95 chevy 6.5 not starting. owner said cloudy fuel

[93chevydiesel]

ok so heres the deal my buddy picked up a 95 6.5 for a good price. the only issue is that it cranks but doesnt start. we dont hear the lift pump run but it sould still start with a bad lift pump. it has a new filter. anything else we should check.

 

[jrsavoie]

Start with the basics. Hot wire the lift pump and let it run. Make sure the filter is bled. These things can be all that much harder to start/diagnose once you suck air into the injector pump.

Run about 1/2 gallon of fuel out the drain T. I use a gallon pickle jar. Watch for crud and look for water balls. Sometimes you have to let it sit for about 20 minutes for the water balls to form.

Check all of the glow plugs.

Check battery cables and grounds.

On a 95 I'd do the double lift pump relay upgrade. There is a schematic here someplace. Just because you have 12 volts or so to the lift pump does not mean the Oil Pressure Switch/OPS is good. Sometimes they show voltage but do not pass enough amps to run the pump. On my 95 the OPS is bad but provides enough juice to trigger the relay.

On a 95 you may well need the lift pump to start. an older IP may not have enough suck to overcome a restricted fuel supply, clogged sock or air leaks.

 

[Burning oil]

x2 when was the filter done? has the truck run since it was installed? That might be the problem. Once air gets in it can be a pain to start back up. You may just need to crank the piss out of it to bleed the air.
Have another PMD to try?

 

[93chevydiesel]

the guy said he did it and cleaned the tank out and then it ran for a day then stopped. now it jus cranks. naw we dont have another pmd. im the only other person that we know that has a 6.5. were gonna start working on it in a half hour

 

[Burning oil]

Truck in gear, turn key to run (do not start engine) and LP should run. Then open the drain valve, fuel should have a good steady flow. If not check OPS & LP.
If he cleaned tank there was a reason. If OPS & LP are OK and no fuel check tank sock and/or blow out the lines.
If still no go get a new PMD (need a spare anyway). Also a fuel psi gauge should be high on the list for a 6.5.
www.pmdcable.com

 

[93chevydiesel]

so heres were we stand so far the lp relay is new and it still doesnt come on. we also went out and picked up a new lp cause the one on there looks rough. tried to bypass but it jus clicks .

 

[Burning oil]

A loud clicking might mean its not primed, while its clicking do you get fuel out the FFM drain? if yes its primed. If no use a rag as a seal and blow through the rag with air to push fuel to LP. As soon as fuel hits it it should get real quite.
Could also be dirty tank sock or pluged line.

 

[ak diesel driver]

I'm betting OPS

 

[93chevydiesel]

wed changed the ops and still nothing. should the lp run when u turn the key

 

[jrsavoie]

A loud clicking might mean its not primed, while its clicking do you get fuel out the FFM drain? if yes its primed. If no use a rag as a seal and blow through the rag with air to push fuel to LP. As soon as fuel hits it it should get real quite.
Could also be dirty tank sock or pluged line.

X2

You will still want to do the dual lift pump relay update. There are links here.

Is the lift pump running when jumpered?

How are you jumping it?

Do you have votage at the lift pump plug? Having voltage at the plug and no running lift pump does not gaurantee the lift pump is bad. The OPS could be to bad to push the amps needed to run the lift pump but still show 11 or so volts.

If this is the case you can probably get by with the dual lift pump relay as the voltage from the OPS will be enough to engage the relay. My Tahoe has been running like that for a long time now.

 

[jrsavoie]

wed changed the ops and still nothing. should the lp run when u turn the key

No. Do more diagnostics before you waste money.

Did you hotwire the lift pump?

On these and most other parts you are best to stick with GM or Ac Delco. The aftermarket parts have been very disappointing for a couple of years.

If you get a GM style lift pump, get one for a 1993. They have slightly higher capacity

Follow the advice in my first post.

Also plug the block heater in for a little assist in the starting efforts

 

[ak diesel driver]

not unless it's in gear, but even then I thought the key had to be in the start position

 

[jrsavoie]

"we changed the ops and still nothing. should the lp run when u turn the key" not unless it's in gear, but even then I thought the key had to be in the start position

ak is correct. In my mind it is just far easier to jumper the lift pump to make it run. It doesn't hurt anything to just let it run even when trying to start.

Do not use a booster charger on this when trying to start. It can do some damage, starting with ruining glow plugs. Thus killing your chances fo getting started.

 

[93chevydiesel]

ok ive got a spare batt ill try it with.

 

[Burning oil]

wed changed the ops and still nothing. should the lp run when u turn the key

Well AK might be right, its either Start or Run. Try it both ways, but I thinks is Run while in drive.

A loud clicking might mean its not primed, while its clicking do you get fuel out the FFM drain? if yes its primed. If no use a rag as a seal and blow through the rag with air to push fuel to LP. As soon as fuel hits it it should get real quite.
Could also be dirty tank sock or pluged line.

To clairify: use a rag as a seal on the filler neck of tank.

 

[93chevydiesel]

ok so we hvae fuel and the lp is running now. there is still no start. on that same note does the PMD run the glow plugs also? the truck will crank over but wont even give a hic-up. any ideas where to start looking and if there is air in the ip is there a way to bleed it or do you crank it. the owner sid he was driving it last weekend and he turned it off and it wouldnt start again. PMD?

 

[ak diesel driver]

time to crack an inj line to see if your getting fuel thru the IP, first I'd loosen the supply to the IP and bleed it at the IP

 

[WarWagon]

First off the lift pump is critical. You replaced that and now have a rattle. You need to make sure it is primed and has flow.

What did the fuel filter look like? What did the bottom of the Fuel filter manager look like when the filter was out? How about the last ditch screen on the center post of the fuel filter manager? Do you have fuel pouring out the bleed valve on the filter and the water drain? Jump the relay contacts under the hood for the lift pump is what I do.

Cloudy fuel may have water in it, bugs and what a mess that is looking at my recent posts, or gelling up from cold. It may be normal - use the settling out advice above to check for water.

As the lift pump wasn't working - well my 1995 stalled and would not restart because of that combined with a plugged tank sock. Never replace the tank sock - leave it off and use an external spin on filter before the lift pump - that is unless you like dropping the tank to change socks. A plugged sock will prevent a lift pump from priming and cause it to loose prime and just rattle.

Also the bad lift pump could have overheated the PMD.
Check here to troubleshoot the PMD and pump in a PDF doc as it has a no fuel output section.
http://www.thetruckstop.us/forum/sh...ge-DS-6-5-DB2-5-7L-info-online-from-Stanadyne!

 

[Burning oil]

GPs are not controlled by PCM, but by the relay. What shape are GPs in? GPs are pretty cheap so you may want to start out with a fresh set. How long have you been cranking it? To confirm: you are now getting a good steady volume from the drain/air bleed on FFM?

 

[93chevydiesel]

ok so heres the progress. it runs finally. the lift pump/ lp relay/ it has a fuel leak on the back of the motor. we also had a buddy with a 96 6.5 come over and he let us unhook his pmd and then it finally fired off. the motor is very noisy when started. its kind of like a draging flywheel but it mite be from injectors.