I've had my 85 CJ 258 T5 for about 4 months now. Within the past three weeks, I've noticed the engine start to misfire which results in the jeep bucking like a bronco at speed.
I feel the power loss and then it kicks back in. It is more noticeable at a higher rpm and speed. It does not happen at a common interval.
My initial thought is timing, but I'm picking up some new items this weekend to be sure:
If it is timing, I'm probably going to find a shop because the last time I played with timing was 20 years ago on a 54 Willys.
So the question is:
1. Is timing the most likely culprit? How long does the timing hold?
2. I understand that I shouldn't get new wires unless I explicitly know they are bad. Is this correct?
3. What kind of cost am I looking at to fix/set timing?
4. I live in an extremely humid environment. Is it good practice to spray WD40 into the distributor to keep water out?
Thanks in advance. I'm going to go fill out my profile now to try and save some questions.
Buying a timing gun at some cheap shop should be less than 50 bucks....
Remove the vacumn plug from the distributor plug it...
Read the internet for the setting it should be at...
Read the instructions from the timing gun... hook up and read the numbers...
Loosen one bolt, twist the distributor to get the setting right...
Tighten bolt...
Done...
Now it sounds like to me either a timing or accelerator pump... so Carb rebuild or timing... Usually timing doesn't change but you should do plugs, wires, cap every so often...
Buy a $23 carb rebuild kit... and follow the directions... take pics on disassembly put it back in the reverse order... all you need is a couple wrenches and a screwdriver.
Buying a timing gun at some cheap shop should be less than 50 bucks....
Remove the vacumn plug from the distributor plug it...
Read the internet for the setting it should be at...
Read the instructions from the timing gun... hook up and read the numbers...
Loosen one bolt, twist the distributor to get the setting right...
Tighten bolt...
Done...
Now it sounds like to me either a timing or accelerator pump... so Carb rebuild or timing... Usually timing doesn't change but you should do plugs, wires, cap every so often...
Buy a $23 carb rebuild kit... and follow the directions... take pics on disassembly put it back in the reverse order... all you need is a couple wrenches and a screwdriver.
If it starts and runs OK at idle and lower RPMs, then it's probably not timing.
Does it misfire when you rev to higher RPMs while parked in the driveway, or does it only do it under load?
Is this engine Nuttered?
Have you checked the condition of the plugs?
Have you checked for vacuum leaks?
Any recent modifications to the engine?
What carb and when was it last rebuilt?
My first guess is a fuel delivery problem, based on the limited information you've provided.
Does it misfire when you rev to higher RPMs while parked in the driveway, or does it only do it under load?
It is barely noticeable at idle. When accelerating it is the most notable (which also struck me as fuel related hence the filter for initial test). It seems the fuel pump is ~20 bucks. Worth it to just replace it?
Is this engine Nuttered?
No
Have you checked the condition of the plugs?
I have not, but was going to replace anyways this weekend with the aforementioned autolites per other threads I've read. When I pull them, I'd like to see condition as I've had a little white smoke, assuming steam, in warm up.
Have you checked for vacuum leaks?
I have not.
Any recent modifications to the engine?
When I purchased the CJ, it was not running. It had initial work to get it running which involved removal of a fuel regulator and some extra unknown nonsense from PO. The work was done by a local Jeep God Steve from Steve's 4x4 in New Orleans. These were the only engine/fuel modifications. He reported that the plugs and rest looked good at the time. These mods were done months and months ago.
What carb and when was it last rebuilt?
OEM 2bbl. I will upgrade when I have time but don't have the extra funds kicking around right now. Was going to get some carb cleaner and I've also seen the carb tuneup kit, as mentioned above, recommended.
If it starts and runs OK at idle and lower RPMs, then it's probably not timing.
Does it misfire when you rev to higher RPMs while parked in the driveway, or does it only do it under load?
Is this engine Nuttered?
Have you checked the condition of the plugs?
Have you checked for vacuum leaks?
Any recent modifications to the engine?
What carb and when was it last rebuilt?
My first guess is a fuel delivery problem, based on the limited information you've provided.
If the troublesome computerized feedback system is still in place (not Nuttered), then your problem could be one of about a dozen things.
Before you just throw parts at it, let's try to do some actual diagnosis, first.
Start by pulling all the plugs. Do they all look the same, or does one or more look different? What is their overall appearance...dark, light, tan-ish? Do any of them appear fouled (wet)? Post close-up pics of the plugs, and we'll help you read them.
If the troublesome computerized feedback system is still in place (not Nuttered), then your problem could be one of about a dozen things.
Before you just throw parts at it, let's try to do some actual diagnosis, first.
Start by pulling all the plugs. Do they all look the same, or does one or more look different? What is their overall appearance...dark, light, tan-ish? Do any of them appear fouled (wet)? Post close-up pics of the plugs, and we'll help you read them.
Will do this weekend. I'm afraid that one may look steam cleaned, hence white steam in exhaust and a slightly gassy smell which I've been experiencing. This has been occurring before the current issue.
Yes, if it is still computer controlled it could be a huge number of things.
I do no see that you mention white smoke... another bit of the puzzle...
Check the plugs... as Matt suggests... and yes... buying parts before you know what the issue is... will cost more than asking questions and figuring out whats wrong...
Doesn't sound to tough but the plugs might give us a clue...
I'm still in the rebuild the carb group though haha... maybe vacuum issue....
Gas smell is usually to do with a charcoal canister or EGR which could also cause what you are experiencing.
Replying because screw those people who put help threads with no conclusion.
Because of life stuff, I was not able to work on it. So, I dropped it with my local Jeep Guru Steve at Steve's 4x4.
Just got the call. He was driving the jeep, experienced the same issue. He noticed black smoke when changing gears (T5 standard).
Rebuilt the carb, replaced the sparkplugs. And that was it. 1 day turnaround for 150 bucks.
Thanks to all regarding the help here. I look forward to reading more of your insight on these amazing machines.
Time to go pick her up. If he has the old plugs still, I will take pics as requested. Also, I had feared that I had a head gasket issue but that is not the case, which makes me very happy.
Another good tip for the future. If the jeep is not your DD, or even if it is, find a station that carries non-ethanol fuel in your area. http://www.pure-gas.org/
Get a small 1-2.5 gallon container and leave it full in the jeep for the times you can't make it to the station without going empty. It should make your carb much happier over the long run and cause less issues overall for you. Ethanol won't do much in small batches, but over time, as especially if you let it sit, it will gunk up a carb pretty good.
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