Intermittent problem
 

Hey, this is my first time positing on any internet forum. I have a 99 f450 with a 7.3. Here lately it has been "missing" when driving or idling, but only every now and then. When driving down the road it will start bucking and boiling black smoke out then the ses light will come on and like turning a switch everything clears up and it acts and drives normal. Any ideas would be greatly appreciated.

Welcome greencircle. Have you done anything to the truck lately? Any mods? Have you ever changed the CPS. How many miles?


Sounds a little like one of the UNVC harness connectors may be coming loose. Have you ever heard of the 50 cent mod?
https://www.ford-trucks.com/forums/1...-cent-mod.html


Something top look into.

Also see post nbr 20 in the thread below. Shows where a wire commonly rubs causing intermittent running issues
https://www.ford-trucks.com/forums/1...l-issue-2.html

Thanks for the welcome! I recently had the transmission replaced by a local repair shop. I also told the mechanic it was slow to crank In the mornings like the glow plugs weren't heating up. He said the glow plug relay was bad and so was the neutral coming from the pcm....? He placed a push button In the cab and said he bypassed it from original to the push button. Since this mechanic has worked on my truck I have had problem after problem. From the problem I mentioned here to the headlight wires burning up under the dash, it has been problem after problem. I will check that plug under the valve cover and see what I can tell about it. Thank you for your rapid response.

Manual switch for the glow plugs, headlight wiring burning up under the dash? You definitely NEED a new mechanic. It sounds like he just grabbed a battery lead that was "convenient" for the glow plug "switch". I don't recall for sure but I believe that they draw ~100 watts EACH. You could have ha a nice hot dog roast there.

Hopefully he just provided a ground for the negative side of the coil at the small terminal. Does seem suspicious that you had wring problems after a shade tree fix. How cold has it been where you are greencircle?


Edit: I see your in Ga. Where in Ga. Hasn't been cold enough down here to need glow plugs for quite a bit.

Get it home. Tear out everything he did and return it to stock!


Don't turn into that dudes drive again. Your symptoms are easily repaired by this forum until someone (puts in a push button.............are you ****ting me.)

Place everything back to stock. Give us a sign and we'll figure this out very cheap.

Worst thing on this forum is after someone goes in hacking away and you don't know how or what they hacked into.

Look at it like your in a spaceship and running the ****ter and it doesn't work right. So someone splices into the parachute recovery wiring and,,,,,,,,,,,,,it doesn't work.

Hold onto your ankles. Going to be a rough ride.

Denny

I would add this. I ad my trans rebuilt and upon installation, they pinched a wire in the block bellhousing and gave me fits tracking it down.

Inspect the marriage and see if you do indeed have a pinched pos wire. Mine did and I'm thinkin............

Reply
 

I know he did supply a negative not a positive via the push button. I would like it to be stock though for sure! I'm going to get it back to the shop and check for the pinched wire on the bell housing and I'm going to check that under valve cover harness. I'm from Fitzgerald ga, no it hasn't been cold here for a good while but it still takes me a good ten minutes to get the old girl started, I don't have a clue why. Thanks for all the replies!! Also let me add the guy isn't shade tree is an actual shop. Sounds like shade tree work though for sure.

Run
 

Oh lord. And he probably charged you more for the push button install hack than simply replacing the gpr....

First welcome.
Still taking minutes to get it to run? Check/replace the glow plug solenoid.

Even though it was a ground that was supplied it still need a conductor of sufficient size to be able to properly complete the circuit. Just replace the negative/ground cable on your batteries with a 16 GA wire and see what happens. (don't actually do this!)