Hi,

I have a Mazda 323 (model BJ, engine type ZM) manufactured in Dec. 2000. Since of late it has developed a strange engine trouble.

This trouble comes from time to time, say, about every week or so. When it occurs, the engine keeps on "knocking" and I can observe that however much I accelerate the rev meter goes down. Then suddenly it jumps and the revs pick up. So the car keeps on "jerking", but the engine never stops. This jerking keeps for a while and then it automatically becomes normal. I have noticed that if I turn off the engine few times it recovers faster, but if I keep running it takes longer to recover.

It's been about 3 months since I first got the trouble. Since then I have done numerous repairs with out any success. I have taken the car to the local Mazda and Ford agents (this model and the Ford Lazer are the same inside). All computerized checking done by them says that all sensors are working correctly. (I did the computerized diagnosis 3 times). I have replaced spark plugs andboth ignition coils. Since the car has done about 96,000 km, I replaced the timing belt as well. All electrical contacts were checked and cleaned several times.

Can anyone think of what's wrong here? Any help is greatly appreciated.

Thanks,
Ishan.

 

try cleaning your maf sensor and egr passages

 

have also seen wiring breaking in the harness around the top of the trans. area. wiggle the harness while the engine is running to see if there is a change

 

Hi,

Thanks for the reply.

I did clean the MAF sensor. But what is the EGR pessage? Is it part of the throttle body? I got thethrottle body cleaned as well.

Please parden my ignorance... can you tell me how to locate the transmission area? Can I access this from under the hood or do I have to take it to a mechanic shop and have it hoisted to wiggle the wiring harness?

Thanks in advance,
Ishan.

 

Hello,
A common problem that gives this symptom is the trottle body air flap getting stuck closed. Remove inlet air hose from the throttle body and check for flap sticking. If the case, remove existing groove made by the flap on the throttle body with some fine sandpaper (400 grit). Clean thoroughly with intake cleaner spray afterwords. A misfire code could be set after running the engine due to the cleaner spray.

Good luck.