Engine Bucking

[J. REUTER]

Just returned from a 400 mi trip towing 5k load and the engine was bucking all the way. Most noticable between 50 and 65 mph , seemed to stop above 65mph. Thought there might be water in the fuel so I drained the lift pump and didnt notice any water in the discharge. Anybody had a similar problem? Truck has 19k on the clock.

 

[Boost]

Mine has the same bucking. It only happens at between 1/2 and 3/4 throttle under acceleration. Clears up at WOT. Unhooked the EZ with no change. Fuel pressure good. Bad TPS maybe?? Someone said maybe a "flat spot" in the injection pump?? I would love to get it figured out.

 

[KWIKKURT]

Same problem here. Sometimes it does it other times it is fine. Usually will only buck once or twice then clear up.



Twice now afetr washing the CTD at the car wash it will completely shut down during acell then come back at idle. Clears up after a bout ten minutes!... Any Ideas??

 

[Ram4Sam]

Map sensor??

A few weeks ago while on a short trip pulling my fiver, I had pretty much the same symtoms as you guys. I lugged it down pulling away from a light and it bucked a few times and went into a brief limp mode and got the CE light. I checked all the obvious connections, restarted and ran fine for a few days. Then, almost home, it started bucking again. It idled fine and full throttle was okay, just an intermittant midrange stumble. I got code 0237, which is for low map sensor voltage. Dealer put in new map sensor, been fine ever since.



Sam

 

[1BIG44]

Mine Too

J Reuter



I just got back from a 4000 mile trip pulling the 5'er and my truck started dulling the same thing that you are describing. Mine was most noticable at 60-65 mph above that it seemed to disappear. I changed settings on the EZ , made no difference. Finally, I pulled the box and it didn't happen. Does yours do it without the box. I talked with the guys at edge and they are sending a new EZ, I don't think that is my problem, but I will try. I suspect some sort of sensor is bad, but I'm to ignorant to know which one to start with. Hopefully someone can give us idea. Keep us posted with what you find out.



Wes

 

[WCrovo]

I had a similar problem while towing with my 99 auto. Turned out to be the tourque convertor. It feels like a engine miss but its not. I see some experenceing the problem are sticks. My stick hasn't missed a beat.

 

[J. REUTER]

I unpluged the EZ today and the bucking dissapeared, along with that seat of the pants weeeee. Going to take it in to my 5star and let em check for any codes. I have a feeling it may be a sensor problem.

 

[RustyJC]

OK, guys, are you about to rain on my parade? I just installed the Edge EZ last weekend, and am really enjoying the extra horsepower and torque. Based on the improvement in unloaded performance, I was looking forward to getting the 5ver hitched up for the next trip. Am I now to understand that this "bucking" problem is somewhat common for the Edge EZ in heavy towing applications? Should I be dreading instead of anticipating the next trip with the 5ver?



Rusty

 

[Boost]

Rusty



You will love how much the EZ helps while towing!! My problem does not go away when I unhook the EZ. It is now at the dealer. I am lucky in that the local 5star has a GREAT service dept. I will post what they find.

 

[Runaway]

I have the same symptoms when pulling my 5ver. BUT... my question(s) was it windy that day??? Pulling into the wind???? Quartering the wind??? I only get these symtoms between 1650 - 1900 rpms (there abouts) in 6th gear, and gradually accelrating. Harder on the throttle and symtom disappears. But this is only when the wind conditions are head on/quartering at 25mph or higher (wind that is).



One other thing, pull your fuel filter and replace. First time I had these symtoms, I found my fuel filter all crudded up with only 6000 miles on the truck.

 

[1BIG44]

Runaway I too first thought it was just the wind causing this. But once we got home and I pulled the familiar old roads it happened no matter going into the wind or with the wind. I first suspected my fuel filter but I have a sender before and after filter, and the readings are the same. Maybe someone will get it figured out.





Rusty

Not to worry the EZ is great when towing, I sure missed mine when it was unhooked. I don't think this was the cause of my problem, but I'm also not making boost like I should so I thought I would try a new box.

Wes

 

[PROSTAR190]

I am having the same problem. I recieved a reply on another thread that it might be the apps (tps). I have not tried this yet.

 

[Boost]

Had mine in the dealer today. They could find no codes and couldn't get it to duplicate the bucking. Went for a ride with the service mgr and it ran fine, no bucking. Drove home and so far the problem is gone.

 

[PROSTAR190]

My truck is getting worse by the day. Has anyone had any luck with a solution or herd of any suggestions?

 

[Tom W]

Mine did this last week. I had just gone over some very rough road and got the bucking and the check engine light came on. It seemed like a miss but I think it was the the fueling box (ottomind) cutting in and out. I disconnected and reconnected the map sensor connections, I think this is the same as the PE connections, and haven't had any problems since. I think the rough road loosened the connections.



Tom

 

[1BIG44]

Any ideas?

Tried a new EZ today, now I am back to making 30 psi. The missing is less noticable, but it is still occurring. Only with a good size load and pulling a slight hill. If I mash on down on the foot feed it clears right up.



Wes

 

[Runaway]

Think maybe the "Edge" guys may have to check the programming of the EZ if there is that many of us having the same symptom.

 

[KWIKKURT]

Originally posted by Runaway

Think maybe the "Edge" guys may have to check the programming of the EZ if there is that many of us having the same symptom.

I don't think it's the PE Boxes... My slight miss problem and cutout occurs with or without the box installed. I think it's the Map sensor or VP44 ... IMHO... ... .....

 

[Boost]

its baaack

The bucking went away for a couple days but its back now. Mine happens at only between 1/2 and 3/4 throttle. Fuel pressure is 13+ at cruising speed(below half throttle) and 7 at WOT. But when I am between 1/2 and 3/4 the engine is bucking and the fuel pressure changes rapidly from 10+/- to zero and back. Could this be a TPS problem somehow turning the lift pump on and off rapidly? Whatever it is causing it I believe it's fuel delivery related.

 

[KWIKKURT]

That does sound like it could be the TPS