Ford 7.3L Diesel Question

[pete.wilson]

Hey all

I have a 95 Ford E350 4x4 minimod ambulance. I took the vehicle in because it was slow to start when cold outside; but the dealer screwed up my motor and bought me a new Ford reman 7.3L turbo diesel. But it still won't start even with temps near 40 with out plugging it in. I also have an intermittent check engine light which causes vehicle to go into "limp" mode with about 40mph top speed, the light usually only comes on for a few seconds/ maybe a mile in distance. The dealer changed the fuel pressure regulator for the check engine light....No fix yet. They changed a check valve for some oil pressure issue supposedly to cure the starting issue....No fix yet. Does anyone have any ideas?

 

[ericvs]

I don't and am not affiliated, but contact Chris at UJoint offroad. He is the mack daddy when dealing with the ford diesels. He is on this site, or you can check his website. Good luck, excited to see this converted to something expo style!

 

[tgreening]

It's been my unfortunate experience to find out that generally the last place on earth you want to take your Ford diesel is to Ford for any serious service. I'm sure they have some good techs, but I don't think there are NEAR enough to staff every Ford garage in business. Chris at Ujoint wouldn't be a bad place to start, and I've had nothing but good service from Powerstrokehelp (search youtube) and a dang sight cheaper than the Ford garage.


Even though they installed a Ford reman, they most likely reused a whole slew of parts from your old engine and probably bolted on whatever was giving you issues in the first place.

 

[pete.wilson]

The reman that I got was the Ford factory reman long block version which included the heads, valve covers, glow plugs, new glow plug relay, etc. I'm sure they swapped some minor parts over. The new motor has a 2year unlimited mile warranty and it now has about 180 miles on it. The total bill was over 10K for the engine, other parts, and labor. I had to call Ford Customer service several times but this whole process has really ticked me off. Especially when my vehicle has only 135200 miles on it. Its at the dealer now; but i have no confidence in the Ford dealer or the vehicle at this point, especially if I go into the mountains here in Montana with it and it gets cold. And I still have the occasional check engine light/np power issue. I drove it to the dealers tonight and it ran fine. I will call Ujoint tomorrow.

 

[Bbasso]

Try your question here. http://www.thedieselstop.com/forums/f14/
I'd offer some assistance but I'm not too sure about the early powerstrokes. If it has a glow plug relay I suggest checking that.

 

[gtbensley]

Any idea what the codes are when the CEL is on?

 

[legendaryandrew]

Replace CPS

 

[snowaddict91]

Being that you are in Billings, I'd imagine there's a few good local, independent shops around. I'd ask the local rednecks where they go and get a second or third opinion to take back to the dealer. Does the truck smoke abnormally when its running good or when its limping along?

 

[pete.wilson]

Hey

It already has a new glow plug relay installed. If it's not plugged in and the glow plugs are cold it will produce white smoke quite heavily and it just won't catch, if I plug it in, it will start easilly, once it's up and running there is very little smoke. There is no smoke when it's in limp mode either, just reduced power and once that check engine light goes out, full power. We do have a pretty good shop here in Billings Heights from what I have heard. The only reason for continuing with this dealer is because it's the warranty factor.

 

[arveetek]

Try your question here. http://www.thedieselstop.com/forums/f14/

Ditto on The Diesel Stop. Excellent Powerstroke resource.

I had a 1995 E350 7.3L diesel that had an intermittent CEL and Limp mode problem. Turned out to be the accelerator pedal. (It's a drive-by-wire model, so it communicates with the PCM). Replaced the pedal assembly, and problem went away.

You'll need to have the codes pulled to really begin troubleshooting the CEL and Limp mode issue. Otherwise it's just a guessing game.

Casey

 

[bajarat]

Replace CPS

^^^^^^^^^^^. What he said !!!!!! Cam Position Sensor

 

[okiebindernut]

Ditto to what other guys have said. Definitely need to know what codes are coming up when the CEL comes on to be able to diagnose that problem. The fact that it produces white smoke when its cranking but not starting points to it still having a glow plug issue. Some people might tell you it needs injectors but the injectors are obviously firing if it is producing smoke. Verify that the glow plug relay is wired properly and functioning properly. You can't go by the wait to start light in the dash, it does not tell you the glow plugs are working. It tells you that the computer wants the glow plugs to work.

