OK here is the deal. I changed the GPR about a year ago and I just changed the glow plugs. It is better, but like today it was in the mid 40s and I had to crank on it for 10 to 15 seconds maybe longer before it would start. If I only crank on it for just a few seconds then let off and start over it will start right up, I do notice a little white smoke though.

When I changed the glow plugs I checked continuity on all of the glow plug leads they all tested good, but they seemed a little loose where they plug onto the glow plugs, snug but not tight by any means.

Is there something else that I am missing? I do have access to a DC clamp on amp meter, what kind of draw should I see at the GPR?

How about injectors or the pump? Is there something there I should check? It seems as though the truck has lost a little power over the last couple of years, it has 185,000 miles on it.

Thanks Tim

 

Check the fuel pressure at the Shrader valve on the FPR on the drivers side of the fuel bowl.

Low fuel pressure when your cranking could be the issue. There is enough there to make it run, but you have to crank and build up pressure.

The other thing you can check is the HPOP. Is it every time you start it, or just after it has sat over night?
The Hpop could just be draining back down, and you have to crank to fill it up before it starts.


Oh. 55-70 is good Fuel pressure.
Just use an old tire gauge, dont use anything fancy.
they are like 89 cents at the parts store. Just clean it out again and only use it for fuel pressure. I checked a tire with mine to blow it out when i was done. hehe. =)

If you have low pressure, you can shim it up. That should get some of your power back and start ya easier, unless your Hpop is draining back.

 

Thanks for the tips. You ask if it happens all the time? It is much worse after setting overnight but even after it is warmed up I have to crank it just a little maybe 5 or 6 times before it starts.

Thanks again I will check the fuel pressure this weekend.

Tim

 

OK I checked the pressure with a simple tire gauge, a quick on off registered 48 PSI and if I held it for a bit it would climb to 64 PSI.

So now what?

 

How long are you letting the the glow plugs warm up? I've experienced the hard start prior to learning that I should be waiting a good two minutes for the plugs to heat up and shut off. When you turn your ignition to run, watch the voltage gauge drop after about three seconds. That is the GPR feeding voltage to the GPs. The computer will run the plugs for about two minutes (give or take). The voltmeter will increase when the GPR shuts the power off to the plugs. Crank after the voltmeter increases.

It was 22 degrees here last night in eastern NC, and this was the first time that I was able to start the truck without having to plug in the block heater. It's amazing how much having a working GPR and GPs matter.

By the way, thanks to everyone who said to go to napa and ask for the GPR-109. Saved me fifty bucks today. Just enough to pay for a 6637. Sweet.

 

What is a GPR-109 ?

 

glow plug relay - 109

It's a part number, a non-vehicle specific one. Advance auto here could not pull this number up, but napa did.

Advance wanted 70 for the stock gpr, napa wanted 67 for the stock one. I asked for gpr-109, and walked away with a new relay for 29.

 

Well it's nothing I can't deal with, but the truck does not start like it used to. It has only been in the high 30s lately and I have to crank it maybe 10 to 15 seconds in the morning to get it to start. To me that is a long time, I have a 1969 Bronco that starts easier then that. I thought the glow plugs were the problem and when I changed them it did help but still not the way I would like it.

 

Are you cranking the engine immediately after the "Wait to Start" light extinguishes? The Glow Plug Relay has not finished heating the Glow Plugs at that point yet. The Glow Plugs are a large draw of amperage on the system. Our starters need every bit of amperage from the batteries that they can get because of the high compression ratio.

Not only that, but have you had your batteries tested lately? Is the parallel wire in good shape? This kind of sounds like a loss of power.

 

Borderline batteries can cause starting issues. Like Timmy said have them checked out with a load test.

 

Talyn, How do u check the hpop? Im have the same problem!

 

im also having the same problem did you find a solution??

 

Open up the fill plug on top of the HPOP resevoir and make sure that there's oil coming up to within a half inch (maybe 1/4 inch) of the top.