• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Run away throttle

1

1995yukon65

Member
Messages
241
Reaction score
2
Location
Baltimore, MD
Hey guys, im new to this site and need your help (dont say search either cuz i just did). I just went to take my truck for a drive after replacing my brakes and for the first time in months it started revving up and down btwn 700 and 1500 rpms. It stopped for a minute the just revved up on its own and wouldnt stop til i cut the key off. BTW its a 1995 yukon 4wd s vin engine. In the past year i have replaced the following parts... alternator, starter, pmd (ssd heatsync(waiting on money to get it off the intake please dont yell lol)), IP, LP, turbo, egr solenoids, wastegate solenoid, injectors, driverside injector lines, belt, tesioner. Injectors and lines were done last month. Thank you for your help. My truck needs it so it dont get replaced with a cummins :mad2:):h:thumbsup:
 
1995yukon65 said:
Hey guys, im new to this site and need your help (dont say search either cuz i just did). I just went to take my truck for a drive after replacing my brakes and for the first time in months it started revving up and down btwn 700 and 1500 rpms. It stopped for a minute the just revved up on its own and wouldnt stop til i cut the key off. BTW its a 1995 yukon 4wd s vin engine. In the past year i have replaced the following parts... alternator, starter, pmd (ssd heatsync(waiting on money to get it off the intake please dont yell lol)), IP, LP, turbo, egr solenoids, wastegate solenoid, injectors, driverside injector lines, belt, tesioner. Injectors and lines were done last month. Thank you for your help. My truck needs it so it dont get replaced with a cummins :mad2:):h:thumbsup:
Click to expand...


Is the truck still acting up? give us your particulars, like how old is the Injection Pump (IP) and other items did you recently fuel up, remove the battery cables or replace any thing other than what you mentioned. The folks here can help you diagnois it you just need to give us all theh little details that make the whole picture. ):h
 
Welcome!!!

My suggestion is to DO Diagnostic Troubleshooting Checklist on the sticky.

By the way, most of us will yell because the one on the intake is not a good location. All you need is an extension cable, we have vendor here that sell that cable (pmdcable.com). Who knows, that may be the cause of your problem.
 
this probably is not it but the engine coolant sensor, as it can cause the engine rpm to vary between 450 and about 1200, when mine failed it jumped a few times then stuck at 1150. just far off idea that happened to me.
 
The IP, LP, and turbo have less than 5000 miles on them, PMD was replaced 8 months ago (Im ordering the cable in the next couple of days from pmdcable.com) im also ordering a new pmd (dtech) and gonna mount it in the bumper, injectors are only 2 weeks old and same with the injector lines. It hasnt had a problem since i posted last night (maybe it realized i wasnt kidding about replacing it with a cumins...lol) I have checked that i have fuel flow by opening the drain valve(steady flow of fuel immediately) I forgot to mention that i also replaced the APP sensor(fuel pedal) around the same time that i replaced the pmd. Is there a chance that the app is goin up???
 
also i was just kidding about the yelling cuz ive been meaning to get the pmd moved just nvr had the chance. guess i gotta do it now.:D
 
If you are going to buy a PMD cable and PMD might be worth it to go Heath. 7 year warranty. Mine's going on 3 yrs, no problems.
 
As mentioned the solenoid can do just what you describe.
Now the PMD can also do a hunt, hunt hunt and then runaway.

Drop a fresh DTECH PMD on your beast and recheck things before yanking off the IP

I have seen this sort of failure. I was testing a handful of used PMD's and had one that did just what you are reporting.

If the PMD goes sour it can run the thing up against the governor and then the ECM will drop the shutoff solenoid to kill it usually.

MGW
 
Good Idea to get a new PMD properly relocated and then isolate other problems after that. Truth of the matter is, if you plan on keeping the truck, you need a fresh, remote mounted PMD to rule out that.

Should get yourself a Boost-Bolt too from PMD-Cables, make it really easy to install that boost guage that you want :)

Question to the armature, would that throw a code?

I also hope you have a warranty or something of that nature if you have an IP problem w/5k mi.
 
Missy Good Wench said:
As mentioned the solenoid can do just what you describe.
Now the PMD can also do a hunt, hunt hunt and then runaway.

Drop a fresh DTECH PMD on your beast and recheck things before yanking off the IP

I have seen this sort of failure. I was testing a handful of used PMD's and had one that did just what you are reporting.

If the PMD goes sour it can run the thing up against the governor and then the ECM will drop the shutoff solenoid to kill it usually.

MGW
Click to expand...

That's what mine did. While driving it just took off :eek: I guess you could call it a runaway. I shut it down before she blew. Not a good feeling at all!!:nonod:
 
when it does this it normally on revs up to around 3000 but only for a moment, it normally stops after a minute or two or when i turn off the ignition.
 
The SSD PMDs as of like a year ago are the Dtech type, and I wouldnt think it would have gone bad yet, but the grounding on the side of the heatink through the intake bolts might be an issue. See if that is loose at all, and run a ground wire from there back to the original IP ground, or I run mine to the battery engine ground just below. SSD also says to tighten the screws every 3k miles.

Do you tow much? If not then I wouldnt think your PMD could have gotten hot enough to be cooked. Always good to have a spare though, can pick a new one up on ebay for like $180.

Dont rule out the simple coolant sensor either.

I have one ECM E-PROM chip that when I put it in it will rev up and down for the first few seconds every time until it figures something out, I dont use it to drive, but was testing it.
 
I just read that last post where it goes to 3k RPM! that must be scary...waiting to see it drop....has to be something like the PMD then to be able to input that much fuel. unless the ECM is going crazy and telling the PMD to do it, but not usually the issue.
 
x3, WOT in heavy traffic in the middle of Chemical Valley, while everyone is getting off work. NOT FUNNY!

Edit: unless a cop pulls you over after, and you try to explain to him your throttle stuck.
 
Yea i got pulled over a couple of months ago when that happened and the cop told me that i was full of shit. Needless to say tho hes no longer with the force after a call to his boss. But i do agree it is scary as anything having that happen in the middle of heavy traffic. Got PMD and extension ordered today will get everything mounted and let you guys kno what happens, thanks again for your help:thumbsup:
 
You must log in or register to reply here.
Back
Top