 

[Bbasso]

If there is a IDM I would examine it, they are known to get water in them and cause weird problems.

 

[Vandy]

I've got 95 f350. So been there done that. Hopefully this will help


How to check Glow Plug System

To check the Glow Plug Relay (GPR)
· Be sure the engine is cold, so that the PCM will tell the GPR to turn on. If the engine is hot, you won’t have as much time to check.
· Locate the GPR – Its behind the fuel filter on top of the engine, a little bit toward the passenger side of the valley. There may be two relays there. If so, the rear one is the GPR. It will have two fairly large wires (yellow and brown) connected to one of the large posts.
· With your multitmeter set to DC volts, and 15 V range (if not autoranging), clip the positive (red) lead to the output terminal (with yellow and brown wires connected), and the negative (black) lead to a good ground point (like the battery ground terminal or someplace metal directly on the engine block.)
· Turn the key to ON (do not start)
· If your GPR is good, it should click, and you’ll see 11 volts or so on your meter, then, depending on temperature, it will click off up to 2 minutes later. You should do this a couple of times to make sure it consistently makes the connection.
· 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.

If your GPR is bad you can use the factory replacement for around $75, Napa's GP110 is close to this price maybe $10 cheaper. But you can get a GPR 109 from Napa for around $22.00 This is the same exact relay as the GP110 except the mounting holes are rotated 180 degrees, which is no big deal as the wires stretch just fine.
Now if you are tired of replacing your GPR and want a H.D. alternative may I suggest the Stancor 586-902. This is a large relay and it can truly handle the large AMP draw our trucks call for at start up. Gopher Electronics has these for under $40. I know several folks that live way up North (Alaska, Canada) where they know about serious cold starts and they all swear by the Stancor. I am very happy with mine, I believe I have pics of mine installed in my webshots.

To check Glow Plugs.
· Remove the electrical connector on the inboard side of valve cover at the gasket. Press down on the top of the connector latch and pry gently with a screwdriver.
· There will be 9 pins on the valve cover gasket where you removed the connector. The two pins furthest forward and the two pins furthest back are for your glow plugs.
· With your multimeter set to resistance (ohms) and low range (single digits) if not autoranging, clip the negative (black) lead to a good ground point.
· Probe each of the 4 outer pins individually with the positive (red) lead, noting the resistance. Good glow plugs will have a resistance between 0.6 and 2 ohms. If you get infinite resistance on any glow plug, that one is either bad or the connector under the valve cover has come loose.

Also let me add, that if your GPR does test bad you can use a Napa model #109, their book will call for the #110 but the 110 is around $60+ where the 109 is low $20's. They are the same exact sensor spec wise, the only difference is the mounting tabs are rotated 180 degrees, don't worry the wires make it fine. However if you really want a HD relay and one you won't have to change yearly, you should replace it with the HD Stancor unit, the model # is 586-902 and it is made to handle the 200 amp draw, whereas the others are made very cheaply.
Here is a super good resource.
http://www.thedieselstop.com/faq/9497faq/tsb/tsb/sia/siamain.htm

Of you want pm me your email. I should still have the 7.3 "bible". I can email you. It's more than you will ever want to know about these motors. I've got 318 on mine. I converted mine to run on waste veggie oil. She's old but a solid truck.

If all else fails, you can swap your cps (as was mentioned) your IPR can cause starting issues as well as power problems. They are about 80/90 bucks from riffraff-diesel and take a few minutes to swap out.

Good luck

Oh yeah and get OE glow plugs if you need them. The aftermarket ones suck and the tips swell. No fun to get out when they go bad again. Double check your batteries. It may crank and sound fine. But I learned the hard way, it they are both not in great shape, they can be a pain in the butt

 

[Woofwagon]

Sounds to me that the Crankcase Position Sensor is bad. I'll also second that the potentiometer on the throttle pedal might be bad too, this is a drive by wire system as previously mentioned.