Double check me here. Bad IP? - Hard hot start.

[WarWagon]

Did the 1993 DB2 IP not have the updated head and rotor in the IP? Is 134K a short life for the IP?

Since I bought the truck it has had a long crank but less than 40 seconds once and awhile after sitting a couple hours.

Yesterday it has to cool the starter between cranking sessions when heat soaked. It did this twice. Shut off and hard start again. Runs awhile then shut off restarts ok. Throttle floored or off idle makes a small difference in starting I think.

The truck would stall at one time till the idle was turned up. Not sure the idle is high enough now.

New injectors about 8K ago.

Lift pump is working and pressure good. Was not working when I got the truck with 124K on it. No air at the filter bled screw when checked.

So should I throw an IP at it or is there a couple other things I should try first? I assume I have the worn head and rotor hot start issue. Also found some metal shavings stuck to the shut off solenoid when I turned up the screw.

I have been using LSD instead of the ULSD as we have one of the few stations here that still sells it. Also gets proservice diesel clean thrown at it every 3rd tank(s) full or so.

 

[ak diesel driver]

try pouring water over the ip when heat soaked. If it starts easier than most likely ip

 

[buddy]

Shouldnt crank more than once a minute, 40 seconds straight will kill the starter pretty quick. Perhaps the compression is low, glowplugs arent working (if its below freezing) or the starter is not spinning fast enough (either weak starter or low battery CCA, can check to see how far voltage drops during crank, or perform load tests).

 

[Odlaw]

If you haven't turned the IP up yet, try it. Mine was having the same problem. Someone here (or at the place) suggested I turn the pump up - I think I've put over 20k miles on her without a single hard to start when hot problem.....plus, if you have big/open exhaust and intake you'll notice a pretty good power increase.

 

[buddy]

ahh yeah, its a hot start issue, that can often just be a battery or battery cable issue if its actually hot, wouldnt be glows of course. Batteries and cables when hot go up in resistance and cannot put as much current to the starter.

I know there was a time when mine would start lickedy split when cold, and then after driving a couple hours, it would have to crank about 5 seconds to fire up. I swapped out the batteries and it went away. They were supposedly maintenance free, so I couldnt get to the water to refill.

 

[WarWagon]

What is the cranking RPM for the 6.5? I will use a hand held tach to check that.

 

[ak diesel driver]

IIRC it's about 450

 

[Crankme69]

Is that something we can read with the gmdscan tech cranking rpm?

 

[ak diesel driver]

good ?

 

[Crankme69]

I find out tomorrow...new toy ya know lol

 

[6.2 turbo]

try pouring water over the ip when heat soaked. If it starts easier than most likely ip

x 2, your head and rotor is worn.

 

[Odlaw]

My understanding is that the head warps under the heat after shutting down and getting heat soaked.....usually take about 20-30 minutes after shutdown to cause this. Mine would always restart in the first 15-20 minutes. I can remember those days...in July, running through a store trying to get everything I needed and checked out to be back at my truck in that time frame so I didn't have to pour water over the IP. :mad2:

 

[buddy]

cranking RPM is 100-200rpm, if you disable to fuel by unplugging fuel shuttoff solenoid or removing the PMD connector, then you should be able to watch RPM in GMTDScan.

 

[WarWagon]

Looks like the fuel filter was totally black with 6400 miles on it. Maybe this was the issue. We will see.

 

[WarWagon]

Found the issue. Lift pump clanking away has been testing good with 7 PSI and good flow. Caught it after a hard hot start with low flow - I could pee faster - and less than 1 PSI.

Intermitant failure of the lift pump was the cause even when making noise it had no pressure at times. Bad valve in the pump I guess. New lift pump solved the hot start issues.

 

[buddy]

You sure it is the lift pump itself and not the way it gets powered? Have you performed the relay modification for the OPS? The OPS itself can fail intermitently.