12 valve dies while driving

B

bowhunter87

New member
Ok guys I just put the motor back in my truck after resealing it and doing a few mods. Now when I drive it I only make it about 3 miles and it shuts down. It only happens when I let out of the throttle to coast, then I put my foot back in it and its dead. Won't die when its just sitting there or being revved in neutral. A few times it even revved on its own before dying like a runaway condition. Its a 94 5 speed. I recently put in pacbrake 3000 gov springs, ground my fuel plate, adjusted the pre boost fuel screw in 3/4 turn and adjusted the star wheel forward. I checked the shutoff solenoid and its staying up. Thanks for any help
 
I agree on idle speed first, is it worse with the A/C on? Is there any smell of fuel anywhere?
 
Idles at 800 rpm, no fuel smell or leaks that I can see. A/c isn't hooked up right now. Seems like its in the injection pump but it seems odd that it never happened before
 
Also when it dies it takes some throttle and quite a bit of cranking to start it, any other time it starts fine. When it dies I can hear a ticking coming from what seems like the injection pump
 
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Springs were tightened to .045 to the top of the nut, its strange that it won't do it just sitting there in neutral. It revs fine and idles smoothly. Drives great until it suddenly shuts down
 
When I bought my truck it was doing this exact same thing. It ended up being the rack sticking in the pump. Sent it off to Seth for a rebuild and it was good to go
 
Definately hard guage the fuel pressure. Find out if it's low.

Then move up the board to governor and then rack.
 
bowhunter87 said:
Any tips on installing a fuel gauge that I can monitor while driving?
Click to expand...

There are ones out there that you install just like any other gauges in the cabin. Make sure you get a snubber to dampen out the pressure spikes from the lift pump.
 
If you hear a ticking and it dies I'll bet money the b&p are worn and hanging up in the pump once it warms up. 160 and 175 pumps are notorious for it.
 
It seems strange to me that the plungers would have a problem now when it was running fine when I pulled the motor , I was leaning toward a gov spring issue but I was extremely careful installing them. It sounds like a pump issue is likely Though
 
If it is the pump am I better off getting it rebuilt or just buying one of the bd diesel pumps from thoroughbred for $1250, not sure what the cost of a rebuild is
 
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