87 B2200 surging/hesitating???

[pvtcook]

Just bought a 87 bseries. The truck runs fine @ lower/higher rpms. Its at the mid rpms that it feels like its kind of hesitating.(jerky acclereration in 1st/2nd gear) If I push it on down it does fine. I unhooked the EGR and plugged the line and that seemed to help but not completely. It is also alot worse when the engine is cool.
Im new to Mazdas and would appreciate any help.
Thanks

[Foodgod1]

Originally Posted by pvtcook

Just bought a 87 bseries. The truck runs fine @ lower/higher rpms. Its at the mid rpms that it feels like its kind of hesitating.(jerky acclereration in 1st/2nd gear) If I push it on down it does fine. I unhooked the EGR and plugged the line and that seemed to help but not completely. It is also alot worse when the engine is cool.
Im new to Mazdas and would appreciate any help.
Thanks

I have a 1988 B2200 that does a similar thing. It bucks and jerks when you accelerate between the gears 3,4, and 5. I changed the EGR, O2 sensor, tune up, cat with new exhaust, etc and it is still doing it. The carb is 4 years old. Don't know where to go from here. I have seen othe postings like ours with no help from the group at all. Are you still having your problem.

[pvtcook]

Man I didn't get any help either. I took it to a couple of mechanics and they said the carb needed rebuilding. I fixed mine though. I got me a 91 Ford Ranger, you just cant beat that fuel injection. Parts are a dime a dozen for my Ranger whereas hard to find for the Mazda. I hope you find the problem though.
Dee

[Foodgod1]

Originally Posted by pvtcook

Man I didn't get any help either. I took it to a couple of mechanics and they said the carb needed rebuilding. I fixed mine though. I got me a 91 Ford Ranger, you just cant beat that fuel injection. Parts are a dime a dozen for my Ranger whereas hard to find for the Mazda. I hope you find the problem though.
Dee

In case anyone gives a hoot at this point, I disconnected the map sensor and the truck runs fine now. I don't know if the sensor is bad or if the computer is compensating for the unplugged sensor be closing the loop and by passing the sensor. Anyway, I have a used one on order from a salvage yard as I don't want to pay 240 bucks for a new one. Oh yea, the mechanic that checked it out said it read fine on the computer check so we'll see when I put the other MAP sensor in provided it is a good one. Kind of odd that when I unplug it, the truck runs like a champ though!

[russiankid]

Originally Posted by pvtcook

Man I didn't get any help either. I took it to a couple of mechanics and they said the carb needed rebuilding. I fixed mine though. I got me a 91 Ford Ranger, you just cant beat that fuel injection. Parts are a dime a dozen for my Ranger whereas hard to find for the Mazda. I hope you find the problem though.
Dee

or if you are so inlove with your mazda im pretty sure you can put a ranger engine into the mazda b-series trucks, i mean they are pretty much the same

[razor34]

I had the same problem with my 91 B2200.I replaced a pressure sensor that is on the passenger side near the wiper motor and it runs great now.

[Foodgod1]

Yes, that is the MAP sensor. They are about 275 bucks. When I disconnect it, the truck runs fine. I have one coming from a salvage yard, so I hope that fixes it. Is your 91 Mazda fuel injected or carburetored?

[razor34]

Mine is carburetor.

[mrzub]

Originally Posted by Foodgod1

Yes, that is the MAP sensor. They are about 275 bucks. When I disconnect it, the truck runs fine. I have one coming from a salvage yard, so I hope that fixes it. Is your 91 Mazda fuel injected or carburetored?

Where is the MAP sensor Located?

[mrzub]

Originally Posted by mrzub

Where is the MAP sensor Located?

Nevermind. I found it. Disconnected it and got no positive results. I also changed the fuel filter and no help.

I think the problem lays in the Carb. There is a choke diaphram that is getting stuck.....i think will replace it....

wish me luck.