Shuts off while driving - Stalling

[Eddys]

1994 Blazer Silverado with 6.5TD. It happened a few times the truck will just shut off while driving. It will start right back up again and will not trip the service engine soon light. The truck runs fine besides that. The problem is intermittent. Has anybody seen this or experienced this problem?

[ 12-17-2004, 05:37 AM: Message edited by: JohnC ]

[More Power]

This is a somewhat common problem that has been discussed many times here in this 6.5L Turbo forum. A search for the word "stalling" in this forum will yield lots of reading on this subject.

Jim

[RANCHMAN]

THAT STALLING PROBLEM IS ONE OF THE THINGS THAT HAPPENS WHEN THE DS4 SOLENOID DRIVER STARTS TO FAIL. THAT'S WHAT MY TRUCK WAS DOING AND REPLACING THE DRIVER FIXED THE PROBLEM. CHECK AND SEE IF YOU ARE GETTING A CODE 35. THIS PROBLEM HAS BEEN DISCUSSED QUITE A BIT ON THIS FORUM. CHECK THEM OUT

[ucdavis]

Given the age/mileage of the rig, could also be the ingition "switch" which is not the key switch, but a device in the steering column below the key switch. It gets worn, & breaks contact of the 12V ingition circuit. If you can wiggle the steering column & fix the problem, it is the switch. It gets worse over time, due to continued wear.

[Barry Nave]

The new,# 2 SOL-D has been working great.

[DeezlStinson]

Howdy all,

Yeah....Mine has been doing this for last couple of weeks. Today it finally would not start at all. (after I get it towed home) I'm going to do a little electrical trouble shooting. I have a PMD to install but I want to be sure that's what the problem is. I got DTC-13 and DTC-36 (1994 model)

I still think it's a 12v supply problem...possibly the ignition switch or associated wiring. If not I'll replace the PMD. I'll also probably have a look at the transistors in the PMD..I have a hard time believing that 2 PNP/NPN switching transistors and a few associated parts should cost upwards of $300 or more. We are really getting ripped off on thse things.(especially since they are so poorly designed!)


More to come!

Cheers (?)

Rick

[ 12-27-2004, 09:00 PM: Message edited by: DeezlStinson ]

[Chad Mac]

I feel like a professional on this subject because I have fixed stalling problems on my truck on 4 seperate occasions.

The first time was the ignition harness that was mentioned earlier. When mine went out it would stall while driving and no dash lights would come on. I could work the key switch back and forth til the dash lights came on and it would start right up. New ignition harness and problem solved.

The second time was the infamous PMD/FSD. When mine went out it would stall while driving and sometimes start right back up, sometimes I would have to crank on it for a while. New PMD/FSD and problem solved.

The third time was the also infamous OPS. It would only stall shortly after restart when the truck had been driven and shut down for a short time period and would require some cranking to get it going again. New OPS and problem solved.

The fourth time was the in-line fuel lift pump that assists the injection pump. Symptoms were serious hiccups under acceleration and stalling after startup with lots of cranking to get it going again. My lift pump sounded like it was working fine (humming when the key was turned forward and when the truck was running) but all it was doing was making noise and not pumping any fuel. New fuel lift pump and problem solved.

I don't know how to explain it but I love the truck. My next truck will be a 6.5 also. I guess because I know the engine so well that I feel like I can diagnose and fix almost anything on it now. Good luck with your problem!

[nealpellecchia]

I feel like a professional on this subject because I have fixed stalling problems on my truck on 4 seperate occasions.

The first time was the ignition harness that was mentioned earlier. When mine went out it would stall while driving and no dash lights would come on. I could work the key switch back and forth til the dash lights came on and it would start right up. New ignition harness and problem solved.

The second time was the infamous PMD/FSD. When mine went out it would stall while driving and sometimes start right back up, sometimes I would have to crank on it for a while. New PMD/FSD and problem solved.

The third time was the also infamous OPS. It would only stall shortly after restart when the truck had been driven and shut down for a short time period and would require some cranking to get it going again. New OPS and problem solved.

The fourth time was the in-line fuel lift pump that assists the injection pump. Symptoms were serious hiccups under acceleration and stalling after startup with lots of cranking to get it going again. My lift pump sounded like it was working fine (humming when the key was turned forward and when the truck was running) but all it was doing was making noise and not pumping any fuel. New fuel lift pump and problem solved.

I don't know how to explain it but I love the truck. My next truck will be a 6.5 also. I guess because I know the engine so well that I feel like I can diagnose and fix almost anything on it now. Good luck with your problem!

