Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: chomper on December 30, 2005, 08:32:28 PM

Title: I wish I was a mechanic! Help needed..
Post by: chomper on December 30, 2005, 08:32:28 PM: Evening All. My YJ Laredo (1987, 4.2L, 6Cyl) has been playing up for a while. Been running on less than 6 cylinders and making some funny noises. Figured that maybe the plugs needed changing so I changed the plugs, leads, rotor and Dizzy cap. I noticed that the plugs that came out were considerably shorter than the ones supplied by Lighthouse.

Started her up and she sounded a lot more healthy. Took her for a test drive and the usual happened. After about a mile or so (just enough time to warm up a bit) it starts to feel like someone is slowly pulling the handbrake on.

I was on an A road doing 80Kmh and she gradually slowed (flat road, by the way) to 60Kmh and wouldn't really go above that.

It's a very low mileage Jeep for its' age, having only done 18k miles in 18 years! Bubba assures me this is genuine as he has verified this through his discussions with the chap i bought it off.

Anyone got any thoughts, coz at the mo i'm scared to come out and play. I know the basics of how an engine works, have a good toolkit, am pretty handy, but I'm certainly no mechanic so any suggestions gratefully received.

If no-one has a clue what it might be, could someone suggest a good Midlands or South West garage to take 'er to.

Cheers
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Post by: Anonymous on December 30, 2005, 08:38:31 PM: Does it only happen after it starts to warm up?
if it does it sounds like a fueling problem (over fueling)
if so it doesnt have an auto choke by any chance? (could be duff)
what colour are the plugs if you take them out (clear/grey or black/sooty)?
do you know anyone who you could borrow a coil off in case that it on its way out?
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Post by: trent on December 30, 2005, 09:15:37 PM: chomper,
Do you have a catalytic converter?
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Post by: Anonymous on December 30, 2005, 09:26:09 PM: Reckon whatever the short term problem is you need to use it a quite a bit to loosen it up....
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Post by: greggmo on December 30, 2005, 09:31:52 PM: hey mate, you might just have some muck in the carb. it might pay to take it off and give it a good clean out mate. dont forget your little splosh on the last outing to ribbo. . other than that it might be a breather.
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Post by: Mike Pavelin on December 31, 2005, 10:12:35 AM: I had a 258 YJ do a similar thing, Started up ok, then started to misfire, lose power as it warmed up. Took a while to find, rebuilt carb, checked all usual fuel and ignition suspects. Eventually turned out to be the AMC electronic ignition module breaking down as it warmed up. Hooked the output to the coil to a scope and you could watch the signal start out healthy, and start to become weak and erratic as it got hot.
This is a not uncommon problem and replacements are available from Lighthouse, Mildenhall Motors etc. If you can't find anything else, get a proper auto electrician or diagnostic centre with access to a diagnostic scope to have a look at this as a potential cause.
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Post by: chomper on December 31, 2005, 11:02:35 AM: Quote
if so it doesnt have an auto choke by any chance? (could be duff)
what colour are the plugs if you take them out (clear/grey or black/sooty)?

Yeah it does have an auto choke. Not sure how to tell if it's duff but i can see where you're coming from. The plugs were fairly black when they came out but they were definately the incorrect onew.

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hey mate, you might just have some muck in the carb. it might pay to take it off and give it a good clean out mate. dont forget your little splosh on the last outing to ribbo. . other than that it might be a breather.

I'll have a go at that tomorrow, thanks .

If that doesn't work, I'll whip it down to a local diagnostic place.

I'll let you know how I get on. Cheers Guys.
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Post by: Anonymous on December 31, 2005, 11:43:34 AM: disconnect the auto choke and give it a whirl, some you have to take a lever off some you have to part strip the carb, see if you can wedge the choke before stripping it just to see.(or look if it hasn't moved position from cold to hot)
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Post by: Mike Pavelin on December 31, 2005, 11:45:04 AM: Re. choke, run it up till its hot with the air cleaner off. See if the choke flap opens up fully. It should be shut when cold, and gradually open as the jeep warms up, but you may have to blip the throttle a couple of times during warmup to allow the ratchet mechanism to release, as the auto choke operates the fast idle as well.
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Post by: Bubba on December 31, 2005, 11:28:13 PM: tis carb problem for sure take the top off the float bowl for crud pull the jets and make sure not blocked could be choke but my moneys on crud i never had a module go yet and if by a long one it turns out to be that feck lighthouse or anybody get ya ass down the scrappys and look for any v6 granada or scorpio same module same plugs and part no
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Post by: Bubba on December 31, 2005, 11:49:05 PM: or another thing pluglead/s breaking down silicon leades are shit and not to be trusted throw them at your binman ang get some proper ones
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Post by: chomper on January 01, 2006, 10:13:54 AM: Gonna have a crack at it today! Carb and choke do seem most likely candidates. Especially as Greggmo points out, she was up to her ears in shit at Ribbo!

I'll let you know how I get on. Thanks for all the help guys.
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Post by: chomper on January 01, 2006, 02:24:01 PM: OK I cleaned the carb and there was a bit of shit in the float chamber. gave it a good clean and put it all back together. Took it for a spin and for about 3 miles it ran fine. Then I stopped to talk to a cyclist and when I set off again I had the old problem.

There is abit of a ticking/knocking noise every now and then which makes me think it's missing, but it's not obvious to a numb nuts like me.

I had a look at the choke while I took the carb apart and it was very black. Not sure if this is normal. Cleaned it all and put it back. I'm tearing my hair out now because I so want to get her sorted.

Do you think I should take it to a workshop and get someone to have a look?
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Post by: tervueren on January 01, 2006, 03:32:11 PM: If there was crap in the bowl then chances are it's elsewhere as well, did you remove and clean the jets ??
Title: History
Post by: Anonymous on January 27, 2006, 09:08:01 PM: I believe that this is an event that should be noted in the history books.
Title: Re: History
Post by: tervueren on January 27, 2006, 09:23:48 PM: Quote from: "Joe70890"
I believe that this is an event that should be noted in the history books.

:smt017
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Post by: isle of man on January 27, 2006, 09:24:54 PM: does it have a condenser????? just a different chain of thought.

peter henry
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Post by: alcoholicmaggot on January 27, 2006, 09:25:00 PM: looks like an gremlin automatic poster :?
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Post by: chrisjones on January 27, 2006, 09:52:02 PM: Or Stew under an assumed name.
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Post by: Anonymous on January 27, 2006, 09:53:26 PM: Tis not Stew.......he doesnt need a pseudonym to be obscure!!! :?

Just another bot....Birty, kick the arse out!!!!
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Post by: Bubba on January 27, 2006, 09:58:39 PM: yeah fuck off wanker
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Post by: trent on January 27, 2006, 10:00:38 PM: birty please get rid of this mug!!!!!!!
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Post by: trent on January 27, 2006, 10:02:56 PM: That'll teach me to watch big brother (dare i admit it? :? ) while i'm slowly writing my post :lol:
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Post by: Anonymous on January 27, 2006, 10:09:25 PM: Uh did someone say obscure posts.........
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Post by: birty on January 28, 2006, 10:13:12 PM: Quote from: "trent"
birty please get rid of this mug!!!!!!!

Done.
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Post by: trent on January 29, 2006, 12:21:27 AM: :smt023
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Post by: Anonymous on January 29, 2006, 08:32:22 AM: And the difference in this thread is what ????
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Post by: Anonymous on January 29, 2006, 12:51:47 PM: mmm insanity