89 6.2 - slow start

[Electricduane]

hi:

My 6.2 all of a sudden began acting up. When started cold, it is hard to start, runs rough, and usually dies after it does start. I crank it, mash the pedal, then can get it going. Once it's warm, it runs fine and starts up again easily.

This just started. I have owned the vehicle a year or so, it was fine before.

It's now about 80 during the day here (Northern CA), when the "slow start" thing has occurred. So not a real cold start by any stretch.

-It has the glow plug mod, light comes on and Ford solenoid "clanks" indicating GPs are functioning.

-It has brand new Bosch Duraterm glow plugs. I hold the button for 10-11 seconds. Good long glow. I tested the plugs, they light up correctly.

WILD CARD: Vehicle previously had a "veggie oil" kit on it, but I have run many tanks of regular diesel through it, should have purged all veggie oil out of it.

MY GUESSES:

1) Sock on fuel tank sender is clogging up, cold engine is starving for fuel.
2) Issue with 1 or more injectors?

DOUBTFUL:
1) Air leak in fuel line should not correct itself when engine warms up. ??
2) Dying lift pump also would not correct itself when engine warms up. ??

[68Timber]

Are you registered at dieselplace.com? There's a group of 6.2 guys there that are very good trouble-shooting hard start problems. That's where I go when mine gives me trouble. Dieselplace 6.2 forum. That's not meant to slight 67-72 or anyone here, but there's a lot of 6.2 knowledge and experience there and they like to help.

[Electricduane]

Thank you!

[zaccaglin]

Greeting from a former Yuba resident! My 6.2l had trouble starting s few years back and it ended up being the mechanical lift pump, the IP itself doesn't have enough pull to grab the fuel all the way from that tank in the back and get it up to the top of the block. As for the sudden shut off after crank, mine does that anytime the temps are below 80, even here in fl where I'm living now. Then lock is made of cast iron and we'll diesels running by compression need to be warm. Try cycling your plugs about 5 second longer and holding the throttle about half way when you crank. After she starts up release the plugs and continue to hold the prattle and start moving. By the time I reach the end of my dirt road (1/4mi) or the parking lot at work, she's warm enough not to quit.

[Electricduane]

Originally Posted by zaccaglin

Greeting from a former Yuba resident! My 6.2l had trouble starting s few years back and it ended up being the mechanical lift pump, the IP itself doesn't have enough pull to grab the fuel all the way from that tank in the back and get it up to the top of the block. As for the sudden shut off after crank, mine does that anytime the temps are below 80, even here in fl where I'm living now. Then lock is made of cast iron and we'll diesels running by compression need to be warm. Try cycling your plugs about 5 second longer and holding the throttle about half way when you crank. After she starts up release the plugs and continue to hold the prattle and start moving. By the time I reach the end of my dirt road (1/4mi) or the parking lot at work, she's warm enough not to quit.

hi, thanks. From Yuba to Tampa/Orlando, very impressive. I moved here from Mississippi about 12 years ago. Some pros and cons of each, but overall I like it here.

My latest thinking is that the 6.2 problem is a slow air leak into the fuel line. That way the injection pump uses the fuel that is in the pump, then dies. Then I have to crank it enough to get the lift pump to suck more fuel up from the tank. Every single time it cranks, then dies. Then after cranking, it's fine. The diagnostic fix is to pump 4 PSI of air into the fuel line, which should cause the leak to drip fuel so I can find and repair it. I just have to find the time to fix it. . .easier said than done.