Cummins 4BT & Diesel Conversions Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter #1
So I have been getting the time to work on my 4bt swap into my f150. I am to the point to we’re I want to start it but my motor will not start. I bought the engine maybe 5 years ago, it ran when I bought it and had been sitting in my garage or in the Engine bay since.

I replaced the mechanical fuel pump on the side of block because I wasn’t able to get fuel to injectors. Now with it replaced I cracked the injectors one at a time and cranked the engine supplying all the injectors but won’t start. The engine cranks and smokes but will not start and I have no idea. I am running duel batteries.

If anyone can give me advice to my problem that would be greatly appreciated. THANKS
 

·
Registered
Joined
·
1,414 Posts
Do you have +12 Volts to the fuel shutoff solenoid on the injection pump?

VE pump or P pump? - The details of troubleshooting vary.
 

·
Registered
Joined
·
21 Posts
Discussion Starter #3
Yes I have the three wires hooked up and working properly with the key. It is a p-pump bone stock.
 

·
Registered
Joined
·
46 Posts
3.9,

Last year I landed a v504 cummins (Yea I know its a 8.3L v8, but it is still pretty cool)... I'll bet the motor hadn't been started in at least 8 years. It took me two battery charges (the starter motor is an MT42) before the motor started to even puff smoke. I don't know how long you leaned on the starter, but it may be that you still have some air in the lines/injectors that needs to be purged. My motor ran a bit rough at first, but as more air was purged out it evened out and ran nice.

Cj
 

·
Registered
Joined
·
10,922 Posts
When you turn it over with an injector cracked, what kind of spray do you see? Is it sort of dribbling out or hitting the top of the hood? That stuff should have extreme pressure and need to take care to keep hands and body parts clear. Don't want diesel injected into your blood stream. Not nice. Have the injectors been tested for pop pressure? You could have a weak overflow valve in the P7100 which will vent most of your fuel back to the tank. Do you have a fuel pressure gauge on the engine? Should have pressure in the 25-30 PSI range for a P pump. The smoke is at least a sign some fuel is getting in the engine. The issue could just be you haven't gotten all the air out. With your wiring, I assume you have a relay in the circuit for the pump solenoid. Those don't take much to keep the circuit open, but lots of juice needed to initially open it. Also, engines that sit for long periods can have parts gummed up in the injection pump. Is the starter spinning the engine fast or slow? Do you have large gauge positive and negative cables? Just a few ideas here to think on.
 

·
Registered
Joined
·
21 Posts
Discussion Starter #6
Yes I have large power cables. Got a set from a 7.3 same body style as mine, along with setting up dual batteries. When I cracked the injectors it would spray the hood with fuel, I just replaced the overflow valve with the tok tech one. I am not chasing down the timing.

My engine plate has an advance timing of 11.5 degrees, I understand the process in doing so. I have the engine at tdc along with the p-pump at tdc. I’ve watched a lot of videos and read forms but I can not understand the advancing part on the crank gear. I know you have to pull the crank pin and turn engine and reinstall pump gear with dry clean shaft with avoid slipping. My confusion that I am asking advice for is the degrees or turn of the crank gear for 11.5 degrees. If anyone has any information on this it would help in starting my engine. Thanks
 

·
Registered
Joined
·
40 Posts
If i read you correctly your trying to determine where 11 degrees is on your crank. You can use a degree wheel or alternately mark flywheel position at tdc, count teeth on flywheel, divide into 360 which gives you degrees per tooth.with engine at tdc back past tdc the number of teeth equal to advance you require.
 

·
Registered
Joined
·
40 Posts
Also be sure to go back past 11.5 and bring it back in direction in direction of rtation to allow for clearance in bearing and gears
 

·
Registered
Joined
·
21 Posts
Discussion Starter #9
So update on my truck. I went ahead Replaced the overflow check valve coming from the fuel return. I also re-timed the injectors pump. I am not sure which fixed it but I got it running and idling. Thanks everyone for the help
 
1 - 9 of 9 Posts
Top