Engine/Transmission (1994 - 1998) Balancing fuel output from pump and injectors.

[RonA]

My truck has been running rough since the p7100 conversion. Is there a way to balance the output of the pump and injectors to make sure that an equal amount of fuel is being delivered to each cylinder? If so, who does this.

Ron

 

[DPinkston]

This is the way I understand it. At the base of each delivery valve there are 2 nuts holding down the base. Pump shops balance the delivery between injectors by loosening these nuts and turning the base. The pump must be on a stand to do this, can't be done on the engine. Probably not what you wanted to hear.

Danny

 

[RonA]

I figured there was a way to balance it. But I am looking for a place that can do the pump and injectors. No intention of doing it myself.

 

[Jim Fulmer]

Ron, if the injectors all pop about the same then the pump should go to a good stand for balancing, heck even my truck idles very well.



Jim

 

[RonA]

After trying several sets of injectors I figure it has to be the pump. The new lines helped a bit. I want to remove it and send it to be checked out. I could really hear it on the load dyno. almost sounds like its running on 5 instead of 6. After talking to a couple of people today I am going to replace the delivery valves. The symptoms seem correct. 1 guy said pump stand may not show a DV problem because they don't run warm enough on the stand. Found some 181s in Sacramento. Will be a cheap easy fix if that's all it is.

 

[Reno Guy]

You might want to check the size of your fuel lines. I just had a major overhaul on my truck. When I went from 160 injectors to 215's, the fuel lines were restricting flow and causing an excess suction vacuum. The dealership told me the changed the fuel line size to 3/8" after or mid 1994.



The shop mechanic disconnected my fuel lines and ran a 3/8" line into a jerry can. The idle smoothed right out. Until then I thought it was going to rock itself off the hoist!!



Just my $. 02



Scott

 

[Reno Guy]

By the way, have any of you heard of the fuel lines being too restrictive when upgrading injectors / pumps or is my mechanic blowing sunshine??



Don't mean to hijack your post.



Scott