I've pulled engine codes, there was one in there for the air injection system. I tested the tps before replacing. The o2 sensor wires were on the exhaust and melting, so I re-routed those when i replaced it. I'm not big on throwing parts at a problem either. If I had more specs to test against, or wiring diagrams with color codes, I'd start testing the sensors going into the control module.

As for the hall effect sensor in the dizzy and the ignition control module (TFI) I'm not sure of a reliable test, unless the problem is evident during the test.

unfortunately it seems to have two items right now that may or may not be related, I've tried a couple of things when driving.

1. it feels like it has a miss somewhere. I'm guessing it's in the plug wires. so I'm going to ohm them out next. I believe I did this, but didn't write down the findings.

2. when it lost power, with the throttle in the same position, I slipped into into neutral, and instead of revving up, the engine stayed at the same speed for several seconds before finally accelerating. This is the one that is really bothering me. Perhaps a short/open in the TPS wiring?
I think the test for this is to slice open the wiring harness and trace the wires back to the module. Then back probe the module with a voltmeter and drive it till it causes an issue. I suspect the voltage with drop/disappear all of a sudden.

I did drive it with a fuel pressure guage hooked up, but wasn't able to duplicate the issue again while driving. It seems like I have to drive it a good 10-20 minutes before it starts repeating the feeling of losing the TPS signal. Perhaps this weekend I'll get chance to do that, since I may drive it for a good hour. Just dislike driving that long with a fuel pressure gauge sticking out from under the hood.

 

When I worked part time at advance auto parts a few years ago we had a machine for testing the ignition moduals. So that might be an option for you before replacing it

matt

 

If it does it when hot. And gets worse as it gets hot, I'd lean towards the tfi or the pickup in distributor. I forgot all the past history I read here do sorry if you talked about it.
(getting married soon so my memory is dedicated to that stuff)

Other then that, you've put a lot of new parts on it. Keep the new plug wires separated well.

Could be the intake gasket I suppose. I think you said something about that.

 

Not to highjack this thread, I have some what of the same problem.

I have a 95 Ford F-250 xlt. I have the 460 cid (7.5L) (to be politically correct)

When I first start my truck it runs like it's a #apped Ape. I make a couple of stops and it seems to get like it's starving for fuel. I have replaced both front and rear tank fuel pumps. , I have had the computer changed.(Got a new one and now rebuilt twice) Some times when I pull a slight hill it acts like it's not getting fuel. Sop at a stop sign try to take off and it will take off then it acts like it has no power. Push the accelerator to the floor and it seems to get worse. I had the fuel injectors cleaned it ran good for about 250 miles now it's getting worse it's almost not worth trying to fix.
When the outside air temp is low, below 50 it runs great. As the day goes on and the engine gets warm outside gets warm it starts this bovine excrement I took it to Ford and they said there was nothing wrong. Intermittent problem. I take to a mechanic that I trust he can't seem to get it to do any thing I went there last Monday we drove around for about 45mins up hills down hills. Hard stops jack rabbit starts. Nada. I get home let it sit and go to run an errand and it runs like crap.

Could it be the fuel filter or fuel pressure regulator

Any ideas ?

 

What parts have you replaced so far.
I'm going to say maybe you're tfi module is bad or the cat is plugged. Weird how it acts up when hot and not cOld. That's a sign of a bad pickup of module. But also it's in warm run mode. Cat plugged should hold it back all the time but when cold the ecu has the fuel richened.

I'm guessing now. But you may need to throw more parts at it.
Being in ca is the truck mass air. Could be dirty maf sensor or leak in the intake tube maf to tb.

 

Not sure if yours is mass air or not. I don't believe you have OBD 2 either, is that correct? However, with that being said, you've hit the nail on the head with your description on how it runs. You've taken a different approach than I have to trouble shoot diagnose the problem. I've believed mine was electrical, and though things were testing right, i thought it might be intermittently failing. As I stated I think my next step is to verify the wiring harness isn't causing the issue.

UNTAMND

I've replaced the distributor, TFI, Coil, plugs with no significant change. I've gone through a couple of cans of brake clean trying to locate a vacuum leak on the intake to no avail.

This weekend I will start checking the wiring harness, I'm really starting to wonder if dirt and what not from the old tank is built up in the switch over valve which is causing it to starve for fuel, since I assume this is where the reserve fuel would be stored, just a little closer to the main pump.

