I have a 93 Accord LX 5spd, and lately when you would start it first thing when it is cold out it would fire then stall. Then after you would start it, rev it up to keep it running, it would be ok but as you drive the tach jumps around. It is not in relation to the engine speed, as it does not jump the 1000 RPM as fast as the tach shows.

I am just wondering if there is a good starting place to look. I searched and most were issues with the idle jumping around (it does this too, but not related to this issue). I have also found ignition switch issues, have tried wiggling the ignition switch, and it the tach would fluctuate a couple times but then not respond to the key wiggle anymore. Still jumped around a bit though on its own.

93 Accord LX, 5 spd, 350K miles

 

The tach signal comes from your ignitor (inside the distributor). Might be the early signs of a failing ignitor? Or maybe some loose/dirty/corroded connections in the wiring harness. Check the harness plugs at the distributor. If no luck there, I'd have to defer to someone with a 1993 wiring drawing for other harness plugs in that circuit. Seems to me there's a great big plug near the left-front shock tower that's involved but I'm not sure about that.

 

I'd pull off top of distributor and run finger or Q-tip in there to see if there's oil in there.
My '93 started getting misfires, major loss of power, etc a couple thousand miles before it left my son stranded on side of road.

Mine started after I switched to syntheitc oil, btw.

 

My experience is that oil in distributor only becomes a problem when it doesn't drain adequately, but a large leak could cause issues. The oil could cause spark to short to ground, particularly once arcing establishes a carbon path to ground.

I have seen rpm fluctuations due to spark plugs, wires, and ignition coil. If spark plugs and wires have any age on them, it might be best to start w/ them.

good luck

 

My suggestion of the ignitor is from thinking(?) that the actual RPM doesn't fluctuate at all. In other words, the tach jumping around is completely bogus.

If the engine actually surges, then I'd suspect the things that Tex suggests. For that matter, check all of it just to rule it out anyway.

 

Thank you everybody. I had to replace the distributor maybe 3 months ago, it died on the highway. The JY one leaked oil pretty bad internally, so I swapped the modules over to the old dizzy housing. No more oil leaks, and the housing was dry when I put the modules in. I did just replace the plugs (Autolite Copper like always), cap, and rotor. Wires aren't that old - replaced them when I did valve cover gasket and such last spring.

Maybe I'll just get a reman unit and go with it. They are getting impossible to find in the JY anymore, those that the dizzy is still there they are gutted. I think someone has been walking thru and pocketing all the modules...

 

Would there.be ant way other than with an oscilloscope to measure the signal at the dizzy by back feeding the connector? I only have a dvom, which has a freq counter but it is only for 5v Max signals... maybe a dwell meter?

 

Got a dwell meter? Most of them also incorporate a tachometer. Sure, use that, but I don't know the pinout for which wire to hook up to your tach.

From one dinosaur to another I guess we're old enough to know what a dwell meter is...?

 

Lol.. I'm "only" 36, but I do remember helping my father tune up a few points setups.

Well, I am updating this as a possible solution. I risked it, payed the $150 for a reman dizzy, and as of now it is looking good. We'll find out in the morning when my GF has to drive home from work whether it was a success or not, as it will be colder (acted up more when cold ambient temps). I normally don't like making diags without proof as to the failed item, but I'm on vacation this week, it's gonna be cold and rainy, and I didn't feel like working on a car under a carport all week. Hoping this educated guess was right!

Thanks again.