DracoSedentis Posted February 21, 2018 Posted February 21, 2018 So recently I've taken my 86 Comanche to a new shop. The other shop I took it to did a lot of good work but failed to figure out why it has a rough idle that causes it to stall in neutral fairly often. They've had several opportunities to do this at my request and failed at that. I took it to this other shop that has done work on my POS liberty and have always done a good job. They called me back within 2 hours and told me that it failed emissions (utah) and they informed me they found a pretty major vacuum leak in the throttle body shaft. My question: What is the throttle body shaft and where is it located? Am I just miss-identifying it? I've cleaned the throttle body on my other jeep (99 wrangler) and am familiar with most engine work. However, I've never worked with a "throttle body shaft". Some clarification would be great. As well as where I might find one.
dasbulliwagen Posted February 21, 2018 Posted February 21, 2018 It is the pivot point for the throttle valve (blade, Butterfly). The shaft runs front one side to the other. On one side the throttle arm is attached which is then pulled by your throttle cable running from the accelerator pedal. The pivot point can wear out over time cause excessive play and thus a vacuum leak, causing too much air in at idle, and a possible lean condition which could cause a stall at idle if too much.
Jeep Driver Posted February 21, 2018 Posted February 21, 2018 You might have a hard time finding a 2.5 TBI throttle body. IOWs it's not going to fall into your lap. http://www.fuelinjector.citymaker.com/web_page.html Call these people and see if they still have one NOS. Call here, Mr Complete Jeep, http://www.creepersjeepers.com/ I'm almost certain he'll have a used one.
FrankTheDog Posted February 22, 2018 Posted February 22, 2018 1986-1990 throttle bodies are interchangeable. Shouldn’t be to hard to find one. I have one off a 1988 that worked good when it was run last. How many miles does your MJ have? Where are you located?
DracoSedentis Posted February 22, 2018 Author Posted February 22, 2018 Just now, FrankTheDog said: 1986-1990 throttle bodies are interchangeable. Shouldn’t be to hard to find one. I have one off a 1988 that worked good when it was run last. How many miles does your MJ have? Where are you located? MJ has ~147k miles on it. 5 speed on the floor. In fantastic condition other than this issue and a few expected issues for a 30+yr old vehicle. And I'm in Utah.
Jeep Driver Posted February 22, 2018 Posted February 22, 2018 22 minutes ago, FrankTheDog said: . Shouldn’t be to hard to find one. Since 2011 there have been 4 2.5s that have been in the JYs local to me, none now that I know of. Nothing on ebay. They are hard to find, most TBI era parts are hard to find. This is a NOS that I found a few years ago.
DracoSedentis Posted February 22, 2018 Author Posted February 22, 2018 So my understanding is that these are going to be something along the lines of a needle in a haystack? Good thing is that here in Utah there are a plethora of jeeps both old and new on the road and in scrap yards. Maybe I'll be able to find one somewhere. Are there any other manufacturers I should be aware of that are or would be interchangeable as well?
Jeep Driver Posted February 22, 2018 Posted February 22, 2018 They are MJ and XJ specific, nothing else.
DracoSedentis Posted February 22, 2018 Author Posted February 22, 2018 3 minutes ago, Jeep Driver said: They are MJ and XJ specific, nothing else. Just my luck. LOL Looks like I'll be either trying to find a used one or try finding a rebuild kit.
carnuck Posted February 23, 2018 Posted February 23, 2018 The shaft bushing wears out, but if it’s fixed with a bushing kit, it’ll be fine. I have knurled them in the past and used nylon tee bushings well lubed to fix them and carbs. Sent from my iPhone using Tapatalk
FrankTheDog Posted February 26, 2018 Posted February 26, 2018 On 2/21/2018 at 9:15 PM, Jeep Driver said: They are MJ and XJ specific, nothing else. Wouldnt 87-90 2.5 Wranglers be the same too?
Jeep Driver Posted February 26, 2018 Posted February 26, 2018 12 minutes ago, FrankTheDog said: Wouldnt 87-90 2.5 Wranglers be the same too? Find one.
sinkrun Posted February 26, 2018 Posted February 26, 2018 Take it to a small machine shop they can fix it.
kryptronic Posted February 26, 2018 Posted February 26, 2018 30 minutes ago, FrankTheDog said: Wouldnt 87-90 2.5 Wranglers be the same too? Wranglers didn't get the HO package until 92, so add 91 as well. Around here (PA) 2.5L Wranglers and parts for them are plentiful.
Jeep Driver Posted February 26, 2018 Posted February 26, 2018 '91 is MPI. I have the '91 aluminum VC, for those is us with TBI, the '91 is the cleanest, less bosses. Find one. Try to find a Renix era PS pulley. AC bracket. I'm not going to beat this subject to death, but, as a guy who spent a couple of years seeking out parts for my own.......... OP, if you cannot find one, send your's out to a carb/TB specialty shop to be rebuilt/new bushings, this is not something you want to screw up. Maybe someone can offer to send him one, if you have one or know where a good one is, send it to him.
FrankTheDog Posted February 26, 2018 Posted February 26, 2018 Wranglers did get the HO in 91 just like the rest of the jeep line. I have the complete wiring harness from one with computer, dash and all sensors to convert my 89 wrangler over.
kryptronic Posted February 26, 2018 Posted February 26, 2018 49 minutes ago, FrankTheDog said: Wranglers did get the HO in 91 just like the rest of the jeep line. I have the complete wiring harness from one with computer, dash and all sensors to convert my 89 wrangler over. Thank you, I stand corrected. 91 was an HO year for the Wrangler. 92-95 have identical electrical setups. 91 still had some mechanical bits like the speedo. I've owned several 95s and when sourcing those parts, I only ever looked back to 92 due to several differences in 91.
carnuck Posted March 12, 2018 Posted March 12, 2018 '91 is MPI. I have the '91 aluminum VC, for those is us with TBI, the '91 is the cleanest, less bosses. Find one. Try to find a Renix era PS pulley. AC bracket. I'm not going to beat this subject to death, but, as a guy who spent a couple of years seeking out parts for my own.......... OP, if you cannot find one, send your's out to a carb/TB specialty shop to be rebuilt/new bushings, this is not something you want to screw up. Maybe someone can offer to send him one, if you have one or know where a good one is, send it to him. I converted to HO PS setup. I kept the ac compressor plate for onboard air. Sent from my iPhone using Tapatalk
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now