Ok, my 1993 6.5 has a severe suction when you take off the "new" vented gas cap. The others too. It didn't have this before the last few mos. or I would have noticed it I think. Well when empty it's always like normal right? Anyway I've fixed suction leaks at the fuel mgr., top return hose, new hoses and clamps in between. It's run like a champ! with the higher fuel pressure. And then dogged 2.5 hrs. into a trip, with even a backfire. I pulled over and loosened the cap...left it loose, Then it takes fuel normally again. The best answer I've gotten is that it's a symtom of a clogged sock; that high suction. Is this true?? Before I spill for a injector pump I want to cover everything. Air is coming in again. Stalled cold starting and hot starting. Both require bleeding the air out of the system. Tank is suspect. Clogged bi-pass valve? holes in lines back there?? Anybody know some stuff about this area?

[More Power]

Ok, my 1993 6.5 has a severe suction when you take off the "new" vented gas cap.

I suspect you meant diesel cap, but it's helpful that everyone knows that there is a big difference between a fuel tank cap made for a gas powered truck versus a 6.5 diesel truck. You must specify a "diesel" fuel cap when buying a replacement.

According to GM, a diesel fuel cap should vent when internal fuel tank pressure exceeds 2-psi or 1" vaccum. Gas caps are generally not vented, which would create huge vacuum as fuel in drawn down in the tank.

Jim

[Firstoneman]

Greetings:
I have a 94 Suburban, auto trans. Drove this from Cali to Michigan Jan 2015. During the trip I developed a stall problem leaving Denver. But it restarted and I went on my way. Later it also gave me a check engine signal at higher speeds (70-73mph), slow down 5mph and the light went out. Sometimes it would show up at 65mph - but go away just by letting off accelerator. I did have some bucking, like not enough fuel, when climbing a few grades leaving Cali towards Utah and in Colorado. I made it to Michigan. Once I got here, I had a situation where it would start in the parking lot and stall after about 12 secs of running. It kept doing this for about 10 tries. I went home for the evening, headed back the next day and started it up and it kept running - headed back home only ¼ mile away. Made it. After that it stranded me in another lot. I had to travel out of US for 7 months so it sat there. I haven't tried to start it since I returned because it is 2.5 hours away. I've read a number of posts and I think it is either a lift pump, PMD/FSD, or maybe even the fuel solenoid. In this thread, and the sticky on the PMD, I do not see much in recent years on the matter.

I'm going to buy some parts - that way, when I do go to that part of the State, I can fix it. I am tempted to just try the PMD/FSD but I don't want to short it if it's fuel solenoid. What brand PMD is recommended these days? Also, how about the fuel solenoid…what brand is best? Is the fuel solenoid the same as the "fuel cut-off solenoid"? If they are separate products what is good brand for the "fuel cut-off solenoid"? And what brand for a lift pump? Thanks for help. This has been a learning curve and a good experience so far.

Cheers!
David

[Lug]

I would bet on the PMD. Unfortunately the only way to really eliminate the PMD is to put one in and see if the problem goes away. Also check your grounds and power connections. The 6.5 tends to be voltage sensitive. The first time My 94 was doing this I bought a Heath relocation PMD and that worked for several years. The next time it started to do this it turned out to be the power connections on the firewall terminal strip were not tight enough and had corrosion buildup. A quick and cheap shotgun shell is to take those connections off (one post at a time) and clean them up and reinstall them. Use some sort of grease on them to seal the terminals from further corrosion. I used Dow Corning DC-4.
Justin

[DeezlStinson]

I have had wiring problems, lift pump and PMD so far. I've never had the OPS fail (Optical sensor?) Nor have I had a problem with the ignition switch. Those are probably next huh?

This time it was the PMD. I think this is going to be it for me. I'll either go to a mechanical injection pump or I'll get rid of this thing and get a New pickup!

Nearly 11 years and 138000 miles is long enough to keep any vehicle!


Of course this is the place where people cry about their problems a lot!

I wonder how many 94-99 GM diesels had NO problems by comparison? The people with no problems just drove them until they got tired and got something else.

Cheers everybody!

Rick

Originally posted by Chad Mac:
I feel like a professional on this subject because I have fixed stalling problems on my truck on 4 seperate occasions.

The first time was the ignition harness that was mentioned earlier. When mine went out it would stall while driving and no dash lights would come on. I could work the key switch back and forth til the dash lights came on and it would start right up. New ignition harness and problem solved.

The second time was the infamous PMD/FSD. When mine went out it would stall while driving and sometimes start right back up, sometimes I would have to crank on it for a while. New PMD/FSD and problem solved.

The third time was the also infamous OPS. It would only stall shortly after restart when the truck had been driven and shut down for a short time period and would require some cranking to get it going again. New OPS and problem solved.

The fourth time was the in-line fuel lift pump that assists the injection pump. Symptoms were serious hiccups under acceleration and stalling after startup with lots of cranking to get it going again. My lift pump sounded like it was working fine (humming when the key was turned forward and when the truck was running) but all it was doing was making noise and not pumping any fuel. New fuel lift pump and problem solved.

