Cranks but won't start

[Mooseman]

'05+ have the filter on the pump.

 

[coolride]

I've seen pictures of pumps with filters that hang off the bottom, and also filters inside the pump assembly "cans." By "can" I mean that plastic canister that holds gas when the pump is removed.

 

[Mooseman]

I think those are the old type with the sock on the bottom. The newer ones have the filter inside that canister.

 

[coolride]

I think those are the old type with the sock on the bottom. The newer ones have the filter inside that canister.

I pulled the pump and see a filter inside the canister.

When I pulled the pump I noticed the O-ring was inside the tank (wrapped around the body of the pump assembly.) I don't know if the O-ring fell during pump installation, or during removal.

I attempted to reinstall the pump with the O-ring in place and now the lock ring won't engage the tabs. Is this a common problem?

It's a Bosch pump with a green O-ring.

 

[coolride]

Here's a look at the tank flange. It's just tank material (apparently some type of laminate.) There's no "sleeve" type OEM O-ring.

 

[Mooseman]

There should be a channel all around for the o-ring to sit in. Check inside the tank for a piece of plastic or metal that may have fallen in.

 

[coolride]

Yeah, there's a channel for the o-ring. The problem is, the o-ring is so thick that I can't get the lock ring started.

Next attempt I'll lube the o-ring with silicone grease. Maybe that will help it to spread and flatten out enough to get the lock ring down.

 

[NJTB]

That happend to me, too. Wound up buying the J tool (sorry, don't remember the PN) and installed it that way. I do remember there's about 3 for the TB, look it up for your year.

 

[coolride]

Testing the fuel pump harness. With the key on I'm getting 4.9 volts between the grey and the green. Is this correct?

 

[Mooseman]

Is that for the fuel pump? It should have 4 wires. That's probably for the tank pressure sensor. In that case, you should have 5v between black (-) and gray (5v ref). Green is the sensor output.

On the pump plug, it's:
Gray: 12v+
Blk: ground
ppl and orn/blk: level sender output

 

[coolride]

Thank you. Just tested again.

I see 12v when key is on but it quickly backs off to zero. So temporarily,,,there is 12V. During cranking I see 10V.

 

[coolride]

Ran test again, but used a lead to the neg. battery terminal for the ground (reliable ground.)

Same results. Saw battery voltage with the key on, but only momentarily, then voltage dropped to zero.

While cranking it had 10V.

 

[Mooseman]

That is normal. When in RUN, the PCM primes the pump for just a couple of seconds and switches off the relay until you turn the key to START and stays running. Instead on a meter, use something that draws some amps, like a headlight bulb, to see if enough amps go through the wiring. It can happen that you can see a no load voltage but drops off with an actual load. When plugged in, do you hear the pump run while it's priming?

That's pretty low voltage while cranking. Is the battery good?

 

[coolride]

The battery has been sitting for a looong time. So it's a little weak. I'll get it onto a charger tonight. The pump is out of the tank and in a different room but back when it was installed yes, I could hear it prime.

If there's low amps under load, what's the busted component?

 

[Mooseman]

Could be the relay, wiring, connector or fuse contact. They've been known to get loose and/or corrode.

 

[coolride]

I tested both fuel level sensors. The new one (background) is whacked. The ohm readings are all over the place. No wonder my fuel gauge wasn't working right. The old one works fine.

 

[coolride]

Looking at the Bosch paper work now, and wondering how to get a refund from Amazon. I want a better pump. Called Newparts Inc. of Gordonsville, TN (the seller) and left a voicemail. Was told to expect an email reply.

 

[coolride]

For load testing the circuit, I have a bulb wired up as the load. I can do a high beam test, and a low beam test. (now what?)

 

[coolride]

Does the load test have to be done with the pump installed? The problem I'm seeing is that the PCM cuts power to the pump after a moment with the key on. Hard to test like that.

 

[Mooseman]

Unfortunately, that's how the PCM works. What you could do is pull the starter relay and turn the key to CRANK. It will command the fuel pump on while cranking.

 

[coolride]

Thanks. I'm getting. One step at a time.

 

[coolride]

Rigged up a load with the stuff I could find (nails, alligator clips, wire, and scrap wood.) It works, but doesn't look great. This is a low beam load.

 

[coolride]

Load testing completed. I am reading 0.1v negative side and 0.3v positive side. So no problems are obvious. I'm thinking next; get the pump installed and hook up the tank. I'll repeat the load test with the tank connected, but not strapped up.

 

[coolride]

Spoke to Bosch:

Don't buy a Bosch fuel pump (or anything) from a non-approved Online Partner. This seller is offering auto parts on Amazon.

Newparts Inc. 231 Hogan Rd. Gordonville, TN 38563

NOT an approved online partner. Bosch said they are probably re-selling returned or damaged items.

 

[NJTB]

@coolride
Amazing, isn't it. Back in the day, GM had a problem with distributor caps. They were scrapping defective ones, but they kept turning up, then were returned to the store again.
Turns out someone was pulling the caps out of the trash and re selling them.