Diesel Place banner

1 - 13 of 13 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hi!

Have serious problems starting my `94 G20 van! Please help!
When the van has bin sitting for a while ( more than 5 minutes) it get`s
hard to start. It does`t make any different if I have a block heater plugged in or not. Cranking time to start is more then 5 seconds.

1. The lift pump works fine (mechanical)
2. Service engine light comes on intermimittent
3. Engine gode 32 (EGR)
4. Air filter is new
5. Fuelfilter is new
6. Cranking speed is sometimes slow, sometimes fast.
7. No white smoke present upun cold starting.
8. No excessive black smoke during hard acceleration.
9. Sometimes the van "misses" when running.
10. There is a vaccum in the fueltank. I have tried to have the fuel cap
open to prevent vaccum to build up, but it does`t help.
11. The pmd is the "bad" type, mounted on the pump

Could this be a PMD failure?
 

·
Registered
Joined
·
3,964 Posts
:welcome2: to a great place to remedy your diesel problems. I would say check your glow plugs. Good place to start.
 

·
Registered
Joined
·
6,945 Posts
Welcome to the forum, Basune...............

Your lift pump is electrical - go thru the Diagnostic procedure, including lift pump tests.

Your symptoms are fuel supply related, tank to Inj Pump, but you should consider remoting the FSD\PMD
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
As a part of the troubleshooting we installed a one way valve on the incoming fuelline to the injector pump. (did`nt help)Where is the electrical liftpump located?
 

·
Registered
Joined
·
6,945 Posts
Should be mounted to driver's-side frame rail, under the driver's seat - follow the fuel lines from the tank on your G20.

Looks like an in-line fuel filter with a two-wire harness in one end.

Functional lift pump has two one-way valves internally, probably not enough pressure for a third valve.

Perform the Checklist to eliminate all possibilities.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
My pump is located on the lower front right side of the engine, and there is no harness conected to it...
 

·
Registered
Joined
·
6,945 Posts
Hmmmm - could be, sure the Inj Pump is a DS4?

Vans had the DB2 mech inj IP for a while after the trucks went DS4 - you gotta throttle cable?
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
I am shore that I have DS4. Potentiometer driven trottle and the ingektion pump has the FSD mounted on it`s side. I`m also shore the lift pump is working, sinse plenty of fuel comes out of the bleed at idle.

Glow plugs works well. No white smoke (or any smoke) when cranking the engine. It seems like no fuel comes to the injectors.

When the van finnaly starts it runs very well, except for som minor miss every ten minut or so...
 

·
Registered
Joined
·
6,945 Posts
That's an odd duck ya got there, dude - but, the early mechanical 6.2 lift pumps had no drain-back valve and would cause similar symptoms.

The later mech pumps incorporated a drain-back valve to cure that - either yours has failed, or someone installed one of the early pumps.

The one-way valve you used should be between the tank and the lift pump, not between the lp and the Inj Pump.

If you can easily blow thru the 1w valve - you want to make sure the lp can 'draw' thru the valve - move it to the pipe ahead of the lift pump.

Or, try another lift pump - '89 to '93 should do it

What type fuel management filter system does your G20 have - the old 6.2 Stanadyne rectangular style, or the later 6.5 round style?

Also, yes the PMD could be acting up - again, you should consider remoting it.

Check with Beta Maskin - he's in your neck of the woods, and tell 'im I sentcha................
 

·
Registered
Joined
·
5 Posts
Discussion Starter #10 (Edited)
The fuel filter I have is the round type. I removed the inlet hose to the lift pump, and there seems to be a working one-way valve in it. No fuel was leaking out when removing the pipe just after running the engine. But that can also be caused by the one-way valve I fitted upstreams of the fuelfilter,
holding the fuel back. Do you still think there is a point installing a second one-way valve at the inlet side of the lift pump?

I am right now going thru all the earth points from the batterys, and there is a problem with the earth. I will come back when I have replaced all the earth cables...
 

·
Registered
Joined
·
4,805 Posts
bad connections can give any number of weird symptoms. I'm not sure where the grounds (negative cables are called "ground", not earth- similar translation in Icelandic ;) ) are on the vans. On my suburban, there are ground connections at rear-most cylinder head studs on the passenger side. These ground the computer, glow plug relay and lift pump (probably a few other things too). If you don't find any problems at the battery cables, take a close look at these. See if you can cause the motor to stall by wiggling these connections.
 

·
Registered
Joined
·
6,945 Posts
The one-way leak-back valve prevents fuel from flowing back to the tank - it should be between the tank and the lift pump, so there is no possibiility of pumping air to the Inj Pump.

If you're not seeing any leak-back, then that's probably ok.

You must ensure the tank-to-pump lines are sealed and leak-proof for it all to work, but let's look at the electrical system.

As suggested, check the power and ground connections - the cranking speed should not vary, as you indicated.

Start with the battery cables, looking for corrosion, loose connections - check both ends of each cable.

Then go thru the PCM\engine harness grounds, making sure all are clean and tight.

Check the harness connectors, while you're in there.

If you need anything electrical - FSD, etc - Beta Maskin is in Avesta
 

·
Registered
Joined
·
6,945 Posts
Your van has the secondary battery down in the wheel-well under the floor?
 
1 - 13 of 13 Posts
Top