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Hard Start after some maintenance

revyd

revyd

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This has got me shaking my head and I hope someone else may have an idea.

During the summer, I installed a Powermaster starter. Since then, the truck has been starting great until a couple of weeks ago.
The truck will start, but it requires a longer crank than before. I changed the fuel filter, but no change. Then I decided to change the OPS to see if that could be contributing. Now it's maybe more consistent with the hard start. When I changed the OPS, I removed the glow plug relay to access the sensor, and I noticed that the connector is missing part of its case, but all the blades are connected.
The glow plugs are only a few months old. The plug harness was replaced at the same time. The glow plug light comes on in the cab as it should.
I thought it might be a fuel/air issue, but I'm not seeing any air in my clear line.

I don't know where to go from here except to this group of experts.
 
the longer time cranking, is it a consistent crank not trying to fire off until it just starts up or is it trying to fire up?

I assume batteries are hot and it's still cranking like when you installed the PM starter. is there a service engine light on after it is running or any smoke or stumbling during crank or after it fires up?
 
With the longer crank it is trying to fire up.
Batteries are good and yes it's cranking like when I installed the PM.
No service engine light. The glow plug cycle seems to be running as normal.
White smoke on start but a little bit more than before.
It does stumble a little when cranking and of course it's not consistent. Sometimes (not regularly) it starts like it normally would have.
 
Injectors could be the issue, but I doubt that would just suddenly appear, that would be a slow over time get worse situation. I would start off by checking fuel pressure at the IP inlet post filter. easiest and most simplest way would be to pick up a tester from the local harbor freight and plumb in where the rubber hose goes in to the IP.

I can't remember if one of the T drain valves is post fuel filter or not. the LP might be working but not pushing fuel like it should. are you running the stock style LP?
 
depending on the age and mileage on the GP's and injectors, I would also try to rule them out but also plan to replace very soon.

GP's use only AC Delco. the OEM was the 9g's but we all are recommending to use the 60g's due to them not expanding in the head causing a massive "oh shit" moment they do take longer to heat up and you may need to install an override button for colder starts. that is a simple modification for your 95. simply tap into the yellow wire going to the GP relay and run it to a push button in the cab. then connect the other end of the button to a keyed fused positive. 5 amps is plenty, the yellow wire is the trigger wire coming from the PCM to activate the GP solenoid.

while your at it, you might as well do the relay mod for the LP too. it will save on your OPS and you can add a wire from the GP solenoid to the 5th pin of the relay which will activate the LP while the GP's are heating. this will help prime the fuel system. 96+ already has this feature built into the PCM to prime the pump. 95 and earlier doesn't.
 
dbrannon79 said:
Injectors could be the issue, but I doubt that would just suddenly appear, that would be a slow over time get worse situation. I would start off by checking fuel pressure at the IP inlet post filter. easiest and most simplest way would be to pick up a tester from the local harbor freight and plumb in where the rubber hose goes in to the IP.

I can't remember if one of the T drain valves is post fuel filter or not. the LP might be working but not pushing fuel like it should. are you running the stock style LP?
Click to expand...
I was planning on ordering a fuel pressure gauge sometime so I ordered one today.
I am running a stock style LP. It’s for a 93. It’s less than a year old.
 
dbrannon79 said:
depending on the age and mileage on the GP's and injectors, I would also try to rule them out but also plan to replace very soon.

GP's use only AC Delco. the OEM was the 9g's but we all are recommending to use the 60g's due to them not expanding in the head causing a massive "oh shit" moment they do take longer to heat up and you may need to install an override button for colder starts. that is a simple modification for your 95. simply tap into the yellow wire going to the GP relay and run it to a push button in the cab. then connect the other end of the button to a keyed fused positive. 5 amps is plenty, the yellow wire is the trigger wire coming from the PCM to activate the GP solenoid.

while your at it, you might as well do the relay mod for the LP too. it will save on your OPS and you can add a wire from the GP solenoid to the 5th pin of the relay which will activate the LP while the GP's are heating. this will help prime the fuel system. 96+ already has this feature built into the PCM to prime the pump. 95 and earlier doesn't.
Click to expand...
The GPs are only a couple months old. They are Bosch not AC Delco.

So with the GP override, do I just guess how long the plugs should heat?

Is there a wiring diagram somewhere for that relay mod? The only one I’ve seen does not include any connection to the GP relay. Would it work with the GP push button override?
 
revyd said:
The GPs are only a couple months old. They are Bosch not AC Delco.

