Slow to Start

[williambryan]

Please move this to a new Thread where it needs to be.
I have a 2003 Duramax with 160000 miles, original injectors and all filters including the fuel filter has been changed within 2000 miles. It does not smoke much, runs good (other than takes much more cranking to start), no fuel in the oil etc. The wait to start light goes out in 5 to 10 seconds. Twice I had to spray some starter fluid in the air cleaner box to start it in the past month. I am the original owner and take very good care of this truck. Anyone have any input on where to go from here will be appreciated.
Thanks,
williambryan

 

[Kat]

Moved here.

Check the fuel filter housing for a a crack or a leak.

But, I wouldn't use starter fluid/ether. You are taking a chance to blow up your engine.

 

[williambryan]

Fuel filter housing not cracked or leaking.

 

[McRat]

I've only had LLY/LBZ/LMM engines, but none had 5-10 second glowplug lights.

Fuel is "sucked in" to the top front of the engine. If there is a crack in the filter hsg, it might not leak, but it might let in air.

When you pump the filter, does it start quicker?

 

[1chevy02]

Can be high return rates on injectors.

 

[blk smoke lb7]

fprv maybe bad letting fuel return to the tank instead of presurizing the injectors and what ever you do dont spary starter fluid in the intake even the grid heater can ignite the starting fluid in the intake horn our you could destroy the motor find someone with a v2 or a gm tech 2 that can take some readings and see whats going on

 

[williambryan]

In most starts it cranks for 4 to 5 seconds after the glow light goes out. This in longer starts than I experienced in the past where it would start in 2 to 3 seconds, however sometimes it takes a couple cranks to get it started. I tried pumbing the filter pump this morning and it started in 4 seconds......I may be complaining over nothing however twice it took starter fluid to start it.............I will be more careful if I have to go to that extreme again but If I am stranded thats the choice I have to make. With 160000 miles on the original injectors I am conserned if that would be the problem. I guess I am looking for justification to change them since I can take my time and do them myself. I subscribe to Alldata and although I am not a Diesel Mechanic, I am a old school car mechanic and retired aircraft mechanic that goes strickly by the manual. I can't afford an new truck and want to keep the maintenance up on this truck before something goes out on the road and I am at the mercy of a repair shop.

 

[williambryan]

I've only had LLY/LBZ/LMM engines, but none had 5-10 second glowplug lights.

Fuel is "sucked in" to the top front of the engine. If there is a crack in the filter hsg, it might not leak, but it might let in air.

When you pump the filter, does it start quicker?

How many seconds if normal.............I pumped the filter and it started in about 4 seconds.........it used to start with less cranking and reciently sometimes it takes two cranks to start it. I maybe just "picky" and just want to do some preventative maintenance before something goes wrong on the road. 4 friends of mine have had to change their injectors with less than 130000 miles........I have 160000. I keep getting the question "have you had to changed the injectors yet? " I don't get much smoke just some soot on the lower fender and no fuel in the oil.

Don't see any cracks in the filter housing ............is this a common problem?

 

[McRat]

Several people have reported "hard start" issues with LB7 filter hsgs have air leaks.

Check your glowplugs with an ohmmeter. Fast and easy. You should show nearly 0 ohms. Open circuit means replace that glowplug. Unplug the main power for the glowplug module and see if startup changes. If it gets harder to start, most likely fuel starvation.

 

[ripmf666]

Is the filter head primer hard when you always try it or is it very easy. If its easy could use new seals in the housing to keep from sucking air. As Pat said check the glow plugs or even the relay and fuse for them. You might say you will do.what you have to using starting fluid but are you ready to replace the motor. It has and will explode in the bore before cranking over from the glow plugs and has distroyed pistons and heads and blocks.

 

[Stingpuller]

Crank time

You need to put a scanner of some sorts and check the crank rpm(need 150) and see the act. rail pressure(needs 1400). I'll bet your injectors are returning to much fuel. Also check your return rate 12ml with 15 second crank time for one side(3 ml each). I have had a rash of injectors at the shop. Also does it seem to start faster when it's cold and harder starting when it's hot? Jeff

 

[williambryan]

several people have reported "hard start" issues with lb7 filter hsgs have air leaks.

Check your glowplugs with an ohmmeter. Fast and easy. You should show nearly 0 ohms. Open circuit means replace that glowplug. Unplug the main power for the glowplug module and see if startup changes. If it gets harder to start, most likely fuel starvation.

thanks i will look into it

 

[williambryan]

You need to put a scanner of some sorts and check the crank rpm(need 150) and see the act. rail pressure(needs 1400). I'll bet your injectors are returning to much fuel. Also check your return rate 12ml with 15 second crank time for one side(3 ml each). I have had a rash of injectors at the shop. Also does it seem to start faster when it's cold and harder starting when it's hot? Jeff

Thanks I don't have a scanner yet or will buy one or pay to have it done. Your advise is very helpful and gives me a start to work with. The filter pump does get hard when pumping. It is usually harder to start when it sets without starting for a day or so.

 

[williambryan]

Is the filter head primer hard when you always try it or is it very easy. If its easy could use new seals in the housing to keep from sucking air. As Pat said check the glow plugs or even the relay and fuse for them. You might say you will do.what you have to using starting fluid but are you ready to replace the motor. It has and will explode in the bore before cranking over from the glow plugs and has distroyed pistons and heads and blocks.

the filter pump does get hard

 

[williambryan]

I've only had LLY/LBZ/LMM engines, but none had 5-10 second glowplug lights.

Fuel is "sucked in" to the top front of the engine. If there is a crack in the filter hsg, it might not leak, but it might let in air.

When you pump the filter, does it start quicker?

starts the same......pump does get hard