I think Wes has shown that it does help. I don’t remember the final outcome though.
Building a better db2
- Thread starter Thewespaul
- Start date
I’ve got a 10 row fuel cooler, I haven’t gotten a fuel temp gauge setup but that will be apart of the 38 gallon single tank conversion whenever I get a chance to work on it. When I installed it I noticed the timing seemed to change less with engine temp.
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nelstomlinson
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Wes, what manual is that you attached pictures of?
ifrythings posted those pictures, looks like a stanadyne publishing.
ifrythings
Full Access Member
I got these manuals from the local international dealer that closed down 5 years ago.
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IDIBRONCO
IDIBRONCO
Man, is there anything that you don't have on that truck? I'll bet you carry a spark plug around in the glove box just so you have one of those too.
To be fair, all you need to copy my current setup is:
Junkyard na 7.3
Studs
Stock idit turbo kit
intercooler setup
Original used injectors cleaned and pop tested
CDD db2
GSL392 fuel pump or equivalent
Holley 12-803BP regulator
That’s it for performance adding parts, having a clutch and gauges are nice too, but overall it’s a simple setup to copy, if you get a complete used idit you’re gonna get your best bang for buck, you will get the turbo kit, better rods, turbo injectors and a 92+ pump housing so you will have torque screw adjustments.
Junkyard na 7.3
Studs
Stock idit turbo kit
intercooler setup
Original used injectors cleaned and pop tested
CDD db2
GSL392 fuel pump or equivalent
Holley 12-803BP regulator
That’s it for performance adding parts, having a clutch and gauges are nice too, but overall it’s a simple setup to copy, if you get a complete used idit you’re gonna get your best bang for buck, you will get the turbo kit, better rods, turbo injectors and a 92+ pump housing so you will have torque screw adjustments.
1-I guess if I had a test stand and planned to put the IP on my truck I would try some runs with the truck injectors (on the stand). Unless I was paying for test time. Comment only because of noted stand/truck difference.
2-Are delivery valves just check valves and don't need balancing?
Is post POP line pressure "set" by injector and POP pressure curves?
If line pressure leaks past pintle before/after POP which increases with IP/injector temp , then cranking below some critical speed (different everyone based on above) will not attain POP, no injection, no smoke. Not just retarded, nothing.
Is shutdown due to blocked returns a safety feature, somehow, or just consequence of no return springs for dual plungers? Anyone try adding return springs?
Can Leaking return lines drain injection lines meaning long cranking?
Air before IP causes stall when it reaches where in the IP, transfer pump, dual plungers? After stall, governor housing should still be full of fuel like after normal run/shutdown. Transfer pump with air. Air anywhere else in IP? Above recap, I hope, mainly to consolidate my thinking @ IP operation
2-Are delivery valves just check valves and don't need balancing?
Is post POP line pressure "set" by injector and POP pressure curves?
If line pressure leaks past pintle before/after POP which increases with IP/injector temp , then cranking below some critical speed (different everyone based on above) will not attain POP, no injection, no smoke. Not just retarded, nothing.
Is shutdown due to blocked returns a safety feature, somehow, or just consequence of no return springs for dual plungers? Anyone try adding return springs?
Can Leaking return lines drain injection lines meaning long cranking?
Air before IP causes stall when it reaches where in the IP, transfer pump, dual plungers? After stall, governor housing should still be full of fuel like after normal run/shutdown. Transfer pump with air. Air anywhere else in IP? Above recap, I hope, mainly to consolidate my thinking @ IP operation
You can’t run a regular injector on a test bench, you have an accumulator to account for and a specification for the orfice plate and pop pressure to calibrate the pump. The fuel system on a test bench is very different from what’s in a truck.
There’s only one delivery valve.
Line pressure is controlled by delivery valve and injector pressure settings.
If you have a leaking pintle yes you will have leak down problems.
Fuel is shut off by the metering valve being closed when you turn the key, if the return is blocked the pump shuts off because it reaches equilibrium in internal pressure and displaces nothing.
I don’t see a reason why our plungers would need springs when they are always under pressure with the engine running.
Air intrusion anywhere will cause hard starts.
You should get a stanadyne manual and read up on these pumps operations, you would answer a lot of your own answers doing some research.
There’s only one delivery valve.
Line pressure is controlled by delivery valve and injector pressure settings.
If you have a leaking pintle yes you will have leak down problems.
Fuel is shut off by the metering valve being closed when you turn the key, if the return is blocked the pump shuts off because it reaches equilibrium in internal pressure and displaces nothing.
I don’t see a reason why our plungers would need springs when they are always under pressure with the engine running.
Air intrusion anywhere will cause hard starts.
You should get a stanadyne manual and read up on these pumps operations, you would answer a lot of your own answers doing some research.
Test bench has only one delivery valve? Per injection line? In addition to IP? Piping diagram of test bench would be elucidating.
As to leaking pintle, I though they all leak after some use, it's just a matter of how much. At some point it affects start rpm, no?
Blocked return displaces no fuel because pumping plungers have no return springs, someone said. Would blocking only 1 injector return shut down only that cylinder? I guess bigger return lines safer than return springs for restricted return possibility.
Understand air intrusion causes hard starts. Question is, air to IP gets how far before a stall?
If I could find the manuals at a reasonable price I would be reading them right now.
As to leaking pintle, I though they all leak after some use, it's just a matter of how much. At some point it affects start rpm, no?
Blocked return displaces no fuel because pumping plungers have no return springs, someone said. Would blocking only 1 injector return shut down only that cylinder? I guess bigger return lines safer than return springs for restricted return possibility.
Understand air intrusion causes hard starts. Question is, air to IP gets how far before a stall?
If I could find the manuals at a reasonable price I would be reading them right now.
The IP has only one delivery valve.
Good injectors shouldn’t leak when tested
Only blocking the main IP return will cause it to shut off, not injector returns.
Good injectors shouldn’t leak when tested
Only blocking the main IP return will cause it to shut off, not injector returns.
Thank you and is this manual useful for just short of overhaul use?
DB 2AJ 3AJ 4AJ 6AJ FUEL INJECTION PUMP no/for D-166, D-188 ENGINES
And warmer fuel on truck vs test stand reduces flow because it increases leakage where, only in IP, or also injector return flow?
DB 2AJ 3AJ 4AJ 6AJ FUEL INJECTION PUMP no/for D-166, D-188 ENGINES
And warmer fuel on truck vs test stand reduces flow because it increases leakage where, only in IP, or also injector return flow?
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nelstomlinson
Full Access Member
Search around, there are copies of the Stanadyne manuals on line.
nelstomlinson
Full Access Member
I had thought the warmer fuel issue is that warmer fuel is less dense. I hadn't thought about the lowered viscosity, but that's probably an issue too.
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