ok, here goes.

not very familiar with the 6.5 myself, posting this for a friend who was helping me out tonight.

specs: 1995 i believe chevy 6.5l auto. only mods are air filter and #5 fuel resistor.and a new PMD (2 or 3 weeks old)

Tonight we towed out my wheelin rig, so prolly at least a 9k or so load behind it and about an hour drive each way, trip out went fine but on the trip back cruising down the freeway doing 60-65 in od the motor just shut down, coasted about 4 miles with power nothing and pulled off to the side. tried to restart and it fired with a bit of struggle and idled fine, but had zero throttle control push the pedal and nothing, put it in gear and it dies. after a few tries and looking things over it wouldn't even start anymore.. a few guys passing by towed the whole mess off the freeway and helped us get home for the night.

where to start for troubleshooting this? neither of us really know anything about this motor, and the truck is fairly new to him as well. I know this is most likely covered somewhere but i kinda gave up on search (look at the time) and want a starting point to go over the truck from whenever we all manage to wake up later today


Thanks a lot!

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ok, after a few hours of sleep i'm back to looking into this. *sounds* like it could be an issue with the new PMD but what's throwing us for a loop was the lack of throttle control when it did start.

right now it cranks and puffs out smoke like it's just to cold for the motor to light.

I do remember twice yesterday a miss to the motor, like ignition dropped out, kindof a minor hiccup, not sure if anyone else noticed it.. could be the stepper motor that runs the drive by wire throttle?

will be checking for codes but i don't ever remember the light being thrown untill it died.

 

you rarely see the stepper motor dying but the optic sensor sometimes fails and thats what tells the pcm where the injection pump is as far as timing and speed. maybe start there

 

Ok. played with it a bit tonight.


spent and hour and tore the pump apart. the optical sensor appears good but looks can be decieving. it was slid completely to the drivers side so i put it back in and moved it a C-hair over to the pass side. put it all back together and it fired up! but Very Very loud and clattery.. too much timing?

also hitting the accelerator pedal had no effect, it stayed at idle with a little surging here and there so it got shut down. ran for maybe under a min due to the loud sound.

but it fired now, it wouldn't even do that before.

 

I have sorta the same problem pulled the top off of the fuel pump cleaned the return lines getting fuel when does start it may run for 1 or 2 minutes and die as if you turned the switch off. Any ideas I really could used some help.
Thanks JRV

 

ok, codes we pulled off right after it happened.

18 19 84 79 86 63 62 57 54 49 42 39 34 25 22 I told em to play the lottery with those !

cleared the ECM and after getting it running briefely and bad we have these codes currently.

18 : crank signal circuit?

35: IAC or idle controll circuit shorted

doing more reading and any input is helpful, figure I keep adding info as we work through it so it may help others .

 

if the pcm doesnt know what the speed of the crankshaft is and idle control circuit has a short in it i think the computer is trying to protect the engine. maybe a new crank sensor and a clean circuit and it might run

 

Well,

He managed to find codes directly from a 1995 chevy 6.5 somewhere.

they both relate to timing, bad pump crank signal, and pump crank signal pulse width too short, something along those lines. i"m thinking that would relate directly to the optical sensor in the pump

Also to note, he was running 1/2 tank of dino diesel and half tank of B20 after the fact we hear standyne only recommends b5? could this cause any trouble? I hear of people running higher mixes without any problems..

 

the bio diesel shouldn't cause any problems but that's hard on the parts inside the pump, bio diesel is more solvent like, it'll clean your fuel system wonderfully but it's also pretty harsh on your pumps guts and your injectors, just stick with dino fuel, i know it's not as "good" for the environment, but it'll keep the truck running longer

 

haha yeah, thats a bummer cuz it's a whole $0.25 cheaper than dino.. haha my 12v LOVES it

i'll update this after we get some parts to swap out and test.

anyone else ever have the throttle not work tho?

 

well if it's cheaper, run it but remember a lot of fuel lines are made of rubber, and that bio fuel is corrosive