, it's good.
5. (return home) Install a new (or known good) PMD.
6. Relax. Have a beer (or beverage of your choice). Plan for the next time you need to test your PMD.

[if you have an effective "test" for a PMD, we'd like to hear about it]

[Wing Nut OOA]

lol

sounds like a great test.




howdy all, been a while.

i replaced my PMD months ago, its relocated and on the firewall but its simply on a stamped aluminum bracket. air can get behind it but there are no cooling fins.

http://img259.imageshack.us/img259/4471/pmd.jpg

a couple months ago it seemed like it didnt have much poop while driving it and so i got to a stop sign and floored it (after stopping...) it was really really doggish and as soon as i let off the throttle it would barely go 40 mph. when i got to the next stop sign it died, check engine light came on, i tried re starting a couple times and it finally started, SES went off (bummer), and truck ran fine again.

did almost the same thing yesterday as i was getting on the freeway.

i noticed i ws pulling 10 to 15 inches of vacuum as apposed to 5 lbs of boost.

the more throttle i tried to give it the more it tried to die.

so i feathered it at about 40 mph untill the next exit but at the stop lights i kept my foot on the pedal a little to keep it running.

i got to a burger king and parked it and gave it some gas a couple times, vacuum jumping between 5 and 20, truck sounded like a baby rattle, and blowing tons of black smoke

(my assumption is a major lack of air mixed with the standard amount of fuel? big difference between 5 lbs of boost and 15 inchs of vacuum)

reluctantly i shut off the truck and tried to restart.

fired up instantly, sounded great, ran perfect.

w
t
f
?

[Wing Nut OOA]

http://www.gospelcommunications.org/communique/wp-content/uploads/2006/05/514_Bump.jpg

[JohnC]

1. You need a better heat sink for the PMD.
2. sounds like the intake piping to the turbo collapsed.

[Stratosurfer]

You need the new(er) DTECH PMD. A finned heat sync will work great mounted on a piece of aluminum 1" angle behind your front license plate.