 

I used my OBD I reader, couldn't find code problems. I have replaced the Dist. TFI, Coil and even plugs and a completes set of wires. I went to the Mechanic today he's going to look at the computer again (this will be #4 if I remember right), he gave me the song and dance this afternoon that it might need a valve job,, and he said that the labor was over 1k. I think he's drawing straws now. I had a car that sucked a valve and another that had 2 burnt valves. If I had a place to take this apart I would work on it myself. Also if I wasn't disabled due to a work injury. If it needed a valve job the transmission would not be shifting as hard as this one is doing now. Like it's searching for gears like a problem with the overdrive. It's a Jasper Trans. He put it in I can't find my paperwork he has done all the work on this truck for the past several years. I know the trans was put in in June of 2010 or 2011.
I think I will look in my bank records for a copy of the check he wanted half of the money up front and I paid him in full. Also I can't find the receipt, but I think my CPA has a copy of the paper work in with our tax records.

I really think it's the fuel pressure regulator. The mechanic says he changed the fuel filter on the truck. I think he did it when he put the new fuel pump in. I need to look at that reciept. (I know my record keeping really sucks)

I will keep you guys advised.

 

Please do! Your right on the transmission shifting like crap! Again. I think you have my truck, probably with less rust and nicer interior though!!! . Someone on here recommended a shop where they have their excursion worked on, so I'm gonna see if I can drop the truck off there this week, maybe even tonight.

 

Just found out that the parts house near by has the Fuel Pressure Regulator in stock for 20 bucks. Figure I'll throw that on! Because I LOVE throwing parts at this truck.. plus if it's right then I'll be happy.. if it's not then I'll still be in the same boat as before.

 

Okay yesterday the Mechanic was supposed to have called me to let me know what he found. So far no phone call, he does open at 0800hrs. (you set your clock by him) No I am not going to call him (seems like you call him and it takes longer ) This shop is a great shop but seems like every time we take the truck in there We Make his Weekly Payroll
Update I did find my cancelled check (actually the duplicate check) for the Transmission work and of course it's out of warranty had the Transmission put in 23Jun09.
Yes I also found a Fuel Pressure Regulator for $60, bucks @Napa as compared to buying at the dealer for $95 bucks.
My luck it really will be something major
Will keep you guys updated.
If this truck wasn't in good condition body wise and interior and the paint, I would really start looking to buy a new one.

 

Talked to the mechanic about 30mins ago. Quote"It ####ing runs like **it!" I think you have an injector problem , Nothing wrong with the computer. It seems to indicate injector problems. . so it's a hurry up and wait again

 

Got the truck back this afternoon. While it was cold it ran great. As the heat of the day got higher, and the humidity went up it ran better but it still was hesitant and shuddering. We went to dinner the outside ambient air temp has dropped from a high of 90deg. to 72deg. the truck wants to run away. I talked to the mechanic he thinks it might be the MAP also. He changed the fuel filter, Also he went thru his records found where we change it 2 years ago. He put a new fuel filter in. I was there when he had it on his bench and cut it open was almost 50 to 60% plugged. I will watch it for a day or so and take it back to him one day next week.

 

I've replaced the fuel filter on my truck 4 times in the last 6 months, thinking that it was crudded up. The first one I didn't even check. The second one, I cleaned it out, and found a very 'mud' like substance in it. The third and fourth seemed clean, however I didn't cut them open. I think I'm going to have the rear tank replaced, the fuel selector valve replaced and the fuel rail removed and cleaned. Or I'll do it my self, not sure where to do it yet though.

 

So I ordered an Equus OBD I Ford tester. Read through the manual and am starting there (again).

Pulled the codes, during the self test I received an 82,85. Per the book,

koeo

82 is air diverter solenoid cicuit fault or supercharger bypass circuit.
or Integrated Relay control module.

85 is Canister Purge Circuit Failure
or shift solenoide 3/4 - 4/3

since this is a c-6 transmission I'll go with the Canister Purge Circuit Failure.

So I dug in that wonderful box of replaced parts and found a little solenoid that was plugged in originally, but not connected to any lines, so I took it out and let it sit in a box.
I re ran the test and found it gave me only the code 82.

So where to the two vacuum ports for the Canister Purge solenoid hook up to? here is a picture of what piece it's talking about though were it sits in the truck OEM I really don't know.



also the canister:




Second question is what is the: "air diverter solenoid?" is this called something else more commonly, like Idle air control valve?

Any help is always appreciated. I'll try to get these two codes fixed and then perform the specialized igntion advance test and KOER test.

 

The top pic is the charcoal canister purge valve. Hooks to vacuum anywhere and then hooks to top of vapor canister. Just set it aside or tie it somewhere. Not really nessisary.

The second one is the smog pump valve. Puts air either into cat or into heads.
It's vacuum operated so the solenoid that controls it (I think by the coil) is unplugged and ecu shows no resistance so throws a code. Check that out and let us know.