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Cant get to the bottom of it!

T

Thor001

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Hi folks, I am having a problem, nearly 1000 miles and 3 countries from home, cant find a mechanic with OBD1 reader. Brit over on the European continent, been struggling with it for a few weeks I have limited mechanical knowledge, not nill but limited. Had some advice from here which took me down this path.
Service Engine Soon light comes on anywhere from 1-25 miles into a journey, obviously limp mode kicks in and as it says on the tin, were limping from there on. It seems to need a couple of hours before it will start up without the light on but it then comes on again soon enough. I discovered the lift pump was not working so I ordered one. When the LP arrived I fitted it and it was working fine, went for a drive and low and behold, the light/limp mode back on. Checked the LP and it was not working. Tested the circuit and found there was not consistent power and sometimes non. Tried putting power down the secondary wire coming from the relays in the engine bay on advice of the guy I bought it from, seemed ok, went for a drive and same thing. Cutting it a bit shorter I decided to run a new wire from the fuse box off a switch, turn it on and off at start up, must be fixed right? Just been for a test drive, the engine seemed to purr and drove smoother than ever, fantastic, then, light on and limp mode back, LP working fine. I have put a wire between pin A and B on the OBD terminal and counted the flashes, the code is 13 which I believe is the fuel shut off system, that is beyond me but maybe it would switch a light on in your thoughts! Any of you guys have any ideas because if I bang my head against the wall any more I am either going to put a dent in it or me. I have spoke to a couple of local mechanics but cannot get any of them to look at it without taking it in but we have our dog with us so cannot just book into a hotel. Would really appreciate any help you could give.
1995 Safari Trek motorhome
GM 6.5TD
 
Find the fuse to the Fuel Shut Off Sol. Shine the fuse spade up with Emory/Crocus cloth or fine sandpaper.
No other codes? Code 13 generally doesn't give a check engine light, just a stall situation from fuel being shut off in my experience.
 
Hi Thor. I remember you had a couple other threads about your rv, so I looked them up for referance trying to help me with info about your rv. To save time for the others: A steaming & no temp gauge problem http://www.thetruckstop.us/forum/threads/any-help-would-be-apreciated.44765/#post-510298

And a misfire problem http://www.thetruckstop.us/forum/threads/missfire.45005/

You never posted final outcomes on them, so I'm not sure if we're dealing with continued problems from there. Have you had the limp mode back in those issues?

I'm suspecting some electrical gremlins. I'm guessing we are dealing with obd1 and a db2 pump, but it would really help to know. Take a picture of the obd connector, and the injection pump, please.

We need to determine if your transmission is defaulting from itself or signal from the engine.

Did you fix you temp gauge issue? Bad sensor or connection issue can feed information and cause chaos.
You have 2 temperature sensors on the engine. Could be left front head, right rear head, coolant crossover pipe, or inline of hose. Rv build can put them just about anywhere. 1 sensor is for your gauge, the other feeds information to the power train.

You can have corrosion/ connection issues feeding to the pmd if ds4 pump, or to the TCM if db2 pump.

If you get where your waiting around for information back and nothing else to do on it: start pulling grounding connections off the engine, clean them and reinstall.
 
Hi Will, sorry I didn't round the other posts up, I had a new temp gauge fitted. The misfire turned out to be my ignorance of the limp mode, this seems to be that original problem confused for misfiring, obviously progressing and getting worse. The bus is definitely OBD1 connector but to be honest once you started talking about pdm tcm you lost me, I will try to get a photo of the injection pump, (when I find it)! Thanks for the response.
 
Hi NVW, I could not find a fuse for the fuel shut off but checked and cleaned up all the fuses a couple of weeks back as I remember you advised it back then. thanks for advice
 
Just as a thought, as I do not have a OBD1 reader I have not cleared the code after replacing the lift pump, as it does not come straight on could it be coming back to bite me in the arse or would it come on as start up if it was not clearing?
 
Disconnect the batts for awhile to clear the codes. On the trucks you can leave the trans. in drive with your foot on the brakes and accelerator for 30 seconds IIRC. Ign. on, eng off of course.
 
Hi NVW, I have done as you said and have cleared the codes, now showing nothing. Only problem is the bloody snow is still falling and cant take her for a test drive to see if it kicks back in.
Will, thanks also for your help, I am learning from lots of research over the last few weeks but I am still 20 years since tinkering on engines, on the bright side it is from that era so that helps but still only very limited knowledge, on that note, I have took a photo and hopefully it will give you an idea as to what components were talking about.DSC00202.JPG
 
Good pic. You have a ds4 injection pump. The pmd is a Pump Mounted Driver (aka FSD Fuel Solenoid Driver). It is mounted on the side of the injection pump that has the multi wire connector going into it.

You're looks like it's been there for years. In the pickups, the under hood heat swing kills them, so there is a heat sink and wiring extension harness that relocates the to the back of the front bumper. When it's time to do yours I would relocate it for the labor saving time.
http://leroydiesel.com/products/leroys-stanadyne-pmd-relocation-kit/

There is no diagnostic procedure for a faulty pmd, only replace with known good one and if it does not correct the problem, that was not it. Owning a ds4 equipped engine comes with the requirement of owning a spare pmd as if it were a spare tire. It is not a commonly stocked part anymore because of the vehicle age, and can leave you stranded.

Definately, the next thing you should do is cleaning All the grounds on your engine. That could be your problem. It is tedious, be patient.

Please post the picture of your obd connector. I have seen some utility trucks with ds4 and an obd1 connector- let's hope yours is obd2 with the ds4 in there.
 
Dang!

The problem is, the only reason the ds4 was invented, was to have more ability to read and control the fuel system. That can only be monitored via obd2.
The obd2 was an emission control requirement mandated in place for regular cars and trucks, that's why they even bothered with the a ds4.

Anything not mandated still got a obd1. It's a common problem for medium duty trucks of all makes from 94-2000. 2001 mandated standardizing.

When working in company fleets, this problem is always weighed out- to retrofit in db2 ip or obd2 wiring harnesses when dealing with diagnostic problems. I always pushed to go db2. After a second new ds4 and a few new pmd gets thrown at a truck, the company would tend to agree.

With the ability of new tunes available, you should talk more to the pro-ds4 crowd here before jumping on my band wagon of db2 ONLY opinion.

Is there anyone on this site that owns another ds4/obd1 combo with insight?
 
Starting to understand, would an OBD2 reader with an OBD1 connector converter read the info from the ds4 as it would from an OBD2 unit. I see converter cables on ebay but did not know even if a reader would give me more info than the paperclip/wire technique
 
Will L. said:
Is there anyone on this site that owns another ds4/obd1 combo with insight?
Click to expand...
My 95 has that combo, at the moment I have no idea of what is wrong.
I have never had a limp mode event. Until a new code/s come up I could only guess.
 
When you say limp mode, do you mean it's stuck in 2nd gear only? Or the transmission has all gears but the engine is limiting power?
 
If you recall from your other thread I mentioned the OPS might be an issue for your fuel supply. I believe that could be the case more so now.
 
Im wondering if its an over boost issue causing the limp mode? Can you test the vac pump and see if its operating? Also the waste gate solenoid can go bad.
 
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