I have a 1988 F250 diesel that is very difficult to start at any air temperature. It starts within 3 to 6 turnovers when I have the heating unit plugged in for long enough. I had one mechanic
extensively work on it, and now another shop. No one can find out what is wrong. With heat it starts easy. Have had the following done:

- New starter installed Jan. 2000 ($500+)
- new glow plugs (AC Delco) Jan. 2000
- 3 leaking fuel tubes replaced Jan. 2000
- Air leak fixed by having a rubber hose replaced Jan. 2000
- New fuel filter

- New glow plug relay control unit Sept. 2000 - (1st unit
ordered was defective and exchanged for another which the
mechanic checked out as working)

Following in Sept. 2000:
- New glow plug wiring harness
- Used but in immaculate shape main wiring harness (Ford
no longer manufactures this) from an '88 F250 diesel.
- Clamps for fuel tubes as another leaked and was replaced.
- Re-built injector pump. Mechanic pressure checked lines
including the line to the fuel tank and also dropped the
idea of adding a check valve to this line as he concluded
no fuel was being lost (Subsequently the 2nd shop I had work
on the truck concluded there was fuel being lost but after
examination decided none was).
- New injector tips (spray nozzles inside injector).
- New fuel filter.
Truck subsequently had the same problem. First mechanic finally insisted the truck needed a valve job and after rings were checked, maybe a ring job. I took the truck to Winner Ford
of Dover, De. and told them I wanted a valve job and no diagnosis. They checked the compression and found 370 the lowest, 375 the second highest, and 400 the highest. They claimed they cranked each cylinder only 4 times. First mechanic claimed they should have disconnected the main fuel tube because fuel might seal the rings and cause a higher pressure reading than normal. I and my father thought that did not make sense because in a normal start, would not the fuel be there anyway? Winner Ford said they disconnect nothing. Winner Ford said the relay control unit for the plugs was bad. I just had a new one put on in Sept. 2000. We are now into early Nov. 2000. I was desperate to solve this problem, at their mercy, so gave the o.k. They also charged me for the diagnosis which totaled $429 for the relay control unit and a new replacement plug as one had burned. I took it back to them and complained later as the problem was still unsolved. They kept the truck two days, and the mechanic angrily insisted that the only thing wrong with the truck was that the batteries were too weak. He said they only put out 650 cranking amp. That was funny, I had bought 2 850 cold cranking amp batteries less than a year ago from PEP Boys. I then bought 2 900 cold cranking amp batteries. No effect on problem. Winner Ford insisted it did not need a valve job. My first mechanic continued to insist it does. The truck starts easily with heat, but often takes 5 or 6 turnovers of the engine. It often, but not always, tries to fire after about 2 or 3 turnovers but cannot. The first mechanic says it is trying to fire on the one 400 cylinder but cannot on just one cylinder. I say maybe so, but why doesn't the remaining cylinders pick it up? They don't, only when the engine is warm. Winner Ford said they wanted to install all new glow plugs of the same brand. It was they who put in a different Motorcraft brand to replace the bad AC Delco. They said they would pay for it if it did not solve the problem, and if it did solve the problem, I would pay for the plugs and not the labor. I agreed. They put in the new set and I tried to cold start the truck in 30 degree temperature. It turned over 9 or 10 times and I turned the switch off. That's another subject. The first mechanic claims that the more turnovers, the more heat to the plugs, and the mechanic at Winner Ford claims the opposite. That is why any time the truck turns over more the 7 or 8 times I quickly kill the switch so I don't take a chance on burning any plugs. Anyhow, I tried again a minute later and after about 8 or 10 turnovers I turned off the switch. I waited 2 minutes by my watch, and tried again. I made the decision to kill the switch at the 9th or 10th turnover and the truck began to fire. Because of my turning my wrist it killed that. I tried again, and the truck started within 2 or 3 turnovers. I will wait for 50 or 60 degree temperatures in the mean time and simply use the heating cord for colder than 45 degree starts.
My first mechanic says that there is no different type of plugs just different brands. So does the mechanic at Winner Ford. Incidently, the new set of plugs have the light stay on for 20 seconds or more. My old set only stayed on for 7 to 9 seconds and my first mechanic says that's all they should stay on is around 7 or 8 seconds. I have recently read an e-mail from a man who had trouble cold starting a 93 GMC diesel truck. Somehow he was talking about ohm heat resistance. That the standard plug has a 2 ohm and that he had a friend who had a .7 ohm rated plug at 15 amps. He said he got a set of plugs rated between .5 and .8 ohms and would take up to 18 amps. He said the problem was immediately solved and furthermore, he could cold start without the heating unit at 19 degrees. There's got to be something to that. Can anyone tell me what's wrong with my truck? The seven plugs taken out of it were said by the mechanic to have 3 that were questionable as far as being in good condition and one was bad. I am wondering if higher resistance plugs are not recieving too much heat even with a 3 to 5 turnover start? Then maybe being super-heated at the few occassions when I turn the engine over more? In the past 2 months with the old set of AC Delco plugs I've started the truck about 35 or 40 times with the heating cord. And up until recently, about 30 or 35 times at the farm where I hunt
with the residual heat from the engine in about 3 to 6 turnovers.
Once in 35 degree temps. we were longer getting back to the truck from being on deer stands (3 and 1/2 hrs. instead of the usual 2 and 1/2 to 3) The truck turned over 8 or 10 times and I killed the switch. I tried again a minute later and it turned over about 7 or 8 times and started. Then, on a 25 degree morning duck hunting, I tried the truck after it set for 2 and 1/2 hours. I turned over more than 10 times and I killed the switch. A minute later it turned over 9 or 10 times and started.
I ran it for 25 minutes to warm the engine. An hour and a half later, leaving for lunch, I tried and it turned over 8 or 9 times and I killed the switch. Then I tried and it started within 5 turnovers. The next Sunday, in 50 degree temps. I tried
blowing a hair drier on hot into the air filter while I turned
it over. My father suggested it, thinking the hot air would help
start it. I doubted it. Anyhow, it turned over about 13 times and did not start. I tried once more with as many turnovers and had no luck. Those 5 times are all that I turned the engine over more than 6 times. Out of 70 or 80 starts. So why would that few times ruin or start to ruin the plugs? I think it might have something to do with heat resistance. At the pressures I mentioned, it should not need I valve job, but I don't know that either. I desperately need someone to tell me what's wrong. I paid $5900 for this truck in March 1999. It has 128,000 + miles on it and seems to run good. I've spent over $3500 on this problem alone. The previous owner had it 6 years and the owner before him had it since 1988. I think I've got an otherwise good truck here and I just need to find out how to solve this problem. Sorry to be so long but I've e-mailed in other forums, and what little replies I get ask me questions that I've already had the subject accounted for. Hence, I simply try to tell all I've had done to the truck here, what the mechanics have said, and how the truck is acting under what circumstances. I would appreicate any help I could get.