So I have a 1995 F-150 4.9 with a manual transmission, a few days ago I noticed it started sputtering and hesitating ​while accelerating. It started getting worse and began doing it while It was just idling, now upon cranking it, it fluctuates idle rpm pretty erratically.

I decided to run the codes and it threw up a 211, indicating a PIP signal, we looked at my distributor and it looked awful, we were surprised it was running at all, so we replaced it, ensured it was placed in exactly where the old one was to make sure not to throw off the timing. After disconnecting the battery to reset the computer, it still threw the pip code. I cranked it up and ran the code engine on, it was now showing a 173 (Lambda sensor (right) too rich), a 213 (Tach, circuit, SPOUT grounded. SPOUT circuit, open circuit), a 126 (MAP voltage above spec).

What we've done so far•new distributor
•changed MAP sensor (off a parts truck we have)
•checked fuel pressure (it was around 60 engine off, 55 engine on, within what the haynes manual said)
•put new fuel filter and spark plugs a couple years back
•tried using the PCM from the parts truck, was still having the same issue
•checked voltage and resistance on PIP, MAP, TPS
•used injector cleaner
•rubbed the dash and said a prayer
I've read several forums of people having similar issues to mine, and I've tried pretty well everything others have suggested, I'm at a stand still and have no idea what's going on with it, anyone have a suggestion of something I may have missed? Or what I should try next?

 

Check the timing with a light to verify that it is set properly, and retest the new PIP sensor. Aftermarket distributors for these trucks are notoriously garbage. If it seems like an ignition issue, check the TFI module on the fender as well, and does it run any better with the SPOUT connector unplugged? And it can't hurt to pull the plugs just to inspect and recheck the gap.

 

Maybe double check the work you've done to make sure everything is tight before you move on. I changed my distributor when I had a PIP issue and worked fine for a short time. Then it started running rough and progressively got worse. Ended up that I forgot to tighten the distributor bolt after I adjusted the timing and the distributor moved.

 

First: never change any part unless it's due on the maintenance schedule, or it fails a published test. Being dirty is not a fail for the visual inspection (which IS a published test) - it just means you need to clean it.

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And when you replace a part, make sure the replacement passes the same test that the previous one failed, BEFORE letting go of the previous part.

Second: generic code definitions are far worse for EEC-IVs than for OBD2s, so only use the definitions on this page, and never use a scantool to get the codes. Use only the jumper wire:

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Third: you cannot eyeball the distributor position, even if you had marked it beforehand. It MUST be timed with a light according to the instructions on the VECI label (or service manual).

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Fourth: testing the ignition system is far more complex than simply volts & ohms. Read this page carefully a few times before beginning the procedure:

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Do not waste your time reading what other people did to other trucks with other problems, no matter how superficially-similar they may appear to yours - focus ONLY on your truck, and the logical diagnostic processes in those links & Haynes.

You should put ALL the truck's details & history (as much as you know) into your signature so it shows with each post, as this page explains:

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Phone apps don't always show signatures, so you may need to switch to a real browser in desktop mode on your phone, or just use a desktop/laptop computer. Put your location (nearest city) in your profile & upload an avatar of the truck. The more pics you post of the truck, engine, wiring, labels, & undercarriage, the more likely we can help you. Not all its details are relevant to these issues, but you don't necessarily know which ones are relevant, so just put everything in now.

 

This past week one of my friends brothers bought the same truck with the same issues.....The fix was quite simple and elementary....Heres what I did to make his truck purr like a kitten and it took a full day to do too.....

The issue was power and grounds coupled with age and lack of maintenance.......

The EEC-IV is a very finicky system and age takes its toll on the whole system but all is not lost.....Alls needed is a lil understanding to how the EEC-IV system operates..

Its a computer and it hates electrical interference so to cut down on it Ford ran the grounding wires to the place with the least noise interference....The core support.. The core support is grounded to the frame,fenders and the battery aux wire.Over time the grounds become weak and people chop into them or stack other grounding wires on top of them thinking theyre just ordinary run of the mill grounding wires but theyre wrong and if they did add anything to the ground wires they just messed with the ECU and how it senses power to ground using two separate grounding wires coming from the EEC on pins #40 and Pins #60.....

On my truck and most trucks Ford put the grounding wires for #40 and #60 here on top secured by a 10mm fine thread metric screw....As you can see the screw snapped but the hole next to it was still available...



Another thing to touch upon is the EEC and the FuelPump relays and the relay ground on the EEC side...Its hooked to the same spot as Ground wires #40 and #60..Mine was put on the header panel ground screw for the headlights....Look at this diagram ..Its not mine nor is it for the F150 but all EEC-IV ECU's are powered and grounded in the same or similar ways..When the ECU senses a huge differential in resistance between the two wires it will throw a code....If you notice pin #60 is a clear unobstructed ground path and pin #40 has the MAF circuit and the ECU internals...Too much differential in the two pins and the CEL illuminates..


Now look at how the battery power comes in from the battery to the relay then out of the relay to trigger the fuelpump relay aswell as power 16 12v items plus the ECU on pins #37 and #57..Some computers have only 1 wire on #57 but the principal is the same...If the ECU doesnt get the right power the ECU throws codes..

Relays that arent protected by relays have a 10year service limit..After 10years no matter if its still operating they must be retired and replaced..The contact inside that transfers the power gets oxidized and gets weak..

If you look at how the relays work the EEC relay powers the fuelpump relay so if the fuelpump has to work harder due to poor grounding of the alternator and the battery or just plain old age making it spin slower it will put resistance on the EEC relay causing voltage issues on the MAF circuit..Even poor and sticky fuel injectors will cause issues too...One of my modifications to stop the EEC from being taxed by the fuelpump relay is to tap into the trigger wire for the EEC relay and use it to power up the fuelpump relay too and eliminate wire for circuits #37/57..