So with the GP override, do I just guess how long the plugs should heat?

Is there a wiring diagram somewhere for that relay mod? The only one I’ve seen does not include any connection to the GP relay. Would it work with the GP push button override?
Click to expand...
Do not follow the schematic for the lift pump relay upgrade that you will most likely find online.

Don't cut and splice anything

Make it plug and play - like Leroydiesel.com

14 gauge wire

Many years ago, I posted the connectors needed to the lift pump and lift pump harness. I've used the old plug off valve lift pump for that end and just installed new pins.

I prefer a mountable relay socket to a mountable relay. The last time I installed a mountable relay, it was only there for a few days or less. I wanted to pull it and jumper it or something, ended up taking it out and installing a mountable relay socket instead.

I also add a safety toggle switch to run the lift pump on demand.

Anymore, I would just buy Leroy's and change the thingsvI don't like. Faster than starting from scratch & I hate crimping the relay connectors

I'd test your whole glow plug system.

Test each glow plug. At each connector

There has been some issues with the Bosch glow plugs and cko/Chinese Knock Off issues with both brands
You have to buy from a verified source.
I used to get ACDELCO 60G glow plugs at Autozone. I don't know if they still sell them or not.

I'm betting on glow plug or fuel pressure issues, leaning towards fuel
 
White smoke points to injectors. I would assume they are originals and have 250K kilometers (or 155K miles) on them. Been there and old injectors will blow white smoke, especially in really cold weather.

 
Last edited:
Hey Guys,

I know everyone on here loves Leroys. I do too it’s just that I’m in Canada and with the exchange rates and the unpredictable tarrifs, it’s become too expensive to buy his stuff for me.
I’ve got no problem building harnesses or such myself. @jrsavoie Other than the old post with connectors, any chance you know where I can find a schematic for what you are suggesting?
As for GPs, I did a full test just a couple of weeks ago and they all tested fine.
My gut says it’s probably fuel related as well. Hopefully the new gauge will help sort that when it arrives.
I agree that I need to look at new injectors. I’ll put them on the list.
 
revyd said:
Hey Guys,

I know everyone on here loves Leroys. I do too it’s just that I’m in Canada and with the exchange rates and the unpredictable tarrifs, it’s become too expensive to buy his stuff for me.
I’ve got no problem building harnesses or such myself. @jrsavoie Other than the old post with connectors, any chance you know where I can find a schematic for what you are suggesting?
As for GPs, I did a full test just a couple of weeks ago and they all tested fine.
My gut says it’s probably fuel related as well. Hopefully the new gauge will help sort that when it arrives.
I agree that I need to look at new injectors. I’ll put them on the list.
Click to expand...
What would happen if You had components sent to an address in the states, repackaged then sent to You as a gift ? ? ? ?
Would tariffs, taxes and such still apply ?
I have done such as that before. Mailed components off to Canada for members in other forums.
 
MrMarty51 said:
What would happen if You had components sent to an address in the states, repackaged then sent to You as a gift ? ? ? ?
Would tariffs, taxes and such still apply ?
I have done such as that before. Mailed components off to Canada for members in other forums.
Click to expand...
I’m sure that might work. However right now our postal service is on strike and I have no idea when it will be back.
 
revyd said:
Hey Guys,

I know everyone on here loves Leroys. I do too it’s just that I’m in Canada and with the exchange rates and the unpredictable tarrifs, it’s become too expensive to buy his stuff for me.
I’ve got no problem building harnesses or such myself. @jrsavoie Other than the old post with connectors, any chance you know where I can find a schematic for what you are suggesting?
As for GPs, I did a full test just a couple of weeks ago and they all tested fine.
My gut says it’s probably fuel related as well. Hopefully the new gauge will help sort that when it arrives.
I agree that I need to look at new injectors. I’ll put them on the list.
Click to expand...
Since you sound familiar with doing a relay unplug the lift pump. Run wires back from the plug that supply the lift pump, that hot wire will go to the exciter on the relay.

Then run back from the relay to run the lift pump.

That eliminates the cutting and splicing.

Basically, you can use whatever schematic for the lift pump relay upgrade you find. This will just change your to and from and make a cleaner installation
 
And a momentary switch can be added to the relay harness system, that can be used to purge air from new filter installations.
Here is a simple relay system.
1760141757002.png
 
And here is for a five pin relay switch.
Someone smarter than Me will have to explain which circuits needs to go to which pin.
IIRC, 87A is hooked to the momentary switch then is spliced into the live line to the LP.
 
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