Hi, I still drive the '88 Wrangler I bought in Oct '87. She has 171,000 miles. Recently I had a rebuilt motor,transmission, etc… installed. I had the existing carb rebuilt. This summer , while driving at any speed, the tach would drop to zero and the whole car would lurch. Sometimes so violently my seatbelt would lock up. After a couple miles of lurching it would backfire several times. (these symptoms have become known as belching, vomiting and farting) This is very scary. Several different mechanics have posited several different possible causes.
Here’s the really bizare issue - now that the weather is cold, the issue has substantially (not completely) diminished. On a warm day in the 50’s it will act up again. I live in Watkins Glen, NY. Yes, I’m a (Indy Car) racing fan.
Sounds like you have a failing COIL…or Distributor cap…(Leaning more on the coil bec of the tach clue in addition to the others plus its more common)…Either can be affected in a bad way when they have an issue…The HEAT makes say a microscopic crack…turn into a microscopic Cleft…and thus allow voltage to leak to ground…and not to your plug wires and plugs…to run your engine… Happens ALL THE TIME… Now that it is cooler out, the issue is HIDING until the heat wakes it back up.
I would replace the Distributor Cap and Rotor First (cheapest) and see what you get…if not that…then replace the coil… Its most likely either (bet its the coil ;)… ) one and if you replace both at the same time you wont know which fixed it…Not that you care but, you wouldn’t know. Both sets of parts for your vehicle are CHEAP…and you can do them yourself… Oh yeah…the wires can also do this when they leak voltage too certainly but I suspect the others and in that order…
Thank you very much, Ladies! The Jeep is at the shop now getting some paint. I’ll let the mechanic know your thoughts and see if he’ll take the Jeep for a spin after it’s been inside all night.
Well, two months after posting my question I can tell you the problem is not with the coil or cap and rotor. It is not the plug wires. Not the ignition box. I also had the EGR valve changed and the fuel pump and filter. Any other ideas?
Speaking of Jeeps.
Speaking of racing…and very off topic …
Many Jeeps and others will be in Moab Utah next week for a rock crawling rally.
Youall should go , it IS a spectator sport.
To see my local bros ( not those high dollar sponsored beasts ) visit www.jeepswest.com and view their videos.
My second counterman, Chris, will be in Moab with his 78 CJ7.
Your symmptoms are textbook carb symptoms, specifically meaning you’re running too rich or having problems metering. The backfiring is unburned fuel blowing out the exhaust, and it improves during cold weather because you need a richer mix in cold weather anyway.
Since you’ve installed a rebuilt carb, and assuming the carb was totally rebuilt, I’d recommend going back over the adjustment process step by step, also making sure that the temperature control (the choke control) is working properly. If you had the carb installed and didn’t do it yourself, bring it back and let them go back over the adjustment process.
You say you had the ignition module replaced?..comon failure item back then…next would be the pick up in the distributor. Ignition loss causes the tach to go to Zero. Ignition switches too…Pick up’s more likely to temp sensitive