Hard starts and more

[aaron1976]

I have been driving my 87 ford f250 for a while now and have come upon a new problem. Lately when I go to start the truck it will fire then die within a second or two. After that I have to crank the engine for a while and push on the go pedal while cranking. After some cranking it will fire up but run rough/miss for a while. Sometimes when the truck is idleing it will start to miss as well.

After I have drivin it for a while and I shut it down for 5 minutes or so it does the same thing all over again.

Also I have noticed that after I have started it when it's cold out and drive it for a bit, while at a consistant throttle the engine will surge and all of the sudden have a lot more power. When it does this I can hear the turbo spool up more as it is getting more fuel. The power seems to come and go.


I have noticed these symtoms since it has been cold here in Wyoming. I use the suggested amount of winter diesel treatment to fuel ratio for the temps.


I am thinking possibly the lift pump? It's pobably time to do everything, injection pump and injectors.

I have done the return lines.

I have also changed the fuel filter twice in the last week just in case. Both times it has only been about 2/3 full of fuel.

Thanks for the help

 

[LCAM-01XA]

Aaron, you mention the return lines - you're on the right track with that comment, only it ain't the return lines causing you trouble, it's supply line to the lift pump. See, leaky return lines only prevent starting, but once the truck is running the fuel pressure pushes all the air out and either starts leaking through the disturbed seal, or just reseals it for as long as the engine is running. When you have an air intrusion in your supply line tho, then the lift pump sucks air in along with the fuel, and when the air bubbles reach the IP they throw it's internal presssures off causing it to advance the timing a lot and you see this as a short burst of power if the bubble is small, or as a stumble and misfire if the air bubble is larger. The air intrusion can be at your lift pump, yes, and at $26 for a brand new made in the USA pump by Airtex it's a good idea to replace your aging pump anyways, but what I'd suspect as a culprit is either the rubber hose that goes between the lift pump and the steel line on the frame rail (the rubber dries out and cracks), or it could also be the steel line itself usually where it runs under the engine or along the stretch that's on the inside of the driver-side frame rail. If it's indeed the steel line leaking, it's a 3/8" line and you can buy some 60" pieces of 3/8" line from Autozone for like $6-$7 and then bend them as you wish. If it's the hose, it's a 3/8" hose too, and needs to be coiled, as in when you connect it to the fuel line make a full 360-degrees loop before you cut it down and connect the other end to the lift pump, this accommodates for the engine twisting in the motor mounts under heavy throttle.

 

[aaron1976]

I will be done. I will replace the lift pump along with the rubber hose that supplies it. Also will see if I can track any leaks or cracks in the metal line.

I appreciate the info a lot.