B2600i 1992
 

Have a pretty bad misfire in my truck. I have replaced the distributor cap and rotor all spark plug leads water pump radiator maf sensor and spark plugs. I pulled the valve cover and noticed a rocker arm on cylinder 2 had about an 8th inch play up and down while all others were tight. Inspected timing chain looks good. My issue is that when I apply pressure on the gas pedal or release to slow down my truck jerks pretty bad. Sometimes when pressing the pedal it may bog down while going down the road. At a stop I can press the gas pedal about an eighth of an inch and it will bog my motor down. Has a lot of trouble starting up and runs pretty rough. At this point I'm lost though. I have tried all I can think of so help would be much appreciated :)

My 92 b2600i had a similar 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 do have a web site. www.avproecm.com

Are they still doing the ecm repairs because the website looks like some warehouse that sells overstocked items.

I can't find their original page back either. Too bad. My truck is still running great since they rebuilt the ECM. I did find some complaints on a couple of forums that AVPRO had messed up their rebuilds and then refused to warranty it. My guess? They got bought out and the new owners are not the best.

I think that rebuild is just what I need but now I'm just gonna have to try an ecm from a salvaged truck to see if it helps.

Go to B2600i.com | Engine Control Modules G618-18-881, G630-18-881, ECM ECU
From their site (Scotch is a sponsor of MazdaTrucking.com site):
"1 Year Warranty
Every remanufactured ECM comes with a 1 year warranty. If you purchase an ECM and then determine that your truck did not need a new computer, you may return the ECM within 7 days for a full refund less $50 fee to cover shipping and administration costs.

Purchasing an ECM / Core Charge
When you purchase our ECM,s you will also be charged a "Core" charge until you send us your old ECM. Once we have received your core, we will promptly issue you a full refund of the core charge. Our core charge will be $125 for a G618 computer, and $150 for a G630 computer. When adding an ECM to your shopping cart, you must also add a corresponding (G618 or G630) Core charge to your basket. If you complete the checkout without purchasing a Core Charge, we will not be able to ship your unit until the core charge has been purchased.


Free Shipping - Round Trip
Our ECMs include free shipping and core return shipping - a prepaid return shipping label will be included. We will ship either UPS ground, or USPS priority (2-3days) depending on which one will get to you faster. We will make every effort to ship same day for orders received by noon EST and will usually be able to ship same day even for orders received late in the afternoon. If you need an ECM overnight, please add a "Next Day Shipping Upgrade" to your cart before completing checkout."

Apparently they have a typo because under both ecm checkouts it shows G618.

Got a phone or e-mail ? Contact him directly.

I no little about this however I was having the same trouble with my 1992 Mazda
 

I knew, or thought I did, what the problem was but the more I looked into it and talked to others I realized there was too many things that cause those symptoms and I was sure I did not want to take on all the recommended starting places simply because of my lack of knowledge. So i started having them do all the things they said it probably was. Still I was pretty sure it was the intank filter (the little net on the pump) but no one wanted to look because I guess that's rare. I tried to tell people about my stupid attempt at syphoning the tank empty before discovering it had a plug on the tank so I left the air hose sitting in the tank and it sat there for a cpl days. Long story short. They never fixed it so I pulled off the bed and replaced the pump myself. I'm sure that's not what you did and may not be your problem but it really doesn't take much as it wasn't badly clogged visually so I started second guessing but 30 min later it ran fine. I'm not exactly sure how you would check if that was the problem because I knew what the hose looked like when I pulled it out lol. Sorry for the long explanation I hope it helps