lly long cranking times
- Thread starter jpatt
- Start date
You're just wasting your time if you don't go right to looking at rail pressure and verifying it if the system is primed to the Cp3 and its a hard start especially when hot its your injectors bypassing too much fuel to make the 14-1500 the ecm wants to see to enable injection. not what you want to hear but damn good chance that's it. duramax's will start in the single digits with no working glow plugs. might fire and die but they will start
you might be making full power but the rail pressure could still be down 5-6K under wide open throttle. seen this many times.
I can assure you that injectors with high return rates will cause low rail issues... My truck would only make 18k with 2 bad. If they all come back clean and the balance rates are in spec. then you will need to do a return test on the cp3 pump.
http://www.duramaxdiesels.com/forum/showthread.php?t=41181
http://www.duramaxdiesels.com/forum/showthread.php?t=41181
It has been checked. Cp3 is good, rail pressure is low. They told me injectors were bad
CP3 can cause the exact same symptom if it returns too much fuel just like the injectors. .
Ok. I'm clueless man about diesels. Going to look at balance rates tomorrow. I know that's not ideal but maybe 1 or 2 will show like -7 or something. Then if they do then I'll do a return test on those ones. It's a local diesel shop where I work who is checking the balance rates for me. I'll talk to them and have them explain some stuff to me
But it won't have shit for power when it goes bad. seen that before. usually starts fine but no balls.
bal rates can be totally fine but checking for a couple bad ones at your miles
it just needs a full set.
If it needs injectors and even a cp3 at that "broken in" mileage its not the end of the world. Whats your location and can you do it yourself?
Picked truck up.
Summary is...
When hot- cranking pressure will ramp up slow to 1500 and fire.
When cold- cranking pressure will ramp up slightly faster and fire. Injector balance rates were all within +/-2
Test drove truck and fuel Temps would climb to 160 within a few miles. Ramp pressure at idle would only build 18.5k when hot when commanding 23k. Bring rpm up slightly and pressure will increase.
Injectors returning to much fuel to build pressure at slow pump speed.
Talked to him for a bit and he went WOT with it and it holds pressure for the whole time. Says truck is great and is well worth putting injectors in. But 3840.00 total cost is the issue. Asked about just doing a few and as he explained that I'm better off doing them all at once. Looks like I'm saving money for a while
Summary is...
When hot- cranking pressure will ramp up slow to 1500 and fire.
When cold- cranking pressure will ramp up slightly faster and fire. Injector balance rates were all within +/-2
Test drove truck and fuel Temps would climb to 160 within a few miles. Ramp pressure at idle would only build 18.5k when hot when commanding 23k. Bring rpm up slightly and pressure will increase.
Injectors returning to much fuel to build pressure at slow pump speed.
Talked to him for a bit and he went WOT with it and it holds pressure for the whole time. Says truck is great and is well worth putting injectors in. But 3840.00 total cost is the issue. Asked about just doing a few and as he explained that I'm better off doing them all at once. Looks like I'm saving money for a while
It's a fair price either way for diagnosis, parts, and labor. You'll spend a lot more finding a different truck to haul your trailer.
Negative, I had a truck about a year ago with the same symptoms as the op. New cp3 and a double check of the injector return rates and off they went.