I've been driving my 93 a lot here lately. It sat previously for 2 years but seems to be running great. Starts good and idles great. Has 169,xxx miles. My uncle wanted to hear how it sounded with the stack so I started it. It ran fine then acted like it choked itself out and died. It cranked over a time or two and fired right back up, no smoke or anything. Sounded fine after that and ran good as ever. I drove it about 45 minutes to my uncles so it was warm when I started it for him. Anybody know what would cause this? Maybe lift pump getting weak?

 

Pretty easy to crack open the t valve and see if the LP has good pressure. After sitting 2 yrs the sock in the tank could be coming apart, cracks in rubber hoses, small leaks in filter housing/heater, ect. ect.

 

Thanks burnhedge. I'll pull it into the shop tomorrow after work and look it over good. Could a fuel filter do this? It had old diesel in it when I got it, I ran it as low as I could get it before it ran out. Has fresh fuel now so maybe I need to change the filter again? Is their any other fuel filters besides the main filter on the back of the engine?

 

The only other filter is the sock filter in the tank. Their's probably alot of things that could cause it to die one time but definitely check your LP pressure so you don't smoke the IP. Also a good idea to clean and inspect all your grounds since it's been sitting so long.
Hard hot starts usually indicate the IP is failing, but that doesn't sound like what you described.

 

Pulled it in the shop and checked everything out real good. Didn't see anything loose, rotted vacuum lines, or anything unplugged or broke. No wet spots on the engine either, still sealed up tight.
How to I go about checking my lift pump? Fuel pressure guage? Where would I put it to check it.
Also what is the T handle on the front of the engine? I read it was a water drain for the fuel filter. My water in fuel light isn't on but should I try this anyway?

 

The t valve is a small shut off style valve with a t handle. Mine sits right behind the thermostat housing. Open it up with the truck running. You should get a steady flow of fuel out the discharge hose. If not or if the truck dies, then you have a LP problem to diagnose.

IMO a fuel pressure gauge isn't really necessary. A stock LP only pushes 5-7 psi. So if you have good flow the LP is doing its job.

 

Thanks again burnhedge. I think the truck may have just had a hiccup yesterday. Like I said its running good and everything's seem to be operating like it should. Time will tell I guess. Gonna keep on truckin till then

 

Well I tried testing the lift pump. (Starting truck and opening T valve) it killed the truck almost instantly. So I'm picking up a new lift pump tomorrow. Any tips/tricks I need to know? Or is it fairly easy to change out? My first time replacing one.

 

Test the lift pump before you buy a new one. Just as likely that your OPS is bad. Or the relay. Tons of info on LP diagnosis on this forum.

Changing it out is a breeze

 

Thanks again burnhedge. I got a lot of reading up to do on these engines. Would a bad OPS mess with the oil pressure guage?