Code 34

[Wing Nut OOA]

34

Injection Timing Stepper (ITS) Motor Circuit Fault

whats the problem? what do i need to do to fix it?

[Wing Nut OOA]

http://www.ssdieselsupply.com/product_162_Stepper_Motor_for_DS4_Injection_Pumps. html


do i need one of these?

[6.5 Detroit Diesel]

Can't help you with a solution, but keep us posted. My dad's 95 has had timing issues since he put a new IP from SSD on his truck.

[Robyn]

Stepper motor fault usually requires the IP to be overhauled.

This is not a user serviceable item.

RC

[Wing Nut OOA]

also getting a code 78 for the turbo wastegate solonoid.

and a code 21 on the ABS side. which is right front speed sensor or open circuit.


could the 34 have been thrown due to the previous owners driving too much with a bad OPS?

[Kennedy]

This code is being set because the pump cannot match actual to desired. It could be a bad stepper or it could just be out of time.

In order to troubleshoot you need to measure timing with a scan tool. You need to look at desired timing and actual timing at idle. Odds are, the actual will be riding high. If so you need to rotate the pump to the passengers side until it can match actual.

Once you have it set or even within 5° you can increase engine speed and watch the desired call for advance and see if the actual falls into line.

[Wing Nut OOA]

sounds like it needs to go into a shop.

Diesel Fuel Injection said they've got hundred or so of the stepper motors laying around and i was welcome to one if i drove up there.

so that will probably be in the next day or two.

the front right speed sensor is 156 from the dealership.

there are some tests i need to run to ensure that is my problem though.



why am i getting a code 78 for the solenoid?

if i unplug it will it go away?

you'd think anyone that went to the spring actuated 92-93 wastegate controller with the adjuster on it would get a code 78 also.

[Wing Nut OOA]

why am i getting a code 78 for the solenoid?

if i unplug it will it go away?

you'd think anyone that went to the spring actuated 92-93 wastegate controller with the adjuster on it would get a code 78 also.


http://i207.photobucket.com/albums/bb315/analog_jedi/lulz/1219818525352.gif

[Kennedy]

How much boost are you running?

[Wing Nut OOA]

the truck is a bone stock 95 6.5.

max boost i've gotten is close to 7 but it normally only goes up to 5.5 or 6.

the reason i asked about the 92-93 spring actuator is because i'm going with one of those eventually, with the adjuster, and i dont want this code to come back.

[JohnC]

As long as you set it so it doen't make more boost than the PCM is expecting the code will not set. Your problem now is most likely the solenoid or possibly the wastegate itself sticking shut.

[Wing Nut OOA]

i know the wastegate isn't sticking shut because sometimes i'll build boost up to 5 or 6 and it immediately bleeds back off to 1 or 0

which tells me my solenoid is releasing vacuum prematurely.


my question is: if i unplug the solenoid will the code go away.


when i switch over to the spring actuator with the adjuster, will i need to leave the solenoid plugged in even though it doesn't do anything or will unplugging it be fine?

[JohnC]

sometimes i'll build boost up to 5 or 6 and it immediately bleeds back off to 1 or 0

which tells me my solenoid is releasing vacuum prematurely.

It looks that way but actually the PCM is releasing the solenoid bcause it cannot control the boost.



my question is: if i unplug the solenoid will the code go away.

Don't bother. Even if the code goes away, you'll never have any boost.



when i switch over to the spring actuator with the adjuster, will i need to leave the solenoid plugged in even though it doesn't do anything or will unplugging it be fine?

I'm not sure. I've heard that the PCM needs to see the electrical load of the solenoid. Wouldn't surprise me.

If you replace the solenoid chances are everything will work as it should.

[Wing Nut OOA]

so all else aside does anyone know HOW the code comes up. is it a lack of response FROM the solenoid?
or is it an improper signal?

if i unplug the solenoid will the code go away...



i will be going to the 92-93 spring waste gate actuator. i wont need the solenoid.

do i need to buy a new solenoid for the code to go away?

do i need to leave the solenoid plugged in even though i am not using it.

i dont want to drive around with the SES light on so if anyone knows the answer to this, thank you.

[JohnC]

The code sets when the PCM cannot control the boost. It releases the solenoid which drops the boost to near zero and it reduces the maximum fuel rate.

If you unplug the solenoid you will have no boost, which is what happens when the code sets, so why bother? You may also set the code because the boost it too low. You can try it, but I think you'll get a code, maybe the same one, maybe not. Meanwhile, you'll have no boost, ever.

Once you get the turbo master and set it to where the PCM is happy, you shouldn't have any codes. Just leave the old solenoid connected so the PCM thinks it's still in control.

[Wing Nut OOA]

i still dont think you understand what i'm saying.


when i get the spring actuator i wont care what the solenoid is doing.

i will be making boost regardless.


i can set it to whatever i want


its immaterial..


what i want to know is how to get rid of the code.


i dont want to buy a new solenoid if i dont have to.

i'm not going to use it anyway.

but if its the only way to clear the code then i will have no choice.

[JohnC]

You will get the code whenever the boost is outside the window the PCM is willing to accept. I also understand, but have not confirmed that the PCM needs to see a complete circuit on the solenoid. When the solenoid fails it usually gets sluggish, but retains the same electrical characteristics, so, as long as you set the boost somewere that keeps the PCM happy and retain the old solenoid, you should not get the code.

If your goal is to run more boost than the pcm is expecting you will need to fool it or reprogram it.

Whatever you're doing, unplugging the solenoid will not help.

Or, you could put black tape over the light.

The solenoid, last time I checked, was $30.00 or so. That's going to be the cheapest fastest way to fix it. If you want more power, programming can increase boost using the solenoid just as easily as the manual controller. More boost without more fuel is just more exhaust backpressure.

[Wing Nut OOA]

lol the abs light had black tape over it when i got the truck.. trying to get away from that.



okay since i'm going to be running about 10-11 boost i'll probably need to just get a new controller.

and the place i found them was 29.99 so you are correct in price.

unfortunately for me its either dealership or internet.

no local parts stores for me.


thanks for the detailed info.

[JohnC]

...okay since i'm going to be running about 10-11 boost i'll probably need to just get a new controller...

Still seems to me you have the cart before the horse. Simply increasing the boost from stock to 10-11 psi has no real benefit. What you should (IMHO) be thinking about is "I want to increase the fuel rate by x% so I'll need to increase the boost accordingly."

A performance chip for your PCM should do both.

[Wing Nut OOA]

i'll look into it. thats a lot more money than i have right now.