Jimny is being choked-what could the issue be?

Hello,

I'm a new member from Alberta, Canada. Jimnys are quite uncommon here, so you'll forgive if this is a bit of a dumb question.

My 1992 Jimny here has an annoying issue. When idling or crawling around a parking lot, it seems fine. But when you demand any sort of power, it lugs like you just slammed it into too high of a gear. But in neutral and at low speed, you can rev it to the moon as per usual. Something is choking it or holding it back. The only time is approaches normal function is in the tiniest little "sweet spot" of throttle, where it will twitch and jerk and attempt to pull as it should..

Initially I assumed the crusty old fuel filter that the previous owner never changed was the culprit. But I changed it, ran some fuel line flush through, and nothing really changed. I don't suspect an electrical issue, because the motor is ticking over fine, and I don't suspect some of the more outlandish ideas I was suggested by people elsewhere, like the timing belt or fuel pump. The odd behaviour of the throttle and the "choking" just screams "fuel issue" to me.

I was thinking of swapping the fuel regulator next, but I was hoping to get some advice/opinions elsewhere here before spending even more cash on this car (since nobody in the country carries Jimny parts). Any feedback would be appreciated. I'm starting to go a bit nuts here. It has the 660 Turbo, with only 60,000km on it, it shouldn't be failing this hard this early.

Hi Tok, Without sounding vague the issue could be multiple things. The Jim looks very tidy, so I'm assuming the motor has been equally cared for?

The things I'd be checking when hunting down engine hesitance/sluggishness are:

- Regular good quality oil changes?
- Ignition/good spark. Check the condition of your plugs and leads (measure the resistance of your leads) loads of info online about this.
- Timing, distributor cap/ coil pack. I'm not familiar with the early Jim engine but I suspect it had a distributor cap? if so check and replace the contacts.
- Fuel delivery, check the condition of your injectors/Carburettor. Might be worth buying some fuel additive and giving the car a 'Italian tune up' on the highway.
- Throttle body, have a quick look at you're throttle body and ensure the butterfly valve isn't chocked/gummed up.
- Vacuum leaks. This is a really common one! Any sort of poor seal around the engine air intake, Modern cars often suffer from vacuum leaks post Air intake sensors which messes up the cars fuel/air mixture is out of sync. Vacuum leaks could also be a poor seal around the oil Dipstick so check the little O-Ring on the plunger.

- I don't think a '92 Jim will have a catalytic converter? but in the rare instance that it did.. Again get a food fuel system cleaning additive and drive the car like you stole it.

My old sports car had a very similar problem, It turned out to be Ignition (spark p, leads & coil pack) along with several bad vacuum leaks. I replaced all of the rubber vacuum hoses for new and replaced the ignition gear, the engine had a new lease of life.
:whistle:

I agree with the vacuum idea, the fact that it is bogged under load suggests that the timing is not advancing which means a vacuum leak. Probably. We in the uk didn't get the 660 turbo so knowledge of specific issues is somewhat limited.

Hello and welcome. Very tidy Jimny, looks well maintained.

Plenty of good suggestions above, but reading your description my mind kept going to plugs and or weak coil pack as a possible cause also. Like Dagzook I had an old classic car that had this problem, ultimately caused by the coil / plugs / HT leads. I also don't known anything about the 660 turbo engine unfortunately (is it fuel injection or carburettor?), but with a carburettor the same could occur if the accelerator pump had failed, an enrichment device under on acceleration demand. Just my old uninformed mind throwing out some suggestions.
But keep it simple, and if you don't know the service history of any components that's the place to start, a good service and check of timing etc.
May not be the cause, but it eliminates some items and a service is not wasted cash.
Good luck
Mike

A BIGJimny welcome to you from the UK, Tokguy

Im with the possible vacuum issues everyone else has mentioned, and Simike mentioned coil-packs as being one of the usual suspects.
Also, check and/or clean any in-line fuel filters for debris

Good luck, and let us know how if any of the suggestions here reveal anything

It is fuel-injected.

I suppose that I’ll have to check the vacuum lines and electrics. I’m hoping it’s nothing as serious as the injectors needing a swap. Hopefully I can get it running and have good news for everyone who responded.