I'm considering an 89 fuel injected 318 truck. Wondering if things turn to junk on it, will I be able to switch to a carb and mechanical fuel pump setup. I realize the tank would probalby need changed, mostly wondering if I had to, could I mount a normal 318 fuel pump to the block or not? I haven't seen the truck in person yet, so I wanted to ask first.

Thanks

Well, I don't know why you'd want to run a mechanical pump when you already have an electric pump in the tank. You just need a pressure regulator with a return line, and your setup probably already has a return line. TBI system fuel pressures are normally from 13 - 15 psi, can be regulated down to 5 or whatever pretty simply.

R.

the t-cover should have a block off plate where the FP would go.

the cam will be a short nose roller cam and no mech fuel pump ecentric.

you can get an adaptor/extintion piece from hughes to go on that cam so a mech fp will work.

or

replace roller cam with a long nose aftermarket cam.

or

you can tap into the wireharness to run the intank fp but will need a pressure regulator up by the carb to cut the pressure down to 5-6 lbs.

when converting to carb you need to look and see if the wireharness under hood has a VR on the firewall... if not when you by-pass the pcm to run carb you will need to wire in a VR to by-pass the pcm alt charge control as well

those 2 things should let it work with out any problems. this will also leave it mostly intact and not have the shadetree whack and hack to the harness.

oh! and if you remove the tbi intake and throttle body for a carb you will need to swap out the throttle valve bracke/linkage to the stock carb kickdown linkage.

Thanks y'all. Sounds like it'd be about as easy to just go 440 if it all fails and I have to start replacing stuff.

I don't see where everyone is so hung up on mechanical pumps. Most people don't even understand how they operate.

Now if one used a Holley electric pump and the matching Holley regulator that'd appear to be pretty normal. But replace the Holley electric pump, which will pump at around 13 - 15 psi, with an in-tank electrical pump at the same pressure and it gets too complicated to deal with?
Believe me, replacing a fuel injected 318 with a 440 in a 4WD truck is nowhere as easy as wiring up a distributor, plumbing in a carburetor and regulator, hanging on the correct linkage, and possibly adding a voltage regulator.

My '93Suburban has 253K miles on it and the TBI still works. The Delphi/Delco system can't be THAT much better than what's in a Dodge!

R.

I didn't see 4wd mentioned. A 440 swap is rather easy If you have everything needed. As stated no need to ditch the fuel system if swapped to carb. plus probably cheaper to replace the electric fuel pump than to by a mechanical pump the snout extension gaskets tank fuel line.

Wht do you want to change from the TBI to carg? What do you expect to gain?

He said if system "Fails"

Correct me if I am wrong, but don't the LA motors use a bolt on fuel pump eccentric that fits on after the timing gear? So there is no lobe on the camshaft itself.

Its been a LONG time since I was into an LA motor, so my memory could be failing me.

Yep! its a bolt on piece. Not sure if it would fit directly onto the cam/timing gear but it does bolt on.

Ahh I see what scratch is saying, the cam doesn't have the tabbed end to fit the eccentric.

Found the part at Hughes its a $26 deal

That guys right. The Walbro factory pumps run a long darn time. And the 89 still had replaceable in line filters too.

1989, 1991, 1993 cars that i owned the fuel pumps lasted around 120K miles. Two were MPFI 40 psi, one was TBI, 13-15psi.

I also like Walbro pumps.

If yer worried about it, run the darn thing almost out of gas and change the freakin pump. Most of them come in kits with new tank level sensors and of course inlet filters.

R.