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1994 turbo 6.5 dumb question don't laugh

W

wiggle

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High guys I'm new and dumb to diesel's....My dumb question is the black box just below the master cylinder is it and ABS electronic controller....That's my guess.....Being trying to keep this old bird going as it will run down the highway and just die about 10 minutes everytime..Lift pump new ,lines new,ops new,iac new,fuel driver new,cts new,injection pump new +timed,...into the wiring now checked app tests good,glowplugs test good,PCM all pins good and connectors tights all grounds clean and tight.....just have no more ideas
 
wiggle said:
High guys I'm new and dumb to diesel's....My dumb question is the black box just below the master cylinder is it and ABS electronic controller....That's my guess.....Being trying to keep this old bird going as it will run down the highway and just die about 10 minutes everytime..Lift pump new ,lines new,ops new,iac new,fuel driver new,cts new,injection pump new +timed,...into the wiring now checked app tests good,glowplugs test good,PCM all pins good and connectors tights all grounds clean and tight.....just have no more ideas
Click to expand...

Ensure your using an acdelco oil pressure switch.Other brands are not as durable.
 
I forgot to add the crank sensor was the first replacement done.....ops is delco...I'm used to working on gas so this is a little different of coarse.....all this work was done by someone else and I'm stuck here trying to fix it up.....Anybody now if the black box is in fact a ABS control module or some other kind of module.......one strangle thing with this truck is it has a MAP sensor hooked up to the wiring but no solenoid or vacuum attached to it....it only has one solenoid with wastegate and air pump hooked up
 
wiggle said:
I forgot to add the crank sensor was the first replacement done.....ops is delco...I'm used to working on gas so this is a little different of coarse.....all this work was done by someone else and I'm stuck here trying to fix it up.....Anybody now if the black box is in fact a ABS control module or some other kind of module.......one strangle thing with this truck is it has a MAP sensor hooked up to the wiring but no solenoid or vacuum attached to it....it only has one solenoid with wastegate and air pump hooked up
Click to expand...

That would be the baro sensor for altitude. Not that the ECM does anything with it, but, it is there. Decoration that when removed trips a code... Not part of your current issue.

Yes the black box you ask of is a ABS unit for the rear wheels and NOT part of your current problem.

Stalling after 10 min.
Sounds like you have thrown parts at it without knowing why. This gets expensive and a good chance of a bad replacement part making things worse. I suggest we troubleshoot it before buying more parts. An old IDI diesel like ours, unlike a FI gas engine, will run a short time with fuel system problems then stall out. (Generally if anything fuel related quits on a FI gas engine it is not going to start again for any amount of time till it is fixed.)

Where is the PMD located? Where did you get it and is the 'extension cable' made in China if the PMD is relocated?

Pull a sample of fuel from the water drain into a clear container. Smell for bad smells, gasoline, and let it sit for 10 min. Did water settle out? Assuming the fuel is good we continue.

Put a clear 1/4" line off the IP to the fuel return rail on the front of the engine. You want to check for air bubbles. Especially after the engine stalls out. You also want to check fuel pressure at the water drain. "0" to whatever gauges are NOT the proper tool for the job. These systems will pull a vacuum and boil diesel to a vapor lock state with a kinked hose, plugged tank sock, etc. and your gauge needs to show this if it is happening. It needs to be a pressure/vac combo gauge.

Rev the engine to the point the governor holds the max 3600 RPM and check for some fuel pressure at that RPM. The IP bypasses a lot of fuel esp at high RPM. This will help eliminate plugged tank socks, kinked hoses and other fuel system restrictions.

Any codes? Use a paper clip to read out the codes if you need to.

Simply put you are running 10 min until you run out of fuel or something electrical gets hot and quits. Aka fuel system restriction or PMD if I were to guess with grounds, and ignition switch/misc wiring coming in 2nd.

I assume, but, have you looked at the fuel and air filters?
 
The guy who owns this is in love with it......so many things have been replaced it's hard to remember....fuel lines,new tank,ip,filter....I tried the fuel shut off solenoid....bench tested it seems fine even hit it with a heat gun to see if it would breakdown....worked as it should but the spring seems weak,only 7lbs needed there eh......when see shuts down it's like the key was turned off...sometimes starts right up but in Limp mode......my old snap -on brick won't comunicate right with this truck since it has a number 5 chip instead of the #9 chip
 
NO CODES The new PMD is on the intake...no extra harness ...as installed by someone else.can't till you about it.....I have replaced nothing I have just been checking out everything looking for a problem.....Monday I will pressure test the fuel system and drive it around the shop yard till it quits,will also test the fuel for water,or something else As far as I have been told the OPS was just replaced as the fuel tank, new lines,and lift pump....along with the crank sensor.....I appreciate the tip on running 3600 rpm as I would like to rule out the sock and lines......I was told there was also a lot of air in the lines the old return line was plugged up they released air out by the filter many times when it just quit....and also that the new PMD solved that issue.....Doesn't sound right to me.....Anyways thanks any more suggestions would be greatty appreciated.....Will let you guys know tomorrow what I find want it out and gone
 
May be just need a good air bleed?

You have to test everything, though.

New parts do not mean they are working as intended.
 
PMD new with in a month.....just hanging there....ground is hooked up don't believe any die grease on it..ifin I remember right it's gray...at shop not here
 
Yes the so called expert who was replacing everything left it like that.....the owner brought it to me to sort out....my my carpy work boy...I think I'm also going to check the new fuel filter out just in case it's wrong.or if bottom strainer is missing
 
Need to get that pmd mounted to heat sink.... that may be the issue. Running a pmd with no heat sink will fry them. I would get a new pmdcand heatsink.... check it the one from Leroy diesel.
 
x2, PMD last about 2-5 minutes without heatsink, some only last 50 sec.

You may want to get a new one or get it warranted with the people who fixed it.
 
JMJNet said:
May be just need a good air bleed?

You have to test everything, though.

New parts do not mean they are working as intended.
Click to expand...

JMJNet said:
x2, PMD last about 2-5 minutes without heatsink, some only last 50 sec.

You may want to get a new one or get it warranted with the people who fixed it.
Click to expand...

Two rules for a 6.5 diesel:
1) New parts are not always good parts. Start troubleshooting over after a part replacement did not fix the problem.
2) Do the job properly the first time or you will have to make time to do it over.

At this point the PMD has shut down due to overheating. It is ruined. Sure it will run, but, it has trouble down the road for the owner who will be bringing it back... Warranty should not cover improper install - that is missing the heatsink. You need to get a new one with a heatsink and a quality cable. LeroyDiesel.com has the Made in USA cables that I haven't been able to kill.

You are also looking at possible re-work of what others have done. If they dropped the tank and replaced the fuel pick up assembly it will have the wrong sock on it. The factory sock has a bypass valve in it for cold fuel etc. The replacement Communist China cr@p doesn't. (maybe a dealer part would, but all aftermarket doesn't.) You will need to eliminate the sock and use a Walbro lift pump with a built in screen or a pre filter before the lift pump of some kind.

I would still check for air in the system after you take care of the PMD just to be sure you don't have multiple issues before it goes out YOUR door.
 
Lots of head way with this old beauty......computer c1 power wire was broken at firewall.ran new wire......starts great now with pump relay disconnected....new pump relay going in tommorrow.....all the other parts test out even the PMD.....it's back where it lives for now..till extenda kit comes ....it's only 6 bolts on intake anyways......got the list of parts put in within the last 2 months......you name it probably has it.......the shut down was the C1 computer power wire rubbing threw at the firewall.....you have to watch out for bumps in the road with a wire that bad I told the owner lol.....pump relay tested flacky also.......By the way the BARO{aka} MAF is on the intake.....and the MAP is on the firewall electrically hooked up but no vaccum or sensor attached still strange to me
 
Hay guys thanks for the help .....the old beauty has been running perfect since also the trannie issue has been fixed the C1 power wire replacement did that also......it had issues that weren't explained to me .....same computer circuit as the APP and trannie go figure....ifin your looking into it it's the connector closest to the firewall the pink wire C1 on the blue holder....it's marked on the blue holder.....right under the glove box ....4 bolts to take the glove box out......pop a 1ohm 10 watt resistor between your negative battery cable and battery post {neg cable disconnected from battery} then you can probe safely at the computer......The owner risked a 240 mile drive and had no problems.......guess I got lucky eh lol
 
did you do anything about the PMD? if not, expect a call for a car trailer and a come along.

I will cheap out on a PMD, but only with two conditions: its brand spanking new, and I snuck up on it on ebay and got it cheap, OR its a used kit that has been in the bumper its entire life. otherwise, you NEED to buy a NEW one and mount it on a heatsink in the bumper. I buy my heatsinks from leroydiesel.com

good luck!
 
wiggle said:
Lots of head way with this old beauty......computer c1 power wire was broken at firewall.ran new wire......starts great now with pump relay disconnected....new pump relay going in tommorrow.....all the other parts test out even the PMD.....it's back where it lives for now..till extenda kit comes ....it's only 6 bolts on intake anyways......got the list of parts put in within the last 2 months......you name it probably has it.......the shut down was the C1 computer power wire rubbing threw at the firewall.....you have to watch out for bumps in the road with a wire that bad I told the owner lol.....pump relay tested flacky also.......By the way the BARO{aka} MAF is on the intake.....and the MAP is on the firewall electrically hooked up but no vaccum or sensor attached still strange to me
Click to expand...

Electrical is fun like that. Glad you found a major issue.

By the way that's not correct. It will make troubleshooting easier if you have a clear understanding of what you are looking at - you did ask.

BARO is barometer. Where do you suppose a good place to measure that is? It is measured by a sensor on the firewall. As it is simply measuring atmospheric pressure it doesn't need to be hooked up to anything. It most certainly isn't MAF! Some engines use the MAP to measure Baro when it is possible to do so like key on engine not running, WOT, etc. A dual purpose MAP/Baro sensor would be hooked up to the intake. Most older 6.5's have 2 separate sensors: A MAP on the intake and a separate BARO sensor on the firewall that is only plugged in to a electrical connector and nothing else. MAP/Baro sensors look identical. This is why you are looking at a sensor that isn't hooked up to anything - the BARO sensor comes from the factory like that on 6.5 diesels.

MAF is Mass Air Flow. This is a round sensor on the intake tube by the air filter that measures air flow. Corrected with temperature it gives the Mass of air going by it. Offhand only the 1999 or so years has one on a diesel. The 1994 did not come with a MAF sensor from the factory. Mass air flow is also a type of fuel injection system using air mass as opposed to a SD: Speed Density system.

MAP is Manifold Absolute Pressure. Measures the vacuum or boost in the intake manifold. Can be used to take BARO readings saving the cost of a second sensor. Turbo's make this dual purpose more difficult. So some designs have separate sensors.
 
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