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Discussion Starter #1
Alright, so I am at a loss, and this issue is really starting to annoy me. When I brake coming down from 50+ MPH (in over drive) my truck idles down, but stutters and jumps. It seems to be happening more often as well.
I'm not sure how to describe this issue, but its similar to the "jump" in idle when going in to reverse that some people have. (My truck does this some times as well)
I first noticed this issue starting after I replaced the injectors. When I test drove it, it did this "jump" when I accelerated up to about 50 (truck goes into OD at about 46 on my spedo) and when I applied the brake, it did it.

My truck is mostly stock, I've got an after market carter lift pump for Leroy Diesel, along with his LP relay kit. New glow plugs, and Injectors, and a remote mounted PMD in the bumper. Otherwise its stock to my knowledge.

Below is a link to a video of what I'm describing. Any help/insight would be greatly appreciated as I'm really getting tired of my truck doing this.

Also when my truck does this, sometimes i notice some grayish-white smoke coming out the exhaust. Its usually pretty hard to tell, and It only does it during this surging.
 

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1995 GMC Suburban
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17,789 Posts
What model year?
Which injectors do you used to replace? Who do you get the injectors from?
 

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Welcome to DieselPlace
Do you have a fuel pressure gauge to monitor pressure?
With the engine running, open the T valve for approximately 30 seconds and let fuel drain into a container.
During that time, if the engine dies and/or you see no fuel flowing from the line your lift pump is too weak to support the fuel system.
Open your fuel cap. Do you hear a large "Whoosh" sound? If so then you have a restriction and need to modify your fuel cap for better venting.

Install a piece of clear line on the return side of the Injection pump to help look for any air in fuel, as shown here: Question: - 1999 GMC Bluebird 6.5L TD - PMD &amp...

Go through all of your grounds: Grounds-Grounds-Grounds The importance of good grounds.....
 

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Discussion Starter #5
Alright, I'll have to try the T-valve thing this weekend, I got caught up doing some other things last weekend. I did end up replacing the fuel hose with a clear one, and didn't see any air bubbles in the line. However, when I primed the system (key on LP running) I noticed the fuel didn't really fill up the line. I saw fuel go up slowly and then just stop when it got to the peak. When I ran the pump longer there was no change. Should there be fuel going all the way through the line when the LP is running? Once the truck was running fuel was flowing just fine.

As for the fuel pressure gauge, I do not have one, and have not used one.
I have not noticed any pressure change with the fuel cap.

I suspect my LP may be the problem. Other than the Carter pump being much louder than the old stock one that was in the truck when I got it, I really haven't notice a difference.
 
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