'73 Skipping Issue

Good morning,

My ‘73 has the basic inline 232. I just recently did a full tune-up in hopes that it would fix the skipping I’m getting in first and second year. The skipping continues and is pretty debilitating. Anybody got any ideas on what I should look at next????

 

Has the carburetor been rebuilt? Any car of that age needs it, if it has not been done.

Otherwise, unfortunately, that's a pretty vague symptom. But very nearly all such problems come from loss of fuel or spark, rather than something wrong inside the engine, so I would start there.

I would start from the fuel tank and check fuel delivery to the carburetor, and as mentioned above, rebuild the carburetor. Make sure you have no vacuum leaks around the carburetor base and between the manifold and the cylinder head - this is a common problem with the 232/258 (all inline sixes really). I suppose you replaced points/condenser/cap/rotor/plugs/wires, set the dwell and timing, set the idle speed and idle mixture. Check spark intensity at the coil wire. Check vacuum advance for correct operation. That will be a good start.

 

does the '73 use the prestolite BID distributor? if it does, that's where i'd start.

edit: perhaps it doesn't, as mr. reese mentions points & condenser.

 

Yep - '73 is points ignition. 1975 is the first year for the BID stuff.

 

"skipping?"

Under load, at high rpm, constant, during acceleration????
What are the circumstances and conditions?

What makes it betterer or worser?

 

My guess is that it's cutting out at high vacuum and high load. This suggests a big vacuum leak to me, making the mixture too lean under load. Runs ok at idle, under no load (revving but not driving) and at cruise ...

 

Sounds about right to me, with no other data to go on. Also your advice about checking vacuum advance operation...

 

Also, define "full tune-up". Just what did you do and what parts were replaced?

 

Thanks for the input. The plugs/were were all replaced..Idles just fine...To answer PeteL's question it worsens quite noticably in 2nd and 3rd gear as I accelerate...Does this additional info sound like a vacuum issue???

 

Vacuum leaks tend to show more under load, like popping or stalling as you try to accelerate from a low cruise speed. Keeping in a lower gear may overcome it somewhat. Possibly some other cause of fuel starvation, but that is also worse under load, like climbing a long hill - in any gear.

Originally you cited the skipping in first and second, now you say second and third???

Define "skipping" - I think of a skip as a rythmic beat or steady repetition. Or do you mean random roughness, or drastic power loss?

If it is strictly RPM related, I'd suspect the points, timing, or vacuum/centrifigual advance functioning.

Did your "full tune up" include those? You only mention new plugs.

 

Take a video of what is going on when you drive it, upload it to youtube and post the link here.

in the automotive world we dont use the term "skipping" the term you're probably looking for is "misfire" or "missing"

 

The tune up ONLY included new plug wires and new plugs. The best way I can describe it then is "missing" (there is no "pop" per se as it "misses"). I know that the former owner has a SPE-2358 filter leading to the carburetor that I have just replaced (I had an issue at idle as fuel was starved) so idling is now fine so I feel fairly confident that fuel is not the issue... the filter is a CLEARVIEW FUEL FILTER ELEMENT. All I know that I suffer a big "miss" in all gears as I accelerate.....does this additional info help?

 

Yes on the above...................including the Condenser , Cap & Rotor.........sometimes a coil...............check the primary wiring to and from the coil and ground.......

 

James, I would go ahead and do a full tuneup, with points and condenser, new cap and rotor, new air filter element, set the timing and dwell, set the idle mixture and idle speed.

Speculating about this will only take you so far. You need to replace all the consumable parts of the fuel and ignition systems (fluids, filters, ignition parts) to eliminate issues that might be coming from normal wear and tear. Plus if this Jeep is new to you, it's important to do all this maintenance since you don't know what was done and when under the previous owner. I would also replace the belts and all hoses of a new-old car.

Once you have done all the maintenance, stop guessing and be systematic about testing the fuel and ignition systems. Do you have the TSM for your year? The TSM will be very helpful, and typically contains flow charts and procedures to diagnose problems like this. You already have had inadequate fuel delivery - test the output of the fuel pump. If the ignition coil is suspect, pull the coil wire from the cap and test the spark intensity to the engine block. It should be a blue-white spark that can jump about a 1/4" gap. Following that, I think the best test is to simply replace it with a known good coil. If you can't borrow one from another car, or buy a couple at the junkyard, just buy a new one. If that's not the problem, you need a spare coil in a Jeep anyway. They do fail suddenly, and can leave you stranded. BTDT.

PSA - Which Manual Should I Buy?

 

Thank you timgr!

 

Well - that's not hardly "a full tune up" as described originally.

Start with getting the basics into spec, or you are chasing your tail.

 

I know I know...it was more a 1/2 $#@ tune up...I got it in shop getting the balance of what should have been done to it done..They are doing rotor/cap etc..I will update what the "fix" was in their estimation..

 

Final update. My guy replaced the points/coil/condenser/cap and rotor. Sh runs smooth in all gears now..I think the "1/2 tune up" was issue all along....thanks again for the unput...

 

"Unput"

Love it! I'm so stealing that…


PS - Do a tune up once a year. Your jeep will thank you.