Long Crank Times & Sometimes No Starts

[CoastyAV8R]

I agree that on high mileage trucks that may be the case as some guys will get over 200,000 miles out of a set of injectors and you know they don't have much more life left in them. For someone like me who has 80,000 miles if I have 2 or 3 bad injectors that don't meet the specs and the rest are fine, I may be tossing an injector that has many miles left in it for no reason other than I don't want to take the time to see what the injector flow test results are. I think if you take a baseline injector return flow measurement with all 6 cylinders running and then you cap each one off and take the measurement, it wouldn't be hard to figure out the return rate of each injector with a little math.

The variable for me is the fact that my truck most likely has a higher return rate when it's hot than when it's cold since it doesn't like to start when it's warm so I would have to try to get the test done within an hour or 2 before the engine cools all the way back down. I'm gonna atleast give it a shot and see what happens.

I know TWest has tons of experience with the trucks and maybe I'm just a jackass for even trying it but what the heck. I'll be buying my injectors from him since you can beat his price and customer service, I hope to just be buying 1 injector but it damn well could be all 6...

 

[sag2]

There is no reason to throw away all the injectors when only one or two are bad, especially at low <120,000 miles. The only exception is when you know you had fuel contamination, then it really should get the complete fuel system.
The fuel return test is a great way to find the bad injector(s). It is not hard to do and is best done with the engine hot. If it's starting to cool down, let it idle for a few minutes to warm it back up. The pump return from the 9012 will need to be in a large container, or dumped back to the tank often to keep it from overflowing. Go to Wal-Mart and buy the plastic measuring cups for the injector and pump return for less than $6 total. You need at least 2 quart/liter for the 9012 (pump return) and hopefully less than 1/2 quart/liter for the injector return (quick disconnect at the bottom of the filter). Once you have the pump return test results recorded once, put the hose in a five gallon can because capping off the injector will not change the return from the 9012.
A perfect injector will return about 10ml each, or 60ml total in 30 seconds. Keep this volume in mind when purchasing the different size containers. The scan tool has an actuator that sets the RPM to 1200 and the rail pressure to 20,000 for 30 seconds for you. If you don't have assess to one, run the test at idle and pull the FCA connector for the 30 seconds. Don't let it run any longer than necessary with the FCA disconnected, and only at idle. You risk ruining the pop off valve if you exceed max pressure.
See note below from TSB 14-003-06 REV A.


NOTE: Maximum leakage allowable for all injectors combined is 160 mL (5. 4 fl. oz. ):
taken when engine coolant temperature is greater than 82°C (180°F), engine
speed is equal to 1,200 RPM's, and fuel rail pressure is equal to 1400 bar
(20,305 psi. ).
NOTE: It is critical that all HPC nuts are tightened to the correct torque. Refer to the
detailed tightening information available in TechCONNECT under: Service
Info tab > 14 - Fuel System > Fuel Injection > Fuel Injector > Installation.
Retest when all HPC nuts are properly torqued.
14-003-06 REV. A -4-
NOTE: Any injector contributing more than 40 mL (1. 4 fl. oz. ) is excessive (Example:
If total injector leakage is 200mL (6. 7 fl. oz. ) and blocking cylinder #1 reduces
the leakage to 160 mL (5. 4 fl. oz. ), cylinder #1 has excessive leakage).

 

[TCDiesel]

Sag2. . That works. . But the real Question who is going to Pay the additional cost of Shipping ,Down time,R/R. . ? What about if the same issue Persist even after you believe You have settle on 1 or 2?. . Injectors will live for 1000s of hrs 100 thousand of miles, so 1 or 2 are down its easy to say I'M saving $$$. . Do you call the seller on the Products YOU install? You get Paid as long as You follow the shingles rules regardless of the hassle to the Owner. . You cannot Purchase the time. Generally the rule and Years of experience (30 Years) and selling injection Products ,save yourself the turmoil and do it right once. Just the thought the of the rest failing. . What Price tag can you place on that. Heck I'm not on this forum to Make More MONEY,I have More then I can spend... ... ... I am in this Profession to provide a service and hope to make a modest profit.

 

[CoastyAV8R]

Swithrow, what's your status on this? I'm doing the last troubleshooting steps this weekend on mine and I was curious if you'd made any headway on yours.

 

[SWithrow]

I still have the starting problem#@$%!, I am getting ready to order a set of injectors (I will have a almost new fuel system:-laf)

 

[MechanicMike]

We had a similar problem on a duramax at work. Would start and run fine cold. Once up to operating temp, it would not restart unless we hit it with either or let it cool. We wound up measuring the fuel return rate. On the GMs they measure each injector individually using a kit from GM. Found our leaky injector. Wound up changing the whole bank while we were in there. That was 2 years ago. Haven't had a problem since.



Mike

 

[SWithrow]

Well, a new set of injectors (a lot of#@$%!) and it seems starts and runs fine. Fires up first time and runs smooth. Maybe I can get 160k out of this set. Thanks for all who helped me with this problem. I have learned a bunch about the fuel system (maybe more than I hoped to) and I would like to also thank TWest for the trouble shooting help and the loaner test parts, your knowledge has been invaluable. <O</O

 

[CoastyAV8R]

What problems did you encounter with injector install

I've been following your thread and I'm glad to hear you get it taken care of. I'm getting ready to change my injectors on Friday and I was curious what problems you encountered during your installation? I'm hoping your experience can save me from having to go through the same grief and heartache.



Thanks,

Patrick

 

[SWithrow]

The only real problem is the #6 injector for me, I did not have the injector tool so with limited space to work on and no tool I busted a knuckle or two. Have patients and don't hurry. The injectors will pop out with a slight pull while prying up. The tubes will pop out with a little pull again have patients. This is the first time for me and I started at 5pm Tuesday worked until 2am, started back up today at 3:30pm and truck was running at 6pm. Not bad for a old Air Force mechanic.

 

[CoastyAV8R]

I changed #3 and #4 today as those were the ones that were leaking out of limits when I did the injector return test on the truck last week. Now the truck starts so damn fast now, I have to remember to let go of the key before I grind the starter, what a difference. It took 2 hours to do which was a lot faster than I thought. I know if I had to do #6 it would have been a much more difficult task as that puppy is damn near in the glove box...

 

[SWithrow]

Follow-up one week

I was out on business this week and the wife drove the truck into Maryland (a 400 mile trip plus a weeks worth of back and forth to work) and all is great!!! The truck fires up the first shot every time. She used about 7/8 of a tank. I hand calculated and the truck is at 20mpg with her driving and the BullyDog set to Extreme. (this is the first tank since the new injectors) I am impressed :-laf with the stage1 CP3 along with new stock injectors.

 

[SWithrow]

Murphy's Law

The engine is running GREAT, took a trip to Pittsburgh from Virginia and the truck averaged 18. 8-19 mpg. After fixing my truck the wife's Intrepid tanked, had to replace the water pump and alternator. Got that fixed and the front band on the pickup cracked on the lip of the band. Currently I'm in the process of pulling the 48RE and replaceing it with a heavy duty band, strut and wedge.