[JacintasHot]

Fellas,
I have a nagging problem with my 1993 Mazda B2200 pickup. It's powered by the 2.2 L feedback carbureted engine attached to a 5 speed manual. While accelerating normally, the engine "hiccups" halfway through the 1st 4 forward gears. It'll do it in 5th if you're cruising @60 and let up on the gas ever so slightly to bring it down to 55. It's uber-annoying-nobody can seem to figure it out. I'm thinking a sensor or a solenoid is the culprit. I need to know which one it is exactly so I can get a replacement.

Thanks,
Chuck

[John V.]

Have you seen this?:

http://www.mazdatruckin.com/B2200/OEMCarb.html

Never had a Mazda, but have had a couple "mystery" driveability issues that no Check Engine Light will help you find.

Some years back, would experience engine "missing" only when moving. Idled fine, rev'd fine in the driveway, came to realize it would miss especially over a bump. One day, went over a rough RR crossing and it sputtered.

When I got home, I started moving wires around underhood. When I moved the "right" wire, it sputtered. Unwrapped the wring, discovered a connector that was melting. The wiring was in the fuel pump circuit. When jostled, the fuel pump would momentarily quit. Replaced the connector, no more missing.

Couple weeks ago, my '99 Sunfire started intermittently stalling at idle, or would run rough as I got off the clutch in 1st. Turned out a 4" long vac hose between the Manifold Absolute Pressure (MAP) sensor and the throttle body had dried out and split.

A $1 piece of vac hose later and the problem was fixed.

Similar problem several years ago with a PCV valve vac hose. Hose had a hole in it, major vac leak. Engine running rough. Spotted the hole, put my finger over it, engine smoothed right out. Replaced hose, no more rough idle.

Check all of your vac hoses for vac leaks. Move wires around to see if you get a sputter.

Clean the carb and diagnose per the link.

Also, see if maybe there is wear in the carb linkage. Saw one suggestion that some sort of carb linkage shaft gets worn, might cause a "dead" spot at the same point as you accelerate thru each gear. Sounded like you could remove an e-clip and rotate the shaft around to eliminate the problem. Made no sense to me since I can't look at the linkage, but perhaps will make sense as you look at it.

[Lightfoot]

You didn't mention whether the Check Engine light has come on.
Even if it hasn't, there may be a pending code in the ECM that could possibly help.

Your Mazda should have the old OBD-I test terminal under the dash. If you jump the two pins that are next to each other, on one end, it will display any trouble codes by causing the engine light to flash, like morse code. One blink followed by two blinks = 12 and so on.
They usually repeat each stored code three times, then go through them again. You have to hold the jumper wire or paper clip, in the test terminal the whole time.

[folsombird]

Have the spark plug wires ever been changed? I had the exact same problem on an old 626 I used to have.

[JacintasHot]

Thanks to all for the input. I'll be checking into things this week. I'll keep ya posted.

Chuck