Hello crew of FTE,

So I've been having a couple of hard starts if I let the truck sit over a couple of days. The symptom is that the truck starts, idles just fine, then starts to run rough, and if It's sat more than a week, it will usually stall

I hooked up AE and saw that when the engine started to run rough, the injector pressure went *up*. As it started to smooth out the injector pressure went back down to the normal ~450-500 psi range. After that truck runs great.

At first I thought "LPOP" but seeing the injector pressure go up, I'm not so sure. So my next idea is that it's starved for fuel. I do have a leaking lift pump. I've already got a replacement but I need to *find* a driveway or garage I can work in. (We live in a codo with no garage).

Could the fuel be leaking back into the tank slowly due to the FP leak? I suppose if fuel can get out, air can get in.

 

I bet your HPOP res is leaking down. Let the truck sit for a few days, pull the plug off of the top of the reservoir, and see where the oil level is.

I use an unbent metal coat hanger I have in my tool box as a dipstick.

 

Well I could check, but I thought the 96 and 97 HPOPs didn't use a checkvalve anymore and they switched to a standpipe. Does a leaked down HPOP cause a hard start or rough running right away?

 

I think it still has a check valve in the timing cover. If it starts right away then that's not your problem. It sure doesn't hurt to check the level like Jarrett said though.

 

Perhaps I should have started with this but here is the graph of this morning's start. I marked where it started running rough. I thought that if the HPOP isn't getting oil that pressure would go down, or is this metric the desired pressure? In any case it felt like it wasn't getting fuel, very rocky engine for the few seconds this happened. Is it still likely a HPOP reservoir issue?

 

So this morning (After sitting only one night) The truck started with no issues whatsoever. What are some good tests to help me narrow this down? I checked the HPOP oil level this morning, but of course it was fine.

Thanks

 

Good graph, thanks for sharing. Bet it's a fuel pressure issue (maybe pump). Any fuel leaks in the valley? Have you checked fuel pressure at idle?

 

Yes there is fuel in the valley, I already got another pump and bowl, I just have to find time to get it installed somewhere. (Can't do it at home). Do you guys have a good fuel pressure gauge you can recommend?

 

Sorry to keep bugging you guys, but can someone tell me a reasonable fuel pressure tester that can be used on diesels. I've been to three auto parts stores today and they are all gasoline only. I would love one with a long enough hose to be able to be used in the cabin, but for this issue It's probably not necessary.

Thanks

 

You can use a cheap pencil type tire gauge on the Schrader valve. You need the engine cranking over to get fuel reading.

 

I think I'm going to need an actual gauge for this, because it starts up, runs great, then starts to stumble (If I wait over a week it often dies, then it takes a while to get it started again) then it goes back to normal. So if it is a fuel problem the pressure is probably just fine at start, then goes low, and then comes back up again. I don't mind going out to buy a gauge, but all the fuel tester ones I can find online all say not for diesels.

Do people use the gasoline only ones anyway? I'm not sure if it's dangerous or if it just brakes the gauge early. I've seen one person say to use an oil pressure gauge. I guess remembering the fact that diesel is oil that makes some sense except I need it to connect to a shrader valve. Part of the problem here is if I start it once, then it's fine until the next episode so I need to "catch it"

 

Have you changed out the leaking fuel pump yet? If not it could be letting the fuel leak back. The old IDIs were notorious for hard starting when air intrusion was involved. They would fire right up, then stall, and then took a lot of cranking to get them running again. I haven't heard of this on a Stroke, but anything is possible.

 

No it still has the old leaky pump, and I think the fuel bowl is leaking somewhere too. I got a new pump and bowl and all the hoses, etc. to replace. I have to find a driveway or DIY garage to get this replaced. Can't do that kinda work at the Condo. I guess I wanted to verify it's a fuel pressure issue and I would be more confident that my already planned work would fix it.

I'm tying to get everything I need so I'm not leaving the truck stranded when I start the work. Sucks not having a garage or driveway

 

I'm really struggling trying to find a diesel fuel pressure tester gauge. I've come up with one on ebay that says it's for both gas and diesel but I can't find which brand it is so I'm having trouble being sure that's true:
Petrol and diesel fuel pump pressure Tester / Meter 0 - 140 PSI

The other is at my local O'Reillys but it says no diesel in the manual
Bosch Fuel Pressure Tester Kit and the manual

The others from the local Autozone and Napa. say pretty much the same thing as the Bosch. Even the one from Harbor Freight which is pretty far from me anyway. Those of you who have gotten a fuel pressure tester, what did you get? I just want something I can just screw in the shrader valve and read the results. Thanks

 

Just get anything that fits and is cheap. If you were going to use it 100% of the time for years then yea, you would probably want diesel rated. My assumption is you are using it for troubleshooting only at this time?