I have a new to me a 5.8 E4OD van with some weird problems.........and it has gotten worse month on end. I have noticed that when I turn the key the rail pump runs on without shutting down after a second....and will not start at that time, on the times it acts right and starts fine, ....at times it will start and while running the engine light comes on and then runs in a limp type mode till I shut it down restart the engine and runs fine again. As I say the pump will or will not act right at any given time and while in the first seconds of key on the pump relay will chatter when the pump should be shutting down. I removed the ECU and found some oxidation on a few pins cleaned them hoping that was the problem........not so ! I also replaced the EEC and Pump relays no help. A few more things the van runs great at times then I get shifting problems along with this newer rail pump problem and a throttle response problem........I think the ECU is the problem any Ideas? Help Me Please. Oh Yeah...I have a OBD 1 tester and now I can't bring up any codes(Will not trigger the ECU to show codes)??? This is a new occurrence also.
Thank You,
vincentdsnt.

 

Hi Vincent,
Weird stuff like this usually turns out to be grounding problems. Many times the chassis is used as the ground circuit and over time, the electrical connections of the body, engine, frame develop resistance which causes uneven or low voltages to the EEC and/or sensors.

The best way I know to find these problems is to run the vehicle with as many things running as possible then connect a DVM to the negative battery post and probe the engine, dash, frame looking for any voltage. Start on the 12volt scale or higher, and switch to lower scales to look for a reading. If you find any voltage greater than a volt, look at the connections/wiring in the ground circuit.

It ain't fun, and it ain't easy but it is the only way to find these problems on older vehicles. My van was an '89 model so I had some of the same problems. The battery ground hadn't been touched in 27 years and was a mess.
jim

 

Hello Jim, and to all the members of this site Hello. Jim as I remember the ground circuit from the ECU proves the rail pump key on ?? So I was working in Dearborn for Ford when this was a new Model year van...........Now I am In Georgia Retired, I found this perfect condition Conversion Van and had to buy it to preserve for the next owner. Perfect except this drivability problem! I will check the engine and chassis ground hoping this will help but this van is so clean I have my fingers crossed as of now. I will also check harness connectors while I do voltage test.......Any Idea why My OBD 1 tester will not communicate with the ECU now? It was working fine earlier this summer?

Thank You,
Vincent.

 

Jim I searched Google for a Ford ECU problem and found this you tube video by Steve Sholtz that is my exact same problem to the tee....I pulled my ECU removed the covers and did find one leg of a blue capacitor rotted off and the board has damage from the leaked electrolyte. I will include his You Tube that helped me and may help others. Thank You for your Help.

 

EXCELLENT, Vincent!
Those value caps are usually power supply filtering, losing those could allow the internal voltages to vary all over the place; any number of erratic symptoms could result. By the way, flat screen TVs suffer from bad caps, the fix is the same one and easy. You should be able to find replacement caps, or a local electronics shop could replace them for you. Probably get all new ones just because.

And Oh My God, is that a mini 7 pin vacuum tube in the video!? Looks like one from the old All American Five radios of decades ago.

 

Jim, I went to Ebay ordered a new Cap in my case it is a 47uf-16 volt 105 degree c value and had to buy a lot of 10 no worries they cost $2.35 delivered to my door.........The old cap is already removed waiting for the mail man. So if anyone is in need of this same cap I will mail them one or two for Free !!! So in my case the erratic symptoms included..
1. Bad gas mileage
2. erratic shifts (E4OD) trans.
3. No communication from my OBD 1
4. Erratic Rail Fuel Pump at key on and while running.
5. Low torque pulling grades while in Overdrive.
6. Bucking while acceleration


I will report if this Cap resolves all six problems .........

And for the record the Bad Capacitor in my ECU was the one below the one replaced in Steve's Video (left Side). ( If your looking down on the board there are two on the left side and One on the right. And as I said my 1990 Caps are of a different Value than his 93 Model but same problem across the board... Read the comments below his You Tube video and you will see this is a common fix.

