1986 Mazda B2000 engine performance problems hesitation

Tiny
1989CAMARORS
  • 1986 MAZDA TRUCK

Hey, I have a 1986 Mazda b2000 LX short bed 5 speed manual transmission with only 80,000 miles. It runs great other than my small engine problem. The engine hesitates/shakes/jerks/pulsates when at around 2400 rpm- 3300 rpm when cruising steadily on the gas(this doesnt happen when the engine is cold, only after it reaches normal operating temperature). I checked out a Technical Service Bullitin about the subject on "All Data" and "Shop Key"and it says it needs some new modified parts. The problem is within the EGR System is what it is leading me to? Any help/suggestions would be very appreciative. Thanks alot.V

Do you
have the same problem?
Yes
No
Thursday, February 9th, 2006 AT 12:12 AM

7 Replies

Tiny
GLASSMAN55TB
  • MEMBER

I had B200 that had the same problem. There are three reed valves in the front of the air cleaner that control gases from the exhaust system. They are a dealer item only, well they were when I had mine. It's worth checking into. You also might check the vacuume advance diafram on the distributor this also causes hesitation.
Good luck,
Tony.

Was this
answer
helpful?
Yes
No
Friday, February 10th, 2006 AT 12:52 AM
Tiny
COSMO
  • MEMBER

That sounds like a perfect symptom of the idle mixture solenoid. The sensor cannot be seen from the outside of the carb. The only thing you can see is two green wires coming out of the top of the carb when the air cleaner is off. Let me guess you have a stuble or hick-up around 100kph/65mph?

This could be a good posiblity

Cosmo. Mazda Tech

Was this
answer
helpful?
Yes
No
+1
Monday, February 13th, 2006 AT 8:10 PM
Tiny
1989CAMARORS
  • MEMBER

Yes it does do it around 65mph. Is there a way to test the component? About how much does it cost? What would some other symtoms be? The engine kind of does it (hesitates) around any speed that is around 2000-3500 rpms while I am steady on the throttle and it doesnt matter whether the engine is under load or not it still does it. The only time that it doesnt seem to do it is when the engine is cold/not warmed up. I feel it has to do with the carb. Any more help would be appreciative. Thanks ALOT![/B]

Was this
answer
helpful?
Yes
No
+1
Tuesday, February 14th, 2006 AT 12:35 AM
Tiny
COSMO
  • MEMBER

There is no real way to test this component. It was a TSB about ten years ago. You can replace it on the vehicle, you only need to take the top of the carb apart. This can be done, but you should take it to a Mazda dealer unless you are very very very very familiar with Mazda carbs and their settings, because after this you will need to set-up the carb and all the mixture settings.

Cosmo. Mazda Tech

Was this
answer
helpful?
Yes
No
+2
Tuesday, February 14th, 2006 AT 5:47 AM
Tiny
HELLCAT18
  • MEMBER

My suggestion would be to replace the carburetor with one from another Mazda, preferably one that just found it's way to a junkyard. Most of the cars that are brought in from accidents will have good working components.

Was this
answer
helpful?
Yes
No
Thursday, March 29th, 2007 AT 11:30 PM
Tiny
HELLCAT18
  • MEMBER

Sorry, but I forgot to mention this. My Mazda b2000 had the same problem when I bought it used. The problem turned out to be a broken, cross-threaded spark-plug in the number 3 cylinder. Check that your spark-plugs are all in correctly and gaped, as that WILL cause hesitation in the engine. Also a side note, you don't HAVE to replace the reed valves usually, just take the filters out of the rubber gromit and the metal casing (don't worry about breaking anything but the rubber if it's dry, they are made to come apart) and wash out the filters with a strong anti oil dish soap. They should be a light brown when clean. When they are dry, put it all back together and fire it up! You should see a noticeable improvement in performance if they were oily or full of dead bug parts.

Was this
answer
helpful?
Yes
No
+1
Friday, March 30th, 2007 AT 5:25 AM
Tiny
86MAZDAB2000
  • MEMBER

Hi, I realize this thread is older. I am having the same issues, jerking, hesitating, occasional stalling at lower RPM, but only in gear and driving, from second gear (5 speed standard) to 65MPH in 5th. It seemed like vapor lock at first (100 degrees) but then just does it even with the engine temperature and weather cool. I replaced the spark plugs and ignition wires. I am having a hard time finding the reed valves, to clean or replace (at the front of the air filter housing?) Also, could this possibly be a clogged fuel filter or fuel pump failing? Just curious what my next steps should be. Thanks for any help you can provide, I appreciate your time. :) P.S. It has a new timing belt, water pump, starter, coolant hoses, thermostat, not that this is relevant, just trying to supply information.

Was this
answer
helpful?
Yes
No
-1
Wednesday, August 8th, 2012 AT 2:51 AM

Please login or register to post a reply.

Other Questions