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bleucrew6.2
07-17-2007, 08:38
I have a 1989 stock N/A 6.2 that has been getting harder and harder to start. I have a voltage drop when the glow system is activated, and have no visible leaks at the injectors or any of the fuel line connections. New batteries two months ago, and good cranking speed. I've read that the lift pump can contribute to a situation like this, but am not sure how to test it. Anyone have any suggestions? As a side note, I live in the Baltimore MD area, and am vacationing in West Virginnia above the snow line. I'm wondering if the altitude change is agravating the problem....

As always, thanks for any and all help!
Bleu.

Subzilla
07-17-2007, 10:44
Check the glow plugs individually. The quickest is to put a meter on each one and check for resistance - no resistance means bad plug. The other visual test is to pull each one, plug in the connector, ground the base and hit the ignition switch to check for a visible glow. This ensures each wire connection is good. A few bad GP's will create a hard start.

Also, when was the fuel filter last changed? I've solved hard starting with that simple change.

bleucrew6.2
07-17-2007, 14:59
It has been about a year since my last fuel filter change. I do carry one with me at all times, so I could change it out here. When checking the resistance of the glow plugs, am I checking from the glow plug connector to ground- or some other location?

Thanks!

mstockton
07-17-2007, 20:29
Check for continuity between the blad terminal and the glowplug body (threads). I don't know what the resistance spec is, but if its zero, you've got a bad plug.

-Martin

bleucrew6.2
07-18-2007, 04:06
Another note. After initial hard start, the truck will fire immediately even if it has not been run long enough to really warm up. Once its started, it always runs well. I drove it four hours to get here.
Nobody thinks the lift pump may be at all involved with this? I'd still like to know how to confirm that its doing its job.

Thanks!

simon
07-18-2007, 12:23
If you have a testlight with you, pull the wires of the glowplugs, put te alligator clip on the pos batt terminal and hold the tip of the light to the spade on each plug, if test light comes on the plug is prob good, if not plug is bad. .

It could very well be that you have a fuel drain back condition.
Replace the hose on top of the IP to return line with a clear line, after shutdown observe the fuel in the line draining away from the top of the bend to the bleedoff line, but from the bend to the pump should stay full, if it bleeds away then the IP and filter will be empty next morning and it takes longer to get started because the system has to be primed again.
If this is the case, check for leaks , or the liftpump checkvalve is faulty.

bleucrew6.2
07-20-2007, 05:00
Changed the fuel filter. Lift pump worked well enough to purge the air from the filter, but the check valve idea is interesting because the next morning it still took 4 or 5 seconds of cranking for the truck to start. Is the check valve part of the lift pump or is it a separate part?

thanks.

simon
07-21-2007, 16:08
Changed the fuel filter. Lift pump worked well enough to purge the air from the filter, but the check valve idea is interesting because the next morning it still took 4 or 5 seconds of cranking for the truck to start. Is the check valve part of the lift pump or is it a separate part?

thanks.Check valve is part of pump, Do yo have a mechanical or electric lift pump

bleucrew6.2
07-24-2007, 04:57
Truck has a mechanical lift pump. I'm guessing that the check valve is inside the pump, and not a replaceable piece...

Thanks

N9Phil
07-24-2007, 05:38
Check for leaks in your fuel line from the tank to your filter and then to your fuel pump inlet. I experienced the same thing on my 88 just before I sold it. It ended up being a leak by the fuel tank.

N9Phil

bleucrew6.2
07-24-2007, 10:04
Truck is thankfully dry as a bone underneath. I did have some fuel leak issues over the winter, but they were caused by a rusted fuel tank (steel tanks, plastic gravel shield). I have replaced both tanks with poly tanks, and have not experienced any leakage since. Incidentally, the tanks came from MTS, and I was very happy with their customer service and the completed installation (although I can think of better things to do outside in 45 degrees!)

Thanks