Help me troubleshoot. Explorer efi problem.

[Boss Hugg]

I had posted a complaint about my Bronco not downshifting at hwy speeds. It turns out the engine is just laying down with more throttle. Explorer efi, stock 5.0l. No codes, no CEL. The video at the link is with me sitting still in the yard. Tell me what it sounds like to you. You're listening for the stumbling at random places.

 

[Yeller]

Fuel pressure falling off?

 

[Boss Hugg]

Fuel pressure falling off?

It would have to be a sporadically bad fuel pump. And the failures I've experienced, when they quit, they quit. Some can be bumped to make work again, but when they quit, they quit.

I pulled out on the highway thinking I could ease around on the roads, but I got to about 35 and it laid down. So I pulled over to let it catch up so I could turn around. It ran fine all the way back to the house. I'm thinking coil packs have gone bad.

 

[Yeller]

I was thinking more like pressure regulator. However coil packs seam reasonable, just never seen an explorer coil die, not say it’s not possible. Like fuel pumps they work or they don’t typically.

I’ve seen explorer engines do some weird thinks without a check engine, run with no accessory belt, no charge, get hot enough to steam after driving for 30 miles in that condition, fan was spinning enough to keep it from melting down.

 

[Boss Hugg]

Check this out.

 

[Boss Hugg]

Check this out.

But I pulled out on the highway again and its still not running right.

 

[Boss Hugg]

Can a fuel filter cause this problem? It was changed to too many miles ago. And I don't have a way to set up a fuel pressure gauge to watch while I drive.

 

[Yeller]

Could explain he intermittentness and with a steady load on it run out of fuel. If your have a fuel sock on the pick up, it can do that as well. In extreme cases I’ve seen unvented fuel tanks do the same, or in that case the purge solenoid failed and the tank was not venting through the charcoal canister.

 

[Boss Hugg]

I'm so sick of this happening.

 

[Yeller]

That’ll do it

 

[Broncobowsher]

That's not a proper fuel line hose clamp. And I am willing to guess that isn't a proper submersible rated fuel hose either. https://www.gates.com/us/en/fluid-power/engine-hose/fuel-line-hose.p.4219-000000-000012.html

And the clamps as well https://www.gates.com/us/en/fluid-power/engine-hose/fuel-line-hose.p.7400-000000-000000.html

 

[Boss Hugg]

Correct hose and clamps are on their way. Yay.

 

[spap]

Double up on the hose clamps

 

[Tiko433]

Not sure if you had to splice anything on the harness. If so check them. I chased a problem like this for a year. I checked a changed several parts. Turned out I had a bad splice on my MAF pigtail.

 

[Viperwolf1]

I like the convoluted nylon tubing and pinch clamps inside the tank. It lasts forever.

 

[Boss Hugg]

Not sure if you had to splice anything on the harness. If so check them. I chased a problem like this for a year. I checked a changed several parts. Turned out I had a bad splice on my MAF pigtail.

This was definitely a problem with the fuel pump/hose.

I like the convoluted nylon tubing and pinch clamps inside the tank. It lasts forever.

You mean the stuff in the pic that is the "return" hose? Will it stand up to the full pressure of the pump?

Double up on the hose clamps

Not enough length on the pump connection.



In other news, I sent an update to @EFI Guy and thru his responses I ended up messing with programming and figured out why it wasn't downshifting like it should. I had a bad number for transmission revs per mile. With that fixed, this thing runs like a race car. So in case I find myself having TOO much fun with it, it was great knowing you guys!

 

[ba123]

Yeah, I hadn’t seen the comments and was gonna say that sounds like a lack of fuel problem for sure.

So, does your fuel pump not have a flared end to help the hose stay one?

You def need the right clamp and make sure you have a hose that is one made to be inside a fuel tank, but I’d also use an adhesive that is ok to be submerged in fuel.

What’s your fuel pressure set to?

 

[Boss Hugg]

Everything is stock for the explorer setup minus the EPA stuff and egr. I have the correct hose and clamps on the way. Will get them replaced ASAP so it doesn't happen a fourth time.

what’s your fuel pressure set to?

 

[Bruners4]

Sounds like you have multiple things going on. I'm just starting to drive my Explorer conversion also. Mine shifts too soon and bogs the 5.0. I'm interested in the programing that you did and what you used to do it. You can PM me that if you want to.