1990 MAZDA B2600 ENGINE MISSING

  • Tiny
  • 90mazda
  • 1990 Mazda b2600

Engine Performance problem
1990 Mazda b2600 4 cyl Four Wheel Drive Manual 164000 miles

The engine is missing and I have a loss of power and gas is coming out of the exhaust. Thinking I have an ignition system problem I replaced the spark plugs, wires, coil, distributor cap, and rotor. I also checked the compression it seems to be good. There is a significant amount of gas coming out of the exhaust. Enough to leave a large puddle after 30 seconds of idling. Could the fuel injection be stuck wide open? Could the igniter be bad? Is there any way to check the igniter?

Friday, March 19th, 2010 AT 10:48 AM

54 Answers

  • Tiny
  • KHLow2008
  • Expert
  • 41,976 posts

Hi 90mazda,

Thank you for the donation.

If the igniter is bad, you would not be able to start the engine so that should not be the cause.

The more likely cause would be a bad injector that is stuck open. Try to determine which cylinder is not working correctly by pulling out the spark plug wires and noting which cylinder causes the least change in idling speed.

Was this
answer
helpful?
Yes
No
Friday, March 19th, 2010 AT 12:24 PM
  • Tiny
  • 90mazda
  • Member

I determined that cylinder 2 and 4 are not firing. Since I replaced the spark plugs, wires, coil, distributor cap, and rotor and the two cylinder have a spark at those two plug wires, do you have any suggestions?

Was this
answer
helpful?
Yes
No
Friday, March 19th, 2010 AT 12:54 PM
  • Tiny
  • KHLow2008
  • Expert
  • 41,976 posts

Get a compression test done to verify if they are within specs.

If compression is within specs, swap the injectors between the 2 good ones and retest if it is still # 2 and 4 that is misfiring.

Was this
answer
helpful?
Yes
No
Saturday, March 20th, 2010 AT 7:50 AM
  • Tiny
  • jtc
  • Member

I have exact problem, not hitting on 2nd and 4th cylinder. Have checked cam shaft--llifters, will check compresson in the morning. This is making me crazy. If I pull wire to second plug out of distributor I get alot of arcing from the wire that runs to the coil on fender of the truck. This is a mazda b2600i is there 2 fuses or 1 fuse for the injectors and where is it or they located?

Was this
answer
helpful?
Yes
No
Wednesday, July 14th, 2010 AT 10:57 PM
  • Tiny
  • KHLow2008
  • Expert
  • 41,976 posts

All four injectors are powered from the same source, via the FI main relay. Cylinder 1 and 4 works in tandem with a common ground at ECU. Cylinders 2 and 3 is another pair. That eliminates the possibility of power supply failure and you shoulc check the voltage at cylinder 2 and 4 to determine if it is a broken circuit.

Recheck the ground circuits between the engine and body, it could be insufficient and adding another might help.

Was this
answer
helpful?
Yes
No
Thursday, July 15th, 2010 AT 9:12 AM
  • Tiny
  • jtc
  • Member

I had a lifelong mazda man look at it today. He said computer is the problem.I hate to spend several hundred on something im not really needing.

Was this
answer
helpful?
Yes
No
Friday, July 16th, 2010 AT 9:41 PM
  • Tiny
  • KHLow2008
  • Expert
  • 41,976 posts

If it is the computer, then either you replace it or you try using a piggy back. Connect the 1 and 4 cylinder injector ground circuit to the computer. Likewise with 2 and 3.

For a cheaper alternative, you can try getting a reman.

Was this
answer
helpful?
Yes
No
Saturday, July 17th, 2010 AT 1:36 PM
  • Tiny
  • jtc
  • Member

What is the cheaper way or how do I piggyback my injectors?

Was this
answer
helpful?
Yes
No
Saturday, July 17th, 2010 AT 7:47 PM
  • Tiny
  • KHLow2008
  • Expert
  • 41,976 posts

Remanufactured computers are cheaper than new unit and locally you should be able to source them. Check with your local parts store for that.

After rechecking through the wiring diagram, I realised I made a mistake previously. For earlier models, the injectors would work in tandem, injector # 1 and # 4 are linked together whereas Injector # 2 and # 3 are a pair. This would rule out the computer as the culprit. If it is, you would not be able to start.

At the injectors, unplug all the connectors and test the Black/Yellow wire for battery voltage with ignition switch on.

If voltage is not available at #2 and #4, check for broken wires between the wires.

If battery voltage is available, test for continuity between the Light Green/Black wire of injector # 1 and # 4. If continuity is not found, you have a break in the wire and reconnecting them would work.

Likewise, perform same task with Light Green/Red wire between injector #2 and #3.

By the way have you tested and confirmed that the injectors are good?

Was this
answer
helpful?
Yes
No
Sunday, July 18th, 2010 AT 3:17 AM
  • Tiny
  • jtc
  • Member

Wire were tested at injectors. Are you saying its not the computer?Injectors do work when switched to another cyclinder. Not sure what you are telling me

Was this
answer
helpful?
Yes
No
Sunday, July 18th, 2010 AT 8:59 AM

Please login or register to post a reply.

Similar Questions