No, I ain't buyin a Ford. I'm trying to help Dad with his recent purchase, a 1993 F250 with a 7.3 IDI engine (non-turbo). Over 120K on it. (I hope he's gonna use this as a learning experience. )
Can anyone point me to a Ford site, or give advice on this engine?
I tried to get on the diesel stop.com, but my login half way works, and I can't get their management to respond to my call for help with it.
The symptoms: stumbling/missing at highway speed. Tach was not working when this happened. Tach and stumbling was fixed by replacing a sensor.
Now, due to the massive smoke at cold starts, I think it has a glow plug problem, but I don't know how to diagnose glow plugs, since my beloved Cummins don't do glow plugs.

I am also looking to find out about any possible tuning of the pump, because of the gray/blue smoke at idle when engine is at operating temp, and maybe some turning up of the pump, if this is possible.

Thanks,
Chris

 

Stamey...to test your glow plugs, remove the leads from the glow plugs, turn the ignition on..and with an ohmmeter check the voltage between each glow plug lead and ground. There should be 11- volts minimum at each plug. If there is no voltage found, check the fusible links or the glow plug harness. ( it may be fried).

To test the glow plug resistance, turn the ignition off....again with your ohmmeter measure the resistance of each plug. Any plug that has a reading of 2-ohms should be replaced. If it has less than 2-ohms the plug is good.

 

there are ford diesel sites much like this one, though i don't recall the exact names.

type "ford diesel" (with the quotes) into google and see what it spits out.

also, aftermarket turbos are readily available for those trucks. if it's only got 120k on the odo then it's probably worth doing, IMO.

good luck (from one dodge owner who can't find too much fault in the old 7.3)


jeremiah

 

dont try to turn the pump down yourself that pump has counterweights inside that if not set right motor will overrev and good by engine

 

Check the glow plug relay. It's fairly common for these relays to crap out.
Check the coolant DCA level. You can buy the test strips at Ford (expensive) or at the local Cummins or Navistar dealer (cheaper).
The Navistar diesel is know to have cavitation problems that will destroy the liners if the DCA level is too low.
My Dad installed a ATS turbo kit on his '93 F350. The turbo really woke the engine up, but without an aftercooler the boost was set to only 8 psi. He wanted it to be reliable. This is the same kit that Ford used in the '94 models.

MikeyB

 

If all else fails, there's always http://www.fordcummins.com

 

Those are good ole trucks and good ole engines. Dont turn your back on it yet!

Glow plugs arent that expensive. Go buy a new set, and change them out(it probly wouldnt hurt at 120k, although i have seen them go allot longer). THEre is a relay at the back of the engine, behind the intake. If the truck ever stops firing, and will only turn over, then replace it. ABout 140 bucks I think.

Trucks that I have been associated with:

89 f-350 250k miles
92 f-350 first engine=500k, 2nd (transplant with 200k) went another 150k.
93 f-350 200k, truck totaled out and engine was transplanted to the 92.

I might add the in the 92 & 93 that 85% of the miles it had a 32' stock trailer loaded with cattle, or horses.


good luck. Depending on what kind of fuel has been run through it, a rebuilt inj pump would wake that truck up.

 

I passed the glow plug diag info on to Dad. Thanks. I'll tell him about that relay also.

Hey Ed, I have been trying to convince him to put a Cummins in his beloved 79 F150, but he thinks it will be too expensive.

Thanks,
Chris

 

If you have a miss at highway speeds it is not a glow plug problem I would say you need a injectiong pump. Check the fitting on the top of the injection pump return line comes out it is like a check valve and when the pump starts going out it will plug and cause symptoms like you stated. It coul also be a bad injector or posibly just slow in time. Look at the injection pump from the top of the engine where it mates to the injection pump cover there should be two scrible lines not where they are in realation to each other then loosen the three nuts around the front of the injection pump and rotate it 1/16 inch toward the passenger side and see if it runs better and cleans up the smoke 1/16= about 2 degree's.

 

Most likely it needs an injection pump. I have replaced them and had the rebuilt do the same thing. Another thing to remember is that the glow plugs do not operate as the heaters in the Dodge do. They only add heat in the pre-combustion chamber to get it started, they don't add any heat after starting.

The easiest way to check the glow plugs is to remove the leads from the plugs, hook the test light wire to the plus side of the battery. It should light strong on each one. If not replace that one.

The glow plug relay system is a problem that goes bad often. They will not stay on long enough when weak, or will cycle too fast. The injector pumps on the IDI is normally only good for 100,000 or so due to a fiber washer in the pump that wears fast. Some rebuilders use a copper washer in place and then the last longer. The pump is the same as the unit on the 6.5 chevy with some thread and linkage differences.

Like was said above, set the timing a hair maybe 1/16 advanced and it will run better. These engines also love to eat head gaskets after a lot of miles. The parts are a lot cheaper than the Cummins though.

 

The sensor that fixed the tach also fixed the missing/stumbling. He is going to check out, and probably replace the glow plugs, as he has received other advice that says he should just replace all of the glow plugs now because they tend to "swell", and if he waits they may swell to a point where they will be difficult to remove.
The fellow who told him about the glow plugs also cared him about the injection pump, saying if he messed with it he could cause serious engine damage.

Thanks for the advice. The Ford site I was unable to log in to STILL has not replied to me email about it. Just turns me off to having a Ford even more.

Chris

 

Yep, they do swell up when they burn out. When I was driving school buses, I did weekend dispatch/yard security, and spent most of my Saturday mornings in the shop bs'ing with the mechanic on duty and generally screwing around and being stupid. We were talking about glow plugs one day, and Bunny (the mechanic) showed me how to make coffee with a glow plug. You just dip it in the cup, hit it with 12 volts for 'bout 15 - 20 seconds, and you have a cup of boiling water. Quicker than a microwave. He left the juice on for a bit too long once, and BANG - it sounded like a firecracker going off, split the side of the glow plug wide open. We must've blown up about a dozen glow plugs that day.

 

Yeah, we were just sitting around the shop, poppin off glow plugs.....



I'll have to try that.

Chris

 

when he replaces the glow plugs tell him to use the motorcraft or AC brand plugs(the 6.5 plugs go right in). They are more expensive than the others but he will have less trouble with them in the future. The pump is easy to add fuel to but it has been so long ago that I messed with one that I dont remember the details. You can`t add that much fuel anyway without a turbo on it to help burn it.
You can add a poor mans turbo(home made propane injection) on it and will see a decent improvement in power and milage. It can be done for under $200 and will add 40 hp or so.
The glow plug relay and wire harness are the weak link on these engines. Most just bypass it and put in a manuel momentary toggle switch and do it manually if they start having trouble .
The pumps are cheep if he needs a rebuilt one somewhere around $350 or so if you shop around.
The cdr valve also give problems. If you remove the aircleaner and there is oil in the intake tract replace it. It will let the engine burn oil from the crankcase if it is bad.
These engines are nown to burn oil anyway a qt. every 800-1k is not unusual. They can run for ever using that much oil. The head gaskets are good for about 150-175k then they will start leaking oil . They can still last quite a while leaking oil if you can stand it.

 

try...........the diesel stop.com