Intermittent stumbling

[joebeets]

My engine starts rapidly cutting out and in after 20 mins of driving. I lurch down the road with steady throttle but tach oscillating regularly between approx. 2000 and 2500, on a 1 second cycle.

This will go on for several seconds, then it might run perfectly smooth for 100 yards, then resume. Putting it in neutral makes no difference. Eventually it starts to stumble and I have to pull over. I don't have to be cruising; first appearance was when it died at a red light.

But If I shut off the engine, wait a couple minutes and restart it goes away.
I've already replaced the igniter/coil and ignition wires. The cap and rotor are recent, and I swapped the ECU. No dice.

I'm thinking radio condenser next. It's unlikely, I know, but it's the last ignition component unchanged. If that's not it, I'll have to start looking at solenoid valve vacuum leaks. It doesn't seem like a fuel supply problem.

Any other suggestions?

TIA,
Joe

[shepherd79]

check the vacuum lines. if you have a crack somewhere in line, it will do that.
the other thing, you may want to start looking to rebuild the carb or replace it with rebuild one.

[TINBOAT]

Sounds like a plugging fuel filter...easy to check and replace.

[joebeets]

Thanks all--it was the radio noise condenser. I almost was ready to rebuild the carb--if the idle mix solenoid tested OK--but decided to spend $8 first in hopes of avoiding all that effort.

I did notice there's a warning in the Helm manual saying the car won't run without this component, but it's not mentioned in their troubleshooting grid under stalling.

[joebeets]

The quest continues...

[Blkblurr]

Does it happen when the engine is cold only? If so it could be your fast idle solenoid.

[Bryan Smith]

Okay ive got the exact same problem... joe, if you WOT does the stumble go away? Mine does, and if the engine is cold, it doesnt stumble "that much" now this stumbling JUST started today after I had the front wheels off the ground for a split second doing 90 on a backroad. Wee that was fun.

[Bryan Smith]

hrm okay sorry for the whoring. I think i just fixed mine. I cut the wiring harness from one of my dead headlight motors, and the wires were exposed, touching the metal on the body, and i believe was the culprit. I taped it off, and so far so good. hrm...

[Strugglebucket]

You might want to check your timing belt for missing teeth.

[Bryan Smith]

Damn the wiring wasnt my issue. It still stumbles. I havent checked the plugs or what not. But why would the engine start stumbling after I bottom out the front suspension?

[joebeets]

It was the alternator. Or I should say the voltage regulator, sending out an intermittent over-voltage that would disable the ignition.

Wish I could say I figured it out, but the realization came only after I swapped the alt under warranty due to an unrelated issue (no voltage at the terminal which extinguishes the warning light on the dash). And this only because I got a notice to report for emissions testing, and they won't test if any dash lights are on.

I should have guessed when, after replacing what I thought was the last of my ignition components, the problem improved but didn't go away, proving I still had an ignition probem somewhere, but who thinks of the alt as part of the ignition?

Worse, I had an identical problem, not intermittent, in my old Alliance. Towed to dealer, who said I needed a new computer, and when I produced a $20 junkyard computer and the problem didn't change, he claimed that one had the same problem! Towed it home and eventually made the bad voltage regulator discovery on my own.

Hopefully I'll learn this time.

[joebeets]

Wasn't the alternator. The elusive problem continues, and hope of a fix is fading. We'll see if we can use it as a go-to-work car, and use my other car for long trips. Otherwise I'll unload it as "needs work".

As much as I feel Hondas, and Asian cars generally, represent superior engineering, I'll never understand their decision to produce such an unfixablly complex carbed car as part of a marketing strategy to sell a few "step-up" LXis.

Oh well, at least now I have an excuse to buy something else

[joebeets]

Seems it was the fuel pump. Just as I was Googling around trying to find a rebuilt carb, I came across this site which suggested it as a cause. Obvious in retrospect. BTW I recommend the OEM complete assembly at $100 vs. the AutoZone pump only for $65, which requires a lot of work.

[POS carb]

man i hope that fixed it for you I was going to say either the coil/ignitor are going or you have vapor lock.
I have the auto zone $30 one

[A20A1]

Have you checked the:

Booster venturies ? https://www.3geez.com/showthread.php?t=8972

Stator allignment ? https://www.3geez.com/showthread.php?t=22648

Ground Wire to the thermostat housing or other ground wires ?

[brian4g63]

Open hood, remove airbox above carb/shit holding it on, with all vac's exposed look to the drivers side. Theres a white capped denso thing and a vacuum coming off it going towards the drivers side. Is there a crack? If there is push the vaccum line on farther and duck tape the shit outta it. It got warn from the airbox tube rubbing agaisnt it.

[joebeets]

Thanks, but it was definitely the fuel pump. Completely fixed now. On to the next problem--corroded power steering pipes.