Diagnosing 100 start up issue (1 Viewer)

[ElHefe]

Posting up to bounce ideas off the board members.

Rig: 2001 100 series w/ 149k.

Since quarantine started in Illinois, I’ve driven the truck 20 miles total (in ~4 months). I’ve been starting it up every couple of weeks to keep the battery topped up. Two weeks ago, battery ran low and wouldn’t crank. Used a jumper pack and started right up.

Yesterday, I took it to the car wash to pressure wash the under carriage (was going to install lift kit today). This morning, went to start it to reposition for rear spring install, and it will not start up. Cranks really well (no battery or starter issues), just won’t turn over. No CELs. No immobilizer issues.

Started with electrics and fuel. Read the fuse/electrical thread. Swapped the 20A EFI fuse for a 30A fuse. No change (cranks great, won’t turn over).

Then took off the air box and sprayed some starter fluid. Crank and tries to turn over and run. Fuel delivery appears to be the issue. Cracked the fuel filter; no pressure or mist, just residual spillage from the filter. Tapped the tank and tank skid plate with a hammer while someone was cranking and nothing. Was hoping to cause the pump to engage.

What’s next? Filter and pump replacement? Could this be caused by the pressure wash loosening up electrical connection at top of tank for the pump?

 

[FxFormat]

Sounds like a bad fuel pump to me, if you're sure the EFI fuse is good and there's power going to it.

 

[ElHefe]

Thanks Fx. I will triple check the 30A fuse. If that fuse is bad, my understanding is that the starter fluid shouldn’t make a difference (but it definitely did). Is this true?

 

[gregnash]

Yeah usually if it cranks real strong without issue but just won't kick over that points to either fuel pump or immobilizer/EFI fuse issue.

 

[ElHefe]

Sounds like a bad fuel pump to me, if you're sure the EFI fuse is good and there's power going to it.

I bought some new fuses, swapped in a new 20A. Cranked, but did not turnover. Then I turned on the radio while on acc, then cranked and vroom.

 

[EJ Kestler]

I bought some new fuses, swapped in a new 20A. Cranked, but did not turnover. Then I turned on the radio while on acc, then cranked and vroom.

I am having the exact same issue starting with not driving too much since last year. What fixed it?

 

[hickuptruck]

replace/clean your MAF sensor

 

[ElHefe]

I am having the exact same issue starting with not driving too much since last year. What fixed it?

The fuse bypass. You can buy the kit on here.