Any recommendations for a diesel specific fuel injection test kit? Most commonly 5.9, 6.7 and 8.3 cummins?
Thanks,
Cory
Sry for the hijack.....
You have to specify which pump, since they have vastly different characteristics. I don't do common rail, but IIRC from a chrysler training I did, they mention 23,000psi high side.
On the other hand, the 5.9 was around for almost 20 years and had atleast 3 different types of injection pumps. The 8.3 shared some of them.
If you really must know high side pressures, it is probably easier to use the OTC vibration clmap that clips on the individual high side lines.
If you are doing low side transfer or return line restriction test, you can make something yourself, so long as you know specified pressures for your pumps.
Don't forget a vacuum gauge BEFORE the transfer pump. Often overlooked. 0 cranking vacuum could indicate out of fuel, hole in fuel line/pickup tube, or bad pump. Excess vacuum can indicate a pinched line or plugged pickup. 3-4" is often considered acceptable.
Often times you can tap into a bleeder port on top of the filter housing, depending on make/model of the engines chassis. Port's are often 1/8NPT standard, so it's easy to cobble something up. Diesel doesn't pose much speciial risk to most hose/fittings/gauges either.
Buy what you actually need, for a modern car that usually means if you can hear the fuel pump running, its working.
I'm thinking for myself to buy a few of the $20 gauges like Summit sells and mounting them permanently on my fuel rails. No need to store it, find it, or hook it up, 5 seconds to look at it and see if the pressures look ok, which 99% is all you need to rule out half the trouble shooting.
That is very often not true. Ok pump whirs. Doesn't tell me that it is pushing enough fuel or not bleeding down. Check valve bad, flex tube bad, worn commutators.
That isn't even covering the next 25ft of fuel system from tank to injectors back to tank if it has a return system.
A permanent rail mounted gauge may have some use, but in order to use it to it's fullest capacity, you need 2 people. One person has to ride around on top of the engine while the other takes it for a drive, or atleast power brakes it. As you can imagine, much less safe and convenient than using more appropriate tools that better gauge
volume. About the only thing you can do is a return system dead head or static test, far from conclusive.
