Hi, I'm new to my mazda truck. It is a '92 Mazda B2600i 4X4. It reciently started acting up and I'm thinking first step, change fuel filter. I crawled under it with my flash light and I found the fuel line but I'm unable to find the filter, did they put it on top of the fuel tank? If so, do I have to pull the tank down to get to it?

WoodSpinner

 

the filter is in the engine bay, passenger side, top of the motor near the fire wall, very near the pass back corner of the intake manifold.

Its fairly large and easy to get to, mine's a '93 and had a fairly elaborate mounting bracket.

 

Let me first state that I have an '88 B2200, and only have the factory manual for that year. However, I believe rodmanmazdadescribed where the plastic fuel filter is on a carbureted B Series with the mechanical fuel pump, and you state yours is B2600i, or fuel injected. Those and the automatic-transmission B Series use an electric fuel pump. Those are most commonly located undeneath the bed, bolted to a chassis frame rail. My '94 Suburban has that as well, and so does my '98 Frontier. On the Frontier it's not on the outer side, but on the inner side of the chassis frame, so you literally need to get under the middle of the bed and then look to the outside. Personally, I've never heard different from a frame-mounted fuel filter for any fuel injected vehicle.

 

rodmanmazda,
thanks, you hit the nail on the head, I bipassed the filter (parts store not open today) just to test it, didnt change anything. shucks its not going to be as easy as I had hoped. does anyone know what the fuel rail pressure is supposed to be? I'd like to test it before replacing a $130 fuel pump not to mention all the hassle of installing an intank pump.

WoodSpinner

 

My manual says 28 - 37 psi.

You didn't say exactly what is acting up, I've had 2 2600i's (one 2x4, one 4x4) both have had an appetite for spark plug wires.

 

rodmanmazda,
Thank you again, the problem started with a start/die sort of thing, then it would start and run for a while but it would bog out big time if you depressed the accellerator peddle too far down, came up the hill back to my house at like 9 mph. I'm really leaning to like 85% sure its the fuel pump but given my "starving artist" profile I feel the need to run this last pressure test (if I can find a friend with a fuel pressure gauge)so I dont install a 150$ fuel pump (money I really cant afford to spend) just to find out its the pressure regulator or some such.

WoodSpinner

 

oh, my 2wd did the exact same thing for about a day, went away for about 2 weeks and then did it again, ended up being the ECM ($300), I've heard Avpro is the best. I got one off ebay(not avpro)but had to return it for a 2nd.

 

ECM for mine, (1990 b2600i 4x4), too; but I found an ECM on Ebay for 100.00(guaranteed for a year or maybe two from ebay, but it's been 5 or 6 years and still no problems. It was easy to put in, so no labor. Good luck. My vehicle had about 125K on it when the ECM went out.

 

Common problems on those are ECM due to crimp connections in the injector harness making poor contact. The ECM is easy to diagnose, remove it, disasemble and look for a burnt board or capacitor. Replace the injector harness if so. Seen lots of bad MAF that act as you describe too. Fuel pump is possible since it is pretty old. Add Marvins mystery oil to the gas tank to lube the pump. If it is trying to lock up the oil will make the symptoms go away.

 

My 92 b2600i had the exact same problem. I checked the fuel pump with a pressure gauge, replaced the regulator on the injection rail and changed the firewall mounted gas filter. Nothing. Would not start.
I started digging around on the internet and found that this is a common problem on older cars using the same ECM that our trucks do.
I contacted AVPRO and they rebuilt my ECM. When I got it back, I put it in the truck and it fired right up. That was 3 or 4 years ago, and it runs like a top. Here is an email I received from them at the time:

support@av​proecm.com

Hello, the computer you are looking for is so rare people are breaking into cars to steal them. The only unit we have we are using for parts. The cost to repair that ecm is $160 US, $195 Canada (price INCLUDES return priority mail). If ecms arrive before 11 AM we have time to process them and get them sent out the same day via USPS Priority mail. The warranty is for as long as you own the car. Priority to AvPro, P.O. box 6612, Fort Myers Beach, FL 33932 is the best way to send to us as we are on an island and other carriers do not get here until after noon to as late as 10 PM. PLEASE include name, address and phone # inside the box with the ecm.

Business checks or certified payment only. No credit cards. Postal M.O.s cost about a dollar. These should be included with the unit or C.O.D. charges will apply.

Thank you for the email. Any other questions please call or send your phone #. Nick

Just for clarity, what we sell is a lifetime warranty. If a unit arrives here we HAVE to determine a problem before it can be repaired. If the unit is still operational we will make upgrades to insure it will CONTINUE to work in the future and we are confident enough to warrant it as long as you own the car.(Truck)"

Contact them first, as prices may have changed. They brought my truck back from the dead, hopefully, they can help you. They may be your only hope. A used ECM will eventually FAIL. That is money down a rat hole.

They do have a web site. www.avproecm.com