Thanks Jim !!
Jim My Dyanco Stereo still has Vacuum tubes...Does that make me Old?

 

Old? I have mostly original Fender guitar amps from the 60's along with at least 100 odd vacuum tubes as spares. Also have two Marantz 2270 solid state stereo receivers, back when FM radio was a new thing, ca 1973 or so. Still the best sounding audio equipment out there, guitar and vinyl listening anyway.

 

Old?! Heavens NO (as I think we might be about the same age!)

For all its advantages, NOTHING beats vacuum tubes for raw power especially for audio frequencies. Thankfully we don't have to rely on vacuum tubes for ECU's, however. haha
jim

 

Yes the Rock Stars In the U.K. know them as Valves.............

 

So the Vehicle would then have a a McIntosh under the dash jamming the tunes and Running the ECU duties............Na my guess is tubes for tunes and transistors and chips for controlling vehicles is best. Jim we may be the same age.....Both of us young ! Dang I can't wait to solder in that cap and turn the Key...........

 

Yeah----I'm a Rock Star here in the states----at least in my own mind!

Hope your ECM repair goes perfectly----nothing like a good running truck whichever side of the pond we're on.

 

HA...Being tune deft I am rocking the Dynaco Stereo. But then I save on strings come to think about it.

 

So here is my update on erratic symptoms after the ECU had the new cap soldered in..
1. Bad gas mileage///TBD in a tank or two.
2. erratic shifts (E4OD) trans.///The Trans is shifting spot on.
3. No communication from my OBD 1///Still no communication???
4. Erratic Rail Fuel Pump at key on and while running.///Working Perfect.
5. Low torque pulling grades while in Overdrive.///80% better !!
6. Bucking while acceleration.///80% better

So far after a five mile drive the Van is running 80% better but not to my total liking !! And as you see the OBD1 will not talk to the ECU making me think the ECU has fried from the Capacitor malfunction??? I will try to manually to get codes from the ECU by jumping the test plug to see if my tester is failed then go from there including buying a remanufactured ECU.

To be continued.......

 

Try one of the local auto parts stores to see if they will read codes with their tester. That would point to a tester or ECU problem. It may also be a wiring problem going to the tester.

I was troubleshooting a bad idle problem on my 89 when I found a bad connection going to the AC compressor clutch. The drain on the battery was so high, when the engine dropped back to idle, the voltage sagged enough to cause the ECU to get stupid. I fixed the connection and the idle went back to normal! This was AFTER I had replaced all the 27 year old parts with new so I was really stumped and looking for wiring issues. These old vans will run long enough to drive you to drink. LOL
jim

 

Jim....... As I said this van is new to me, oh I guess I bought it 9 months ago. When I first drove it home I figured it needed plugs and wires at 90,000 miles so I removed the cover and sure enough the van needed some care.......I will list the upgrades .
1.New wires
2.New Plugs.
3.New right side exhaust manifold gasket (leaking).
4.New Cap and Rotor.
5.********New Throttle position sensor.**********
6.Repair of the ECU. (This Week)
61/2.Updating pain to get to parts as you said 25 yrs. of wear updated.

So.....Last night I repaired my OBD 1 Code reader by repairing the ground circuit so I could read the codes without guessing the number of blinking lights. ........(Can't blame the ECU it was the OBD Reader). I have to guess the ECU is 100% and the rest of my repairs are due to bad sensors or wire fails.....and these are my codes.

1.41 HEGO not switching.
2.63 Throttle Position Senor out of ranger....................DANG !!!

I just replaced that TPS with one I ordered online and when I removed the throttle body to swap it out I was thinking this NEW part looks like a piece of China Junk and questioned at that time if I would have a problem with it.
The HEGOS I think I have two are not a problem(but can be!!) the TPS..........Well not a fun job but I guess I need to try to replace a new part with another. I will Win this war !!