Hi,

For anyone reading this i started experiencing a slight hesitation and miss under load that gradually kept getting worse over the course of winter 2016 until it wont even pull itself now so it has been parked for 10 months. I ended up replacing distributer (msd) and retimed with spout connector off, new wires 8.5mm ( msd), new plugs (ngk), egr valve, throttle position sensor and calibrated it with volt meter, new air charge sensor, new o2 sensor bosch, new coil (msd), new fuel pressure regulator, check fuel pressure and its at 35 with no hesitations, new pcm in cab.

I pulled the air pump and piping off today as there was a hole in the metal pipe that went to the heads for emissions and deleted it all. It runs slightly better but not driveable in any way. It currently has the overdrive light flashing on the dash and wont stop. ( E4OD) The transmissions seems fine and shifts ok as i replaced that 2 years ago... I had a gnesis scan tool last winter and it came up with the pip sensor which is why i started with the distributer.

I just did the entire steering system and 4x4 the fall of 16. If i didnt i probably would of junked the truck at this point. Any ideas would be appreciated at this point as i am completely blank.

thanks

 

pull codes

 

So i started with the negative ground cable which tested 34 ohms to distributer. I ended up making a custom 2/0 copper cable with soldered copper ends. I checked the ground to the cab and front headlight area that checked out good. I found two broken vacuum lines one was feeding the vacuum canister the other was going to egr. After fixing them i checked voltage to egr solenoid which also was good but did not give vacuum to egr so i replaced the solenoid. After more head banging i pulled codes again ( i did on old computer but they were not the same).

The codes are as Follows:
636 Transmission fluid temp higher or lower than expected
114 Intake air temp sensor out of Range
624 Electronic Pressure Control circuit failure
128 map sensor vacuum hose damaged or broken ( i pulled the hose off
while running which is probably why)
212 ignition module spout Failure spout grounded
327 egr voltage below range
332 egr valve opening not detected

To explain more of the problem in detail, if the throttle pedal is mashed half way or more the truck misfires bad enough it will die in gear, if its in park will continue to barely run until the pedal is backed off about 25% and than it runs fine. It will rev up normally if you dont let pedal down to the idle position again but as soon as you do it will do the same as the previous time.

Of all that stands out to me is the 212 code which seems like its out of time during its hesitation stage under load. I am not too sure where to go from here other than start checking grounds and wiring harnesses?

Any help or input would be greatly appreciated

Thank you

 

Hey Ben,
We had an '87 302 that used to miss under load. Never died, but it pinged and missed a lot when you had it wide open. Turned out, when we timed it, it was missing the SPOUT connector! This caused the timing not to advance when the throttle was open. We got one for a buck at the junkyard, put it in, and it ran great no more missing and got 4 more miles to the gallon! ...till the timing chain busted...
It sounds like you've got a spout connector in there (since you said you took it out to time it), but that trouble code 212 worries me. See if the timing advances when you plug it back in. Don't quote me on this but i seem to remember ours advancing 10-12ish degrees at idle when we plugged it in. Never seen ours die at WOT but it's something to check.
Hope that helps,
Henry

EDIT: As for your overdrive light, trouble code 636 may be the issue with that. You might have a bad Transmission Fluid Temperature Sensor. Not familiar with E4OD trans but the same thing happened to our excursion with 5R110 Transmission. Tow/haul light was going crazy and the trans temp gauge was pegged. Yanked that little dude out and put a new one in and it fixed it. Could be different on yours but its something to think about.

 

Current update on truck problems:

I installed new rear tank and pump and deleted front tank from lines and found rust and debris in return lines to tank while flushing. I pulled injectors which looked oem and hard to come out and replaced with stock new bwd injectors. Truck runs much better than it did but still has a hesitation/misfire while stepping on pedal.

I checked the TPS again, EVP sensor, voltage to oxygen sensor, spout timing continuity to computer, all wires in the distributer harness to computer i ohm tested (all less than 0.2), I also went through the grounding systems again and installed custom 2/0 copper cable with solder ends to block, and 2x 1 gauge copper grounds to body and frame. The distributer to battery negative is about 1.0 ohm now.

Last but not least i was able to borrow the nice scan tool again and did a koer test, fast test, and slow test. Codes are as follows:

koer= 24 Intake air temp out of range ( 150 degrees after warm up)
32 EGR valve not seated closed voltage low
slow=
18 loss of tach signal input to pcm, circuit grounded, spout circuit open
23 Throttle position sensor out of range
56 mass air flow sensor out of range high
66 mass air flow sensor out of range low
No fast codes were found.

Also on the Datastream the o2 sensor is always rich. It seems that every sensor is out of range and they are all new. Something must connect all these togethor to have all these symptoms show up. I am really in need of some good advice as i have read most of the chilton and haynes manuals on the electrical and trouble shooting guides. Any input at this point would be welcomed. Last not the timing chain was checked and it had 4 degrees of slop.

Thank You in advance for your inputs.

Ben Clayton

 

Are you saying you have replaced the computer?
Did you replace it with the same part number unit?
I ask because there was a change of distributor control in the early 90s and its possible that the eecstrategy for the ignition control module is incompatible in your case

 

mudsport 96,

thank you for responding. Yes i did a computer swap based on the vin code of the truck and it did not do anything different but since i couldnt return an installed computer i have left it in there.

Ben

 

Yes thinking back on it i did give them the computer number cause there was alot of options and she wanted to get me the right one the first time. Sorry about that confusion. I have been on and off with this truck for a year so i normally write everything down that i do to work on it so i dont forget. The list is getting quite long .

 

With codes like that I would suspect either a computer or wiring issue.


I see you have swapped the computer already so we can, at least in theory eliminate that. Unlikely (but not impossible) two computers would give the same issue, especially if one is a reman, so we can set that aside for now.


I do a lot of diagnostics on vehicles, but mostly newer stuff these days, so I don't have the specifics of your vehicle in my head currently. However I just bought a 91 f250 with a 5.0 that doesn't run and should have it in a day or two hopefully.


I do have an 88 f250, but it has the 4.9 so not quite the same. (Getting older and the manual is killing my left knee is why I bought the 91 auto.)


In any case the diagnostic procedure is the same regardless of vehicle.


I see you have ohm'd out the wires and cleaned grounds.


Ohming the wires in a practical sense basically just tells us they aren't broken. In theory you could also determine if internal corrosion exists, but I don't ever recall actually finding any that way.


My guess is that you have a spot in the harness were the wires are rubbing against a ground somewhere or are touching each other, engine or body most likely.


On my '88 the relays and computer plug had been pulled out of their holders and had rubbed back and forth on the inner fender over the years and had worn through the insulation.


So what you can do, and may have to, is to unplug the wiring harness from the computer and from the sensors and what not and then check to see if there is continuity on separate wires, if so then they are touching somewhere.


If two ground wires have continuity then its most likely ok, but if a power wire has continuity with any another wire then you probably have an issue (wires rubbing each other). Will also want to check any non ground wire to make sure it doesn't have continuity with ground (wires rubbing against ground).


Another possibility is a poor patch job done by someone in the past. If there are any places where it looks as if work has been done, that's a good place to have a closer look.


Before getting into all that though, I would feel as much of the harness as you can by hand to see if you can find a problem that way - a lot less work if you can.


Also would start the truck and wiggle the harness around a bit in various spots and see if you can make the engine stumble or clean up. Also less work than probing wires.


If feeling or wiggling doesn't work and there are no obvious patch jobs then you will have to continuity check.


EDIT: I have no clue why my reply posted with the crazy spacing. It was actually typed in logical separated paragraphs, but I have to go to work so don't have time to figure that out.

 

I notice you went from having 3-digit codes to having 2-digit codes. 1990 was the last year for 2-digit codes AFAIK. I used to have a 1990 F150 and a 1991 Bronco. The '90 had 2-digit codes, the '91 had 3-digit codes. My current 1991 F150 has 3-digit codes as well.

 

Thank you both for the reply. As far as the 2 code to 3 code is concerned, the first time i pulled codes i used the truck dash and counted the flashes. The last time i was able to use a genisis 5.0 scan tool which all come back as two digit codes. I was curious myself.

I have went further into the computer wiring since last time and did the whole haynes section on grounding checks on the eec harness and computer. Every test came back great. I did not check each sensor which is a great idea and could do that also. At this point if the sensor wires come back ok than im going to scrap the motor and put in a 351w carburated because this truck has had multiple issues for years and most of been made on a friday.

Recently i pulled the front cover off to check the timing chain to maybe hope it was really loose of slipped a tooth but it was 1/2" slack which is time to get changed but shouldnt be causing this much misfiring cause the two dots lined up perfectly when i installed a dial indicator into cylinder number 1.

The truck is torn down pretty good with the cover and oil pan/pump out and im just thinking that it may not be worth my time to fix this at this point and cut my losses short. The problem is above my level and i have spent numerous weeks on this over the last year and im ready for a new motor.

Can you think of any issues that may arise other than the e40d not hitting OD until i get the stand alone controller? I am just mentally done with this motor at this point and need something that is going to give me power and not over heat when under load.

 

That also caught my eye. The other thing is you cannot have codes for the mass air sensor. The truck is speed density and doesn’t have a Mass Air meter.

 

The egr tube ended having a hole in top of upper intake manifold that was wrapped in fiberglass so ether didn't find it . I got a 5.8 Windsor roller cam in now that i switched to carb and deleted all Ford junk. It runs like a million bucks. Just wanted everyone to know if you came across this again

 

You previously stated the truck has an E4OD transmission. How are you running it without the "Ford junk"?