I wanted to post this because a simple adjustment solved multiple, seemingly unrelated problems.
I recently had major work ( a Jasper engine install) performed by a reputable shop on my 2000 TJ. When I got the vehicle back, it ran OK, but something was not right. It ran hotter than it had in the past, particularly at freeway speeds. It seemed to be lacking power under certain load conditions. It smelled of fuel after being shut off. Mileage seemed to particularly poor. Under seemingly random conditions, the jeep would "clunk", sometimes related to a downshift, sometimes on an upshift, sometimes for no apparent reason at all. Notably, I was relatively unconcerned about the clunk as the jeep has done that to various degrees since I owned it, but the other symptoms were new since the engine was replaced.
I took it back to the shop, they test drove it, and said everything was within normal operational parameters. The clunking, they said, might be control arms, shocks, or something else with the suspension. The fact that clunking occurred during shifts might indicate it needed transmission service, but they would not be able to figure it out without some (potentially) significant diagnostic cost. They attributed lack of power to high