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Discussion Starter #1
First I want to thank the owners of this site, I was a participant back when it was called forddiesel.com and It has been an excellent resource!

I have owned Ford diesels for years, 85 f250, 89 f350, 98 f250, and my current problem truck, a 1999 f250.

I have ignored a problem that has been worsening over the past 6 months, that problem being poor running until up to temperature, and having to crank for and increasing amount of time (over 4 seconds) with the engine hot or cold.

About a month ago, it did something new, it stalled while idling from a cold start, but restarted without problem.

Today it was a no start, turn the key, no GP (WTS) light, cranked fine, and no smoke from the tailpipe. I cranked 3 or 4 times for about 25 seconds each try and then stopped trying before consulting the vast knowledge of this site.

A few hours later I jumpered the big terminals of the GPR and tried again, same thing, good crank, no start, no smoke. I then connected a battery charger and jumper cables to my 85 diesel to get some extra juice and 30 minutes later tried again, still no go. I let it sit for another 30 minutes before I tried again and then I got it started... but it was really not right.

I turned the key, and no WTS light, so I went to jumper the GPR again and when I got to the engine I could hear it cycling but rapidly, a second or two on and a few seconds off so I did not jump the GPR. The dash indicators WTS, check engine, and some other one on the left side were flashing in unison with the clicking sound of the GPS relay and after letting this go on for another 20 seconds I cranked it (about 10 seconds) and it started. Then it did the same problem from a month ago, it stalled 3 times, but this time only for a fraction of a second each time and then contunued running without having to restart.

The truck has about 190,000 miles, and I bought it at 100,000 with the big air filter, 4" exhaust (no muffler), exhaust brake, and I assume (but don't know) chipped, and perhaps larger injectors.

Two years ago I blew an o-ring on the HPOP but I really forget if I replaced the pump too. Kind of sad, I did the work myself.

Batteries, new 3 months ago.
Alternator, new 6 months ago (and also 18 months ago)
Fuel, full topped off with 28 gallons yesterday, I think it holds 38.
Oil last checked, 300 miles ago, changed about 1000 ago, Rotella.

I have never replaced any of the relays, sensors, or computer components in the 4 or 5 years I put 90,000 miles on it.

I have not broken out the multimeter yet, so I have not tested the GPR, but it seemed to work when it was told to. I just did not have the time today to get into this project.

Any advice?

Thanks

Chuck
 

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alot going on hear.
You need 10.5 volts while cranking so keep charger on it.
Sounds like the GPR is shot to me. I would change that first.
Might also want to put new CPS in it.
 

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Discussion Starter #3
Thanks Excavator,

Not being as experienced in this sensor and computer controlled 99 as I am on the older models, is it fairly safe to replace things like the GPR and CPS without risk of damage to them if the problem is farther "upstream" in the computer and electronics? I don't want to buy them twice :)

Chuck
 

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CPS is safe to replace, just be careful when unplugging the connector as not to break the plastic. No need to unhook batteries for CPS.

Now the GPR I would suggest unhooking batts as it is live juice to 1 large oust on GPR all the time even with key in pocket.
 

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The "no WTS light" you reported points to possibly intermittent power to the PCM (engine computer). Do the other instrument panel indicators light up when you first turn the key on? If not, your PCM may not be powering up.

The WTS light and glow plug relay control circuits are independent, BTW.

Try swapping the PCM power relay with one of the others in the under-hood fuse box (such as the heater fan relay). If that fixes it, then replace the relay that was giving trouble relay.

You can replace the GPR or CPS without fear of damaging anything else, but you can test the GPR to be sure it's bad. See the Hard/No Start link in my signature.

On edit: on re-reading your original post, the clicking relays and flashing WTS & check engine lights may just mean low voltage as Excavator suggested. Make sure all your battery connections are good, including the ends of the ground cables on the engine. Battery load tests might be in order as well, as even new batteries can go bad.
 

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Discussion Starter #6 (Edited)
Update:

After a good charging of the batteries, the problem of not starting went away until yesterday. (I drive the truck only once or twice a week).

Yesterday I went to start the truck, waited for the WTS light to go out and cranked for about 25 seconds and it did not start. I turned the key off and then back on and the WTS light did not illuminate this time. I waited a few seconds and cranked again with no luck. Having no time to dive into the problem yesterday I put the slow charger in the batteries so they would be fully charged when I could play with it today. Today I never got a WTS light and cranking did not result in starting the engine (no smoke for all cranking). Following previous advice from klhansen and Excavator I replaced the CPS on general principal. This did not have correct the problem (but I feel better for having replaced it). I then moved on to follow the GPR troubleshooting in klhansen's tag:

· If you don’t get voltage with this test, confirm by retesting as follows.
· Remove the two small wires from the smaller two of the four GPR terminals.
· With jumper wires, apply voltage from the battery across the two small terminals. If your voltmeter now reads voltage on the output terminal, your GPR is OK, and your problem is in the PCM circuit that tells the GPR to activate.

I got no voltage on the output terminal following the directions above and removed my jumpers. THEN with the wires still disconnected from the GPR I decided to again try to start the truck, lo and behold the WTS light illuminated and the damn thing started (60 degrees F here today). From this I deduce that the GPR is bad and will replace that next.

Of interesting note: 4 days ago I drove the truck to work (60 miles) and 3 times it stalled out for a few seconds and restarted itself by not depressing the clutch pedal, this was after the truck was well warmed up.

I really have a feeling that after the GPR, a new computer is going to be next if swapping the PCM controlling relay has no effect.

Chuck
 

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Did you check the PCM power relay in the main fuse box under the hood? If it's intermittent, it could be the cause of your problems. If the PCM doesn't get any power, the GPR, WTS light, etc. won't activate, and the engine has no chance of starting. They're standard relays, and you can swap a non-critical one (like the heater fan relay) into the PCM relay slot for troubleshooting, then if it solves the problem, get a new relay to replace the bad one.

Could also be a loose PCM fuse. The fuse box contacts could be spread too much to make good contact with the prongs on the fuse, especially if someone has used a fuse tap alongside one of the fuses for aux power.
 

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Just because the solenoid is working(clicking) on the gpr does not mean there is voltage going through. My gpr was clicking and was still bad. voltage going in but not coming out
 
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