will crank, wont catch. (no start) RESOLVED

g300d · #1 07-21-2016, 01:09 AM

Drove home, pulled into garage, turned off engine.

Decide to move the truck a bit closer to the wall, crank but no start.

Put the gas pedal to the floor and cranked, engine caught just barely, was maybe 400rpm. Died as soon as you let off the gas.

My laptop with INPA is at work and will bring it home and scan tommorow.

In the meantime, what do y'all think it will be?

ETA: Resolved.

*Scanned with INPA and no codes except for MAF, which I expected since I unplugged it while trying to start the other day.

Activated the fuel pump relay via INPA and it was clicking fine.

Removed the top engine cover to access the fuel rail shrader valve. Pressed the valve in and a dribble of fuel came out.

Had someone press in the valve while turning the key to position 2. No increase in fuel flow, looks like pump isnt priming.*

*Put in a new fuel pump, started right up.*

upallnight · #2 07-21-2016, 08:49 AM

Connect a fuel pressure gauge at the fuel rail and see what the pressure is with key on engine off. You should be seeing around 50 psi.

g300d · #3 07-21-2016, 09:37 AM

Ugh, dont have a fuel pressure gauge at the moment, best I will be able to do is check if there is fuel in the rail via the shrader valve.

Will check that when I scan the X for codes later.

upallnight · #4 07-21-2016, 09:42 AM

I don't think a bad fuel pump will turn on a ses or cel light. Only time I replaced a fuel pump in a BMW was in my E34 Touring which only had OBD I, not OBD II.

oldskewel · #5 07-21-2016, 11:56 AM

Quote:

Originally Posted by upallnight

I don't think a bad fuel pump will turn on a ses or cel light. Only time I replaced a fuel pump in a BMW was in my E34 Touring which only had OBD I, not OBD II.

Confirming, since my fuel pump ('01 3.0i) died a few months ago ... it did not trigger any lights.

LeiZ · #6 07-21-2016, 11:44 AM

Just running out of gas when you turned it off?

Just kidding. I'd also say fuel pump. Check fuel pressure first.

Good luck!

g300d · #7 07-21-2016, 12:17 PM

Guys, I was thinking pump too...but when I put pedal to floor and cranked, the engine caught and ran (barely) as long as I had pedal to floor. Makes me wonder as most all fuel pump failures I've had in other cars, the engine wouldnt catch no matter what I did. Did not want to dig into it at the time, shouldve at least checked the shrader valve.

Up, oldskewl, yes, I dont remember a code for a dead pump ever as well, will do the scan in case it isnt the pump.

Leiz, I wish lol! But I have 3/4 tank at the moment, and it will make a pump replacement a bit more difficult if it comes to that.

upallnight · #8 07-21-2016, 02:22 PM

Quote:

Originally Posted by g300d

Guys, I was thinking pump too...but when I put pedal to floor and cranked, the engine caught and ran (barely) as long as I had pedal to floor. Makes me wonder as most all fuel pump failures I've had in other cars, the engine wouldnt catch no matter what I did. Did not want to dig into it at the time, shouldve at least checked the shrader valve.

Up, oldskewl, yes, I dont remember a code for a dead pump ever as well, will do the scan in case it isnt the pump.

Leiz, I wish lol! But I have 3/4 tank at the moment, and it will make a pump replacement a bit more difficult if it comes to that.

Pedal to the floor is telling the computer that you have a flooded engine and not to fire the fuel injectors to provide any more gas. I would just start the engine without touching the pedal.

upallnight · #9 07-21-2016, 02:15 PM

If you have a cheap tire pressure gauge you can turn the key on, use the tire pressure gauge at the shraeder valve to see what kind of pressure you have. Don't smoke while performing this test for obvious reasons. The pump will prime but won't be running if the engine doesn't start.

g300d · #10 07-21-2016, 07:32 PM

Tire pressure gauge! Cool idea, would have never thought of that lol!

I actually have a few pressure gauges laying around but lots higher pressure and wouldnt be too accurate for reading 50psi. Will scrounge around for old tire pressure gauges, I have some around here somwhere...

On the pedal to floor, I dont normally do that, i do it on hard starting cars as a crude preliminary test to see if the problem is fuel related.

As usual work and life getting in the way of diagnostic time, need to squeeze this in.