Running rough lots of fault codes.

Hey everyone new member here. I'm in the need if some experienced help.nI have a b2600i when cold it won't go past 2krpm and hesitates and bogs. It runs sorta ok when warm but sounds like Its missing and fuel consumption is horrible. Cel light 8, 9, 11, 12, 14 and 26 are all on. Where can I start. I can't disconnect the maf sensor the plug seems stuck on there. I inspected the ecu and found it wasn't even bolted on. I saw no visible corrosion but did notice a single stray yellow wire that was not connected idk if it's supposed to be like that. The ecu connections are also on there really good. Also when the engine warms up the cel light goes away momentarily then returns. Idk where to start with all these codes.

Have you done any research on the codes to know what they are? That would be a good starting point.

^^ + 1 on the codes... pull the ECU and have it looked at by a pro. I suspect there isn't supposed to be a loose wire in there.

Well, your fist problem is to figure out what the wire is. Has it pulled loose from the ECM harness connecter? There shouldn't be any wiring inside the ECM unless somebody added it to replace a damaged trace. Either way, there there is a good chance that that is part of your problem, if not all.

As for it not being bolted on, that shouldn't matter as it is grounded through the harness. But you might as well find some nuts and secure it back in place.

No corrosion. Did you look very close around the two capacitors? Sometimes the leakage is really light and can be missed. If you see anything, green patina, light or dark brown stains, anything... on the board surrounding those caps, then you have leakage. Try to get some close-up pics and post them here.

To get the MAF unplugged, you need to remove the little retaining clip. A couple of small flat-head screwdrivers do the trick.




Here are your codes:

8. Air Flow Sensor
9. Water Temp Sensor
11. Coolant Temp Sensor
12. Throttle Position Sensor
14. Atmospheric Pressure Sensor
26. Purge Solenoid

I'm guessing the yellow wire was a repaired trace inside the ECM and the solder joint has come loose. It's unlikely that you have problems with all those sensors. Post some pictures of the caps and the yellow wire.

Awesome thank you!!! I won't be home until tomorrow but I'll post some pics asap. Thanks again.

Good info right there

Just as scotch says, it is highly unlikely that all of those sensors are bad at once, but you can still test their values at the ECU.

If you can get another ECU (A B2200 ECU will work to test it to, as they use the exact same inputs) then do that first.

Ok so I got a chance to look things over again.

First I disconnected the maf sensor to clean it and noticed that one of the sticks in the plug is missing, shown in pics. Idk if it's supposed to be like that but I doubt it. It also seems a little corroded.

Now for the ecu I took a couple of pics of the yellow wire I mentioned before. I also inspected around the capacitors and you can see a bit of dried up brown stuff. Pics below. Let me know what you guys think.

Thanks in advance to anyone who responds.

Other pics

You're not missing a terminal on the MAF. There is not one in that spot on the left. Notice there is no terminal in the corresponding spot on the harness connecter? Just needs come cleaning of the corrosion... on both the MAF and the harness connecter.

The yellow wire goes to the test connecter that plugs into a Mazda factory diagnostic box. I'm not sure if it would cause a problem or not. My guess is not (unless you were using the box.)

You've got a leaker in your computer. Very typical. That is almost certainly the root of your problems.