I have a 1995 6.5 with a cold start smoking & stumbling issue I can't figure out?

[Will L.]

Glad you know what you’re up against- that is often the hardest part.

Imo the best solution is one letter and one number change.
DS4 to be replaced with
DB2

but I get why most don’t, so let us know when she is running happy.

 

[ak diesel driver]

So that's a failure of the fuel selenoid? On mine and Simon's neither of us had any codes. I don't recall you mentioning any codes earlier

 

[Quadstar Tuning LLC]

Glad you know what you’re up against- that is often the hardest part.

Imo the best solution is one letter and one number change.
DS4 to be replaced with
DB2

but I get why most don’t, so let us know when she is running happy.

We discussed that before since it's a manual and wouldn't be too bad to swap. This thing has been plagued for years for Wayne stemming way back to GM putting a reman pump on it for no reason during the recall periods in '95. At the same time, they messed with the fuel supply system and probed a bunch of wires around the PCM. We repaired multiple grounds and Wayne went through every pin to re-tension them where they plug in since someone had screwed with them before.

So that's a failure of the fuel selenoid? On mine and Simon's neither of us had any codes. I don't recall you mentioning any codes earlier

I'd refer to it as "an issue within the fuel solenoid assembly" since there are more things that can go wrong than just a failure of the solenoid. This pump actually had a new solenoid so it's more likely an issue with the head and rotor or unusual poppet wear.

When spec is 0.005" +- 0.0002"...there isn't much room for error.

Will try to update this after it gets torn down.

 

[Will L.]

@quadstar87 we all know you do can carry a tune to good music while rebuilding a ds4,
Do you rebuild db2 and have a test bench also?

 

[MrMarty51]

@quadstar87 we all know you do can carry a tune to good music while rebuilding a ds4,
Do you rebuild db2 and have a test bench also?

Yup, curious minds thinks alike. LOL

 

[WayneB]

Got a Question?

I'm swapping out the IP this weekend. Should I use a lubricant of some kind to try to prime/lube the new pump before cranking it dry for first start?

Thanks in advance!

 

[ak diesel driver]

Should have test fluid in it which IIRC is basically kerosene. You should be good to go

 

[Will L.]

Also, cycling the liftpump before attaching the fuel line to ip (into a container to not spill) ensures fuel is to that point. Then cycle the liftpump a few times to ‘fill’ the ip before cranking doing it with the solenoid powered up is best. Remember you need to bleed the lines so it will start.

 

[WayneB]

John also mentioned putting some Stanadyne fuel additive in the pump wouldn't hurt. That makes good sense too.

Forgot to ask!. I read that you should pop the black plastic diamond shaped covers off the PMD for better heat transfer to the heat sink? Hell I didn't know they had covers? Ya I know. Ain't gotta do with a DB2!

Thanks everyone!

 

[Jaryd]

I would think that if you popped the black plastic covers off the pmd that it would corrode easily and take some life out of it