Engine/Transmission (1998.5 - 2002) Hard cold start, '01.5 HO

[jmeehan]

I spent the last two nights in Taos, NM. This is the first time in 55K miles my truck has spent more then 6 hours shut down in those temps, at that altitude. Mid 20's, approx. 7500'.



Both mornings the truck didn't fire up on the first crank. It started on two or three cylinders, I do not have the cold weather idle enabled. Yesterday morning I fed it some throttle and all cylinders came on line and it idled and ran fine. This morning, while trying the same trick (which did not work this time), I noticed I had no fuel pressure. I think the cam sensor wasn't seeing enough RPM to turn the pump on. I shut the truck off, bumped the starter twice to build pressure and it started up like it always does.

I'm using an anti-gel additive, and it starts and runs great all the rest of the time.



My first thought is a check valve in the fuel system, like the 12 valvers have. I've never heard of one on the 24 valve fuel system going bad. I'm in Albuquerque now, leaving for home on Sat. I hope it's nothing serious, but I don't want to get stuck if the problem gets worse.



Any thoughts or suggestions? Thanks, Jeff

 

[GOT-Torque]

So you have a fuel pressure gauge? No fuel pressure is not good. Either the lift pump failed or fuel gelled up and plugged the filter. If the lift pump failed I would not drive it very far as you will damage the injection pump ($$$$$ repair) vs. less than $100 for a lift pump.

 

[jmeehan]

So you have a fuel pressure gauge? No fuel pressure is not good. Either the lift pump failed or fuel gelled up and plugged the filter. If the lift pump failed I would not drive it very far as you will damage the injection pump ($$$$$ repair) vs. less than $100 for a lift pump.

Yes I have a pressure gauge. The pressure came up once it was firing on all cylinders. The only time I saw no pressure was when it was coughing and sputtering on two or three cylinders. I think the cam sensor was not seeing enough RPM to tell the computer to energize the pump.

When I bumped the starter the pump energized and the pressure was good, both pre and post filter. I installed two sending units so I could keep an eye on the filter state i. e. plugged with gelled fuel or sludge.

 

[GOT-Torque]

No check valve that I am aware of on the stock system. If you still have the stock lift pump, it doesn't matter if it is running or not. I'm pretty sure the engine will start and idle with 0 pressure.



Your scenario sounds like when I start my engine after an injector changeout and there is air in the lines. It takes some throttle input to get it to idle until all the air is out of the lines. Maybe by bumping the starter a few times and letting the lift pump run, it purges the air out of the lines, therefore it starts and idles fine?

 

[jmeehan]

No check valve that I am aware of on the stock system. If you still have the stock lift pump, it doesn't matter if it is running or not. I'm pretty sure the engine will start and idle with 0 pressure.



Your scenario sounds like when I start my engine after an injector changeout and there is air in the lines. It takes some throttle input to get it to idle until all the air is out of the lines. Maybe by bumping the starter a few times and letting the lift pump run, it purges the air out of the lines, therefore it starts and idles fine?

That's the same thought I had too. When I installed both sets of injectors it started the same way. I was hoping it was related to the cold and altitude, but I'm beginning to doubt that.

I'll check the codes, dig my manuals out from under the camping gear and see what I can see.

It still runs good after all cylinders are firing, and it starts good after that first cold start in the morning. If it is the injector pump I hope it will make it home (I think it will), then I can tear into it. I do have a spare lift pump, but I don't think that's it.

 

[jmeehan]

Well I have no codes, and it starts slightly easier on a downhill slope. I think it's the overflow valve, now I just hope I can find one in Albuquerque.