DS4 IP ?s

[gmcheek]

I have the dreaded dieing for no reason problem again. My pump was replaced at the dealer under warranty about 20,000 miles ago. The FSD was the problem then. Now it will die once in a while during warm up only, never when hot. Of course it sets no codes, so the stealership will just keep it a couple of days, charge me check out time and tell me theres nothing wrong with it. I put the tech 2 on it and the only problem I can see is the fuel pulse width time is around 2.00 to 2.04. My buddy says it needs a IP anytime the pulse time is above 2mls and this is probably whats causing the problem.The shop manual says that it should be 1.70-1.90. My question is can I convince the stealership this and what are GM's perimeters on this? Thanks in advance

[jjgmc96]

I'm not sure what there range is but I've observed that when the pulse withe is high or nonexistant it's been the FSD for me. After replacement pulse withe is always steady and not fluctuating.

[lineman]

Hey Gmcheek, I have had the same problem a couple of times.Each time it was the oil pressure switch back by the fuel filter on the back of the motor. It's about a 5 min. job, but it does take a special socket to get it out.My local Auto Zone loaned me a socket the first time I changed it out.I ended up buying my own from my Snap-On man.

[gmcheek]

Thanks for the replys. I don't think its the oil pressure switch because if I remeber correctly it is bybassed at intial startup. Sometimes it won't restart until its sat for a while.
Last night on my way home from fueling it died twice. it died once while sitting at a light and once cruising at about 40 MPH. that is the first time it has died after being fully warmed up.

[gmcheek]

I got back to work this morning where I have the copy of the page out of the sop manual showing the 6.5 data list. It is inj pump closure time that I'm being told is the culprit of my problems.

[ucdavis]

If the pulse width is observably long, you should be getting a DTC 1217. Long pulse would not stall you at 40 mph, but would probably give some smoke (hard to kill the combustion cycle w/engine running by adding extra fuel).
Ask stealership for the IP diagnostic checklist & to go over it w/the tech or service writer to see what they've done. Seems like many stealerships either don't know how to follow these instructions to diagnose stalling, or just don't, & need to be babysat into doing their job right.

[gmcheek]

Thanks for the replys. It doesn't smoke except on takeoff before turbo spools up. My fuel economy is dismal though. I can't seem to get a good answer on this one. I won't take it to the stealership until I have made a diagnosis I can prove to them, and this is the only spec I can see that is out. I called John Kennedy and he said that it was the PMD. Don't know. VERY FRUSTRATING!

[Bill H]

gmcheek,

I'm currently having exactly the same problem. I don't want to go into the dealership either, until I've got it diagnosed myself, for the obvious two reasons, 1) some dealerships will flat out lie and cheat to increase their revenues at your expense, and 2) some dealerships really don't know what they're doing if you don't take them by the hand and lead them down the straight and narrow path. You obviously have some equipment to diagnose that I don't have, and access to some resources I don't have.

DON'T YOU JUST LOVE IT WHEN YOU ASK FOR HELP... AND SOMEBODY STARTS BUGGING ...YOU... FOR HELP? But we have a common goal and maybe we can work together to solve the problem.

Like you I posted here, the popular opinion was PMD failure. Other members said don't expect DTC codes, and some even said unplugging the IP connector, trying to start the motor, and replugging, would give a code that the dealer would interpret as needing a new IP and PMD (covered on 120,000 mile, 11 year warrenty).

I have been following the diagnostic for stalling posted here and have convinced myself that 1) my fuel is OK, full tank, no water, no crud 2) lift pump is OK, 4psi when I turn the key on and when motor's running. 3) fuel filter's OK, changed 1,000 miles ago and inspected yesterday, filter's not dark brown and no crud in bottom of housing. 4) no air in fuel, replaced IP return hose with clear tube and only minor bubble after sitting overnight. 5) batteries and alternator OK, replaced both batteries, cleaned all battery connections, gage in dash always shows at least 14 volts charging when motor's running.

The next steps in the diagnostic are electrical connection checks, including check for ignition voltage on circuit 439 on the FSD. I don't know how to do that. Did you do that yet? Mine is so tight I think I'll have to remove the turbo-to-intake casting to get at the connector.

After seeing your post about only dying before reaching normal temp, I was inspired to hold my foot on the throttle to keep the rpm above 1000 until the temp was up to 185. After that it kept idling for 20 minutes (I shut it off then, thinking it would probably run until the tank was dry). If I hadn't taken the 10 minutes to keep the motor running until it reached normal temp, it would have died in 2 minutes, and might not have started again without waiting up to 30 minutes. When I came back and saw you had later posted that your motor started dying even after reaching normal temp, I was dumbfounded. My new theory of some problem besides the PMD was shaken.

An outfit that sells PMD's and PMD coolers said if the PMD is the culprit, it will occur after the motor is hot, not before it's warmed up, like yours and mine were commonly doing.

I have a complete copy of the Special Policy on IP repair/replace from GM dated 5/13/2003. It includes the step by step diagnostic your dealership needs to do to justify IP repacement (including PMD). thedieselpage.com web site doesn't want to post the Special Policy here because of GM copyrights ??? Is that right ??? Let me know if you want a copy and I'll get it to you. My confidential and untraceable (unless thedieselpage.com gives me up) email is bargain_quest@yahoo.com