Sorry to keep this thread going but I bought the pump and wasnt confident in the filter they grabbed for it. Is there a part # for that laying around as well?

 

Background (so you don't have to re-read the entire thread): I've been having slow cold starts, they take an extra 2 or 3 turns to start up. After starting, for the first 30 seconds or so, there is no power. I can barely get anywhere and idle speed is as fast as it'll go. Giving it gas results in back fires and usually slows it down instead of speeds up. After 30 seconds you can hear it come back to life and have usable power again but it is still a lot less than it should be. On the highway especially on hills if it runs over about 2500 rpms for too long it loses power again. Due to this behavior I suspected a dying fuel pump and opted to do a rebuild with a new pump rather than spending 20% of what I bought the truck for, for a new assembly.



Ok so I bought the airtex pump and pulled everything apart just to find out that the airtex pump has a different electrical connector on it. Never mind the fact I couldn't get the old pump out of the assembly. From the information I gathered, this should have been a direct plug and play replacement and an easy job but turned out to be a no go. I just ended up breaking down and buying a new pump assembly.

Now the issue is getting more annoying. When I put a fuel pressure gauge on after a cold start (started long enough to back it out of the garage + pressure loss form attaching the gauge), it read 0psi. I turned the key to the second position and it goes up to 20psi. When I start it it goes to its specified 50psi. During quick revs, it stays at 50psi and still does backfire for the first few seconds.

I dont want to install the new pump unless theres a very very strong chance that it is the issue. I called mike and he suggested I try priming the pump cold a few times and see if it brings it to pressure without backfiring afterwards. If anyone has any other possible ideas on things to try or whatever please share as I'm out of ideas at this point.

 

Maybe post the model number of the Airtex pump here.
Mike has good advice about priming the pump.

Check for pending codes.

If you put the pump into the Assy yourself and sort of hacked it in there.
You may have an issue with pressure loss in the beginning due to a bad physical connection - pump to hose..
Did you put in new rubber fuel pressure hose and not vacuum hose?
Fuel pressure rated hose has a webbing you can see when you cut the hose and look at it that way.

On the bottom of the airtex - it needs to have a tight connection to have a suction vacuum to suck the gas off the bottom of the tank.. Do you think that connection went well???

The Airtex itself may be funky.

You could try this...
Find the fuel pump fuse.
Pull it out.

Put a 10 amp Volt Ohm meter across the fuse connection in the 10 amp mode.

Start the rover.
The Amp meter should remain CONSTANT and not really move.

If it does move around then two things are happening:

1) Either the pump is simply bad..

2) The pump will take more power when there is a load on it - more amps.

3) If the pump can't get gasoline - and no load - the amps will move toward less.

I guess the amp meter will not be that useful really.
But, if it is CONSTANT - perfectly steady, then the problem is probably NOT the fuel pump.

Could be your crank sensor going out - which would cause the backfire as the timing is walking around.

When the engine gets hot - the crank sensor heats up and is steady.
A long shot but..

 

I never actually installed it because I didn't want to hack it together. It's still has the original pump that I think is giving me problems in it.

On a side note I also notice that when I try to really give it gas even when warmed up it bogs down a bit then only gives me a tiny bit extra power. It is running at I'd say 50%-60% of what it should be right now. Feels like I'm driving an 18 wheeler with a Prius engine.

 

OK then.
This is good.
Pull the fuse.
Put in the amp meter.

See if the current level varies all around.

If the current level is constant - then your pump is probably good.

IF the current level varies then either the pump is bad - ie brushes on the motor

Or something is changing the flow of gasoline and the flow on the pump.

If the current level is rock steady, then I would venture to say that the pump is OK.

When the truck is cold - try the current meter and watch it as you go.
As the truck gets more steady and runs better, I would venture to say the current will move up an amp or two.

Well, take a look at this:
(just a generic pump I found on the internet)

Bosch 909 Fuel Pump Specs:
Bosch Part Number: 0580254909
Minimum Current: 12 Volts / 13 Amp
Operating Pressure: 72.5 PSI (5 Bar)
Minimum Flow @ Outlet: 39 GPH (148 LPH)
Fuel Pump Location: In-Line


These suckers really draw the current.


You may want to check the ground for the fuel pump - where ever that is,
the fuel pump relay and the fuel pump fuse for good contact.


You may also benefit on putting a volt meter on the fuel pump fuse and see
if the voltage is 13.8 volts or so.