Some will say theres a reason for having the Fuelpump relay coming on as a slave to the EEC relay and Ill say yeah I agree but it is actually overkill and a bit of overthinking as the circuit on #22 controls the ground on the fuelpump relay that cuts the fuelpump after 1-2 seconds after the fuel pump relay is energized...If the EEC relay doesnt trigger the the ECU then the ECU doesnt complete the ground circuit for the relay...

If you get an authorized genuine Ford glove box manual for your truck in the manual is a maintenance schedule on what needs to be checked and replaced at the intervals recommended..

One thing Ill say is and thats 100% for sure is the 80,000 mile recommended Timing Chain with thrust plate plus waterpump and thermostat replacement should be done religiously....Before the major overhaul my F250 made it to 565,000 miles and if not for the major blowby it developed it was still running quite strong but the blow-by stench was stronger so instead of buying a new POS that wont last the 31 years it lasted I put the $23k the truck costed back in 1991 back into it and glad I did as I also did alot of major improvements to the frontend suspension Ford should of done too............Like these beauties I installed in the frontend 16years ago to get rid of the rubber bushings and give the frontend a more positive feel.....Makes my worktruck handle like a NasTruck and I also got rid of the gas pressurized shocks for non-pressurized ones and the ride n handling is insane....LOL







What we ended up doing was taking out the starter and cleaning up where it mates to the transmission and the transmission mounting spot, we removed and replaced the starter solenoid with one thats diode suppressed, removed the 4 gauge starter power wire and replaced that then we removed and replaced the battery ground wires with cleaned up grounding points, removed the alternator and the alternator bracket then cleaned up the spots where they ground to the alternator body and the engine block plus cleaned up the spots for #40/#60 and the EEC relay ground wires......

Then we created an Octopus style grounding point using the engine block as the center of the star........Same as this one...The engine is grounded to the frame and the cab also the negative post on the battery,


Then we cleaned up the ground wire on the top of the inner fender near the ECU aswell as the HEGO ground wire and when we did a continuity test we found out that the 02 sensors wasnt grounding to the exhaust pipe so we removed the 02 sensor and cleaned the 02 sensor tip in a shotglass half full of lemon juice and used an orange medium abrasive wire type wheel for the drill chuck to clean the o2 sensor threads and retapped the thread hole in the exhaust pipe with an 18mm tap...I rinsed the sticky lemon juice off the 02 sensor with non-chlorinated brake parts cleaner and then hit it with a plumbers torch to defume it...Then I replaced it

Next thing we did was replace the fuel pumps in both tanks and the fuel regulator aswell as the fuel filter and the fuel injectors and the fuel pump relay with a relay with a protective diode..We put a relay with the protective diode in the EEC relay too and rewired them with new relay sockets...

Next thing I did was check for atleast 22kohms of resistance on the IDM circuit wire coming off the TFI module and there was no resistance to my surprise...The old owner installed an ACCEL TFI performance module #35369 which is a push start TFI module on a truck with an automatic transmission and didnt add the 22kohm resistor or didnt simply buy the black TFI module #35368.Luckily for me I had an ACCEL module #35368 so we swapped them...

We pulled the sparkplugs and saw the old owner put double platinum non copper resistor sparkplugs and even had them gapped wrong to .035".....We put Autolite #24's gapped to .045"

After we got it initially started we pulled the spout and the IAC wire and set the base timing to 10*btdc and set base idle and checked fuel pressure also put a vacuum gauge on it to see how many inches of mercury it was pulling.

I shut it down, reinstalled spout and IAC plug pulled battery positive and grounded it against the battery negative wire to completely and quickly drain the battery...

Upon restart the thing ran better than ever before until it started running hot so this weekend we are gonna replace the T-chain,waterpump ,thermostat hoses and radiator plus flush out the heater core and do an oil/oilfilter change.....

Heres what it looks like inside a radiator flow tank when you assume the radiator flush did its job.........LOL


Basically in a nutshell if you take the time to disassemble key components and clean them up and replace the items that should of been replaced ages ago you can get your oldie running really goodie...LOL

Good Luck

 

I apologize for not responding to any of the replies, honestly this thing was frustrating me so much I completely forgot I posted anything. So test after test after test and many hours hunkered over the engine bay, I found the issue. I started getting inconsistent codes come up. Spout, pip, map, 02, EGR, all at random times, I tested everything. I checked my spark plugs and almost everyone of them were worn inconsistently and several had cracked ceramic, so I replaced them and a few of the wires were pretty nasty so replaced those too. Nothing, still the same issue. I checked the O2 sensor, it was nasty as well, it was the stock one from the factory, so I went ahead and replaced it, nope, not that. Tested map sensor, it was shot, so I replaced it, it ran like a dream! Test drove it twice at my brother's shop, was perfect, got half way home after the two test drives, right back to where we were, running like garbage again. We tested the EGR and it was fine, I was starting to get concerned that it was the injectors or something, but thought why would it run fine one minute then run like garbage the next. We were stumped, we've worked on allot of older Ford's, we have 2 89s, 3 95s, and a 97 all on our family farm, we've gotta figure it out. My grandfather talked to a friend of his that was a mechanic at a Ford dealership for 40 years, told him the details, he mentioned that a failing computer could cause sensors to not read properly (or something like that, I'm not very familiar with it all) and cause the engine to run horribly, causing unnecessary wear on the components that I had to replace. So I gave his advise a shot, replaced the computer. She's back to her old self again, not a single sputter to be heard! The only issue I have now is I'm still getting an EGR code, the guy said it's possible that it has allot of carbon built up, haven't had time to look at it but will probably get to it this weekend