Air in Fuel System -- How do you check?
I have a very tired 2.5 NA with low compression in cyl #1 @40%; all others @ 80%. I have not had time to change the motor back to the 300 tdi that's sitting in my garage. I am going to put that, a new tranny and a new xfr case in, but I won't have time to do that until the holidays. I still want to drive it 5 min to work down hill; then back 10 min up hill;-), but the long cranks are discouraging and I don't want to damage my new starter, or get stranded.
The motor takes a while to start -- about 20 seconds of cranking. Even when I stop momentarily and then try to start it again, it takes a while (engine at normal operating temp). Not 20 seconds, but about 10-15. I assumed it was because of the low compression, which may is probably a contributing factor, but it runs fairly well when warm.
I'm suspecting air is seeping into the lines when I cut the engine off. I replaced the fuel lines when I installed the motor, so I think they're leak free. Now I think it might be the lift pump (condition is suspect) is allowing air in the system. I could replace that cheaply enough ($27 on ebay), but is there some type of test I can conduct to confirm? Heard you could temporarily use clear tubing to see the diesel retreat back into the tank?