I don't know how to explain it but I love the truck. My next truck will be a 6.5 also. I guess because I know the engine so well that I feel like I can diagnose and fix almost anything on it now. Good luck with your problem!

[rjschoolcraft]

My uncle has a 96 with 5-speed that has not given the first problem. It has somewhere near 70,000 miles and is completely bone stock. He has towed a travel trailer with it to NASCAR races and uses it around the farm. He's the reason I bought a 6.5 in the first place.

[DeezlStinson]

Hi Ron,

We have to remember that this is the place where mostly people with problems came for help. There are probably thousands of people who had no problems at all. The average person keeps a vehicle 3-4 years, 60,000-80,000 miles and either trades it in and/or sells it and gets another one.

It's "us people" who choose to keep them to well over 100000 miles (11yrs in my case) to squeeze every last penny out of them (because it cost much to begin with!)


We are lucky to have a dedicated group of people like Jim, Lee and others who pulled us all together so we wouldn't be completely dependant on the dealers.


Happy New Year to you all!


Regards,

Rick

Originally posted by ronniejoe:
My uncle has a 96 with 5-speed that has not given the first problem. It has somewhere near 70,000 miles and is completely bone stock. He has towed a travel trailer with it to NASCAR races and uses it around the farm. He's the reason I bought a 6.5 in the first place.

[chevss442]

I am going to relocate my FSD/PMD and put it on a cooler this weekend. So far it is working fine, but I want to try to avoid problems. My question is, is there a way to remove it from the injection pump without having to remove the intake manifold?

Thanks!

[BILLYDIESEL]

I am going to relocate my FSD/PMD and put it on a cooler this weekend. So far it is working fine, but I want to try to avoid problems. My question is, is there a way to remove it from the injection pump without having to remove the intake manifold?

Thanks!

REMOVE A/C COMPRESSOR,MARK YOUR INJECTION PUMP TO YOUR TIMMING COVER AND ROTATE IT TO PASS SIDE.USE A T15 TORX AND A 1/4 IN WRENCH
TO LOOSEN ALL TORX SCREWS."THE TRICK IS TO GRIND DOWN THE TIP OF
THE TORX BIT TO MAKE ENOUGH ROOM FOR YOU",AS SOON AS YOU SE THE
ACTUAL HEAD OF THE SCREW AND THE DRIVER MOD COME FLUSH "STOP"
THATS ALL YOU NEED TO GO.THEN GIVE THE MOD A COUPLE TAPS AND IT
WILL COME OFF.

[andro70]

Can anyone tell me what the part number is for the ignition switch that has been discussed regarding stalling? If nobody knows the part number a picture or description of what it looks llike.

Thanks

[JohnC]

Do I have the same problem?

I don't think so. I have moved this post to a new thread: http://www.thedieselpageforums.com/t...ad.php?t=24299

[jilaroo2]

Untill last week I had intermittent "no start"problems ( hot or cold ) .
I installed a brand new remote FSD last week.
Drove it arround for a week ( close to home to make sure I would make it back) and no more problems.
Today I took it further away and guess what happened !
It wouldn't start when hot.
After a while got it started and then on my way home it stalled on the freeway!
No way to get it started again ! Switched to other PMD same problem.Had it towed home and in my driveway I tried it one last time (towtruck was still there)and it fired right up !
I noticed some problems with my ignition , so I'm thinking of changing the ignition harness.(partnumber:#26075995 ) $88 at www.rockauto.com.
Is there something else I should check before doing this and do I need to replace other things?
Any of you guys live near San Jose, CA.
I don't know how to keep this engine running.
Totally unreliable IMHO.

[skyway9517]

I have a '96 6.5TD with original engine/trans and 210,000 miles on it. I had the same problem, going down the road minding my own business, and the dumb thing just shuts off. No SES code either, you pull to the side of the road and it would usually start up in a minute or so... When the PMD starts becoming intermittent, it's getting ready to puke out on you at what is usally a most inoppertune time. Currently, I'm on my 3rd Stanadyne PMD aka FSD and they cost around $350.

The original mounting location of the PMD was on the side of the injector pump, down in the rocker valley under the intake manifold... Bad place to put an electronic module (heat and electonic module = trouble). The second one I remote mounted the module to the top on the engine and attached it to the upper intake, that one ultimately died too!! For the 3rd one, I went to SS Diesel (www.ssdieselsupply.com) and bought the BIG heat sinc, then to Kennedy Diesel (www.kennedydiesel.com) and bought the 72" harness extension and remote mounted the entire unit in an area that I could keep cool. I put mine in the cab of the vehicle right under the floor vent on the transmission hump. Did that 3 months ago and been working fine ever since through the summer heat!! Not pretty, but gets the jobs done by keeping it out of the multi-hundred degree engine compartment)

We ALL hate to throw $$$$ at "What if's" but this worked for my truck and problem... Just my 2 cents