91 B2200 Fuel Problem
 

I just bought a 91 B2200 pickup that's been sitting for over a year. Its a carbureted model with the electric fuel pump in the tank. I'm having a fuel delivery problem and need some advice/help. I drained the old fuel from the tank and replaced it with about 4 gal. of fresh fuel. I also replaced the in-line filter. I used a hand vacuum pump at the carb. end of the fuel line and was able to draw fresh fuel through the line. I left the fuel line at the carb. open and cranked it but got no fuel out. I checked the wiring to the pump and found it to be good. I disconnected the connector at the pump and connected it to a test light and there was power present when cranking and then for a few seconds when the key was returned to the "run" position then it when out. I reconnected the pump then disconnected the wire at the fuel controller and measured the resistance to ground from the lead going to the pump and it measuread a low resistance so I appears the pump motor is not open. I then applied +12v to the lead going back to the pump but still got no fuel delivery to the carb. Here are my questions.

- Should you be able to hear the pump running when power is applied?
- Is it possible the pump is mechanically stuck/gummed up and if so does anyone have a creative solution for un-sticking it?

I was hoping to get it going without having to drop the fuel tank but that may not be possible.

Also, I dribbled a little gas directly into the throat of the carb. and it started right up and ran pretty smoothly for a few seconds so I think it will do fine once I can get a steady flow of fuel to the carb.

Thanks in advance.

RE: 91 B2200 Fuel Problem
 

Good diagnostic work. Now all you have to do is pull the fuel tank and replace the fuel pump. While you're at it check the inside of the tank for rust. It is common for B tanks to rust out when left to sit for awhile. You can fix a rusty tank two ways. Replace it with a good tank, or repair it with a POR 15 or KBS tank sealer kit.

HTH

RE: 91 B2200 Fuel Problem
 

Instead of dropping the tank, you can remove the bed, or just tilt up the bed; that's what I did to repair the sender:
Disconnect cable release and the two rubber hoses at the gas fill assembly (loosen and raise bed slightly [see below] to remove the larger one).
Remove the three 17mm-head bolts on the passenger side bed frame.
Loosen the corresponding bolts on the driver's side, about about 2/3 of the way. Use a 16 inch 2 x 4 on a floor jack to lift up the passenger side of the bed Tighten the jack, and up tilts the bed. I used a 1/4 inch drive ratchet, with 1/4 inch socket and a #2 Phillips bit (and two hands to hold it straight). All mine loosened, but maybe because I'm in Arizona there was no rust; I replaced with 7mm head hex head screws (4mm thread x 8mm long, with a wavy washer). To line up the bed so I could get the three 17mm head bolts back in on the passenger side, the bed needed to be jacked up a little, then I could use my weight to shift the bed a little from one side to the other.

RE: 91 B2200 Fuel Problem
 

Thanks for the quick replies. The old gas that I drained was pretty clean looking, it mainly had that old gas/varnish smell so hopefully the tank isn't too badly rusted. Its funny that you mention removing/lifting the bed. When I was trying to get my hand in to unplug the pump electrical connector I was asking myself "I wonder how hard it would be to remove the bed?" It sure would be handy if the factory had installed an access panel over that area.

Regarding a replacement fuel pump, is this one of those parts that is best replaced with an OEM or will an aftermarket work just as well?

JH

RE: 91 B2200 Fuel Problem
 

I've been buying replacement parts for all kinds of vehicles from NAPA, Advance Auto Parts, Autozone, O'Reily's, and Pep Boys for years, and haven't had any problems. With the lifetime warranty on most of the Autozone stuff and due to convenience I usually buy from them, but I've had good luck with all of them. I also like being able to use special tools from Autozone free of charge. I bought my engine rebuild parts from NAPA because they had the best kit prices and the rebuild kits didn't have any better warranty from Autozone or the others.

If the tank is varnished up real bad, you need to remove it and clean it out with an industrial strength cleaner that is designed to remove varnish and contaminants. Check with your parts house, or order it from KBS or POR 15. After cleaning, dry it really good. I used the exhaust port on my Shop Vac. If you don't clean the gunk out of the tank, it will just plug up the filter screen on the fuel pump and you'll end up replacing it again.

HTH

RE: 91 B2200 Fuel Problem
 

Update on the fuel delivery problem. I removed the tank and pump this afternoon and the pump is definitely bad. I also found that the pickup screen was clogged/gummed up. The tank itself is as you predicted - pretty funky so I'll be cleaning it before I reinstall it. I think the pump is just gummed up and perhaps soaking it in Berryman's Chemtool or lacquer thinner might dissolve the varnish and eventually free it up but I'll be replacing it with a new one (and a new screen). Thanks again for all the good advice. I'll keep you posted. JH

RE: 91 B2200 Fuel Problem
 

It's Alive! I got the new pump and screen installed and the tank back in the truck. Poured in 5 gallons of fresh fuel and the truck fired right up. It smokes a bit but really runs smoothly. I took it for a test spin and it drives and shifts well. Now its on to the next project, the brakes. The pedal goes straight to the floor so I've got the get the bottom of that. JH

RE: 91 B2200 Fuel Problem
 

If you need a brake master cylinder, get one with lifetime warranty. And measure the distance from the end to the bottom of the hole where the pushrod goes, and do same for the new master cylinder. If they're different than more than a millimeter or so, you'll have to adjust the brake pushrod accordingly. Use a flare wrench to first loosen and the final tightening of the brake lines into the MC, and don't bend them if you can avoid it. Bench-bleed the new MC. Line up the fittings and hand-thread them several turns to avoid cross threading them. Flush ALL the old fluid out ALL the brake lines when bleeding.

RE: 91 B2200 Fuel Problem
 

I haven't had a chance to seriously troubleshoot the brake issue but I suspect the master cylinder is the main problem. I'll probably get it from the local O'Reilley Auto parts store. On their website they list a NEW O'Reilley brand MC for less than $40 and its complete with the reservoir and switch. That's where I got the fuel pump after checking with a local Mazda dealer. The OEM pump listed for $325 - ouch! The OR pump was $77.

Thanks for the good advice regarding the brakes, esp. the tip about the push rod length. I probably would have breezed right past that one.

RE: 91 B2200 Fuel Problem
 

Well, I got the new master cylinder installed but when I went to loosen the bleed valve on the passenger side caliper, with minimal force it twisted right off. Arrrgh! It left part of the valve sticking up (didn't twist off even with the caliper) so maybe with some penetrating oil and some coaxing I can get it out. jh