Engine Loses Prime

[earniem]

I recieved My Long awaited Duramax/Alison GMC In November 02. 124 miles later I was towed in because it would not start. The people in Yakima Wash. got it started and I drove back home 124 miles and it did it again. The dealer replaced a check valve on the pump and that did it for about 2500 miles then it did it again. this time they replaced the entire fuel tank. That was 200 miles ago and after about a 200 mile trip pulling a 10000 lb 5th wheel I stopped for about a 1/2 hr got in it and it would not start again. The fix is easy with the prime pump on the filter but I dont want to have to do that for the next ten yrs. Does anyone have a solution. My dealer would love to have someone come up with the answer and so would I.

[DMAXTODD]

I don't really have an answer as to what is wrong with your truck,but

[DMAXTODD]

I don't really have an answer as to what is wrong with your truck,but I have the same problem when it drops below about 25 degrees around here. I have to pump the primer 100 times then it starts

would love to find the answer?

[DrL30047]

This happened to me three weeks ago. It was raining, got in '01 D/A and it started as usual -ran 30 seconds then died. Could not restart.

I had it towed in and was told the Fuel Filter had "lost it's prime." My Service Advisor told me they re-primed the filter and replaced a Fuel Sensor. So far - no re-occurrences.

I also noted that after it started and I put it in gear, the transmission stayed in neutral. No answer for this from the dealer.

[Kennedy]

These things can be tough to find. Especially in a non pressurized system. You can check for leaks post filter/primer with talcum powder. Pump up some pressure with the primer and give it a dusting...

[Rick T]

Had the same thing happen to my '01 about 6 months ago. Parked on a slight uphill overnight and could not start the truck. I figured out the loss of prime only after having the truck towed to a dealer who, of course, had no problem starting same. This is absolutely the only problem (and one time, at that) that I have had with the truck in 29,000 miles.

[jbplock]

Just a wild guess but have you checked the quick-disconnect fittings? These seem like they would be prone to leaks, There are two QD’s near the driver’s side firewall at the rear of the engine and one near the tank (I think). They feel loose on my truck but I guess that is normal. I have been thinking of replacing mine with a hose clamp.

[dmaxalliTech]

JK is got the easiest way to tell, its amazing what you can do with $2.00 can of baby butt dust!

As stated above, these problems are a pain to find and pinpoint. GM has a llooonnngg procedure for testing and pinpointing leaks, takes along time and lots of hookups and disconnects and lots of squeezes on the vacuum pump. Have the dealer hook up a vacuum/pressure gauge and pressurize, time the drop in pressure and that will tell them which direction to go in. I am not gonna post the diagnostics 'cause it would take up too much room.

JK, correct me if I am wrong, but woulndt an injector leaking down cause a rough run condition on start up? I would think that unless talc powder turned up something, It is probably in the pressure side of things?. JK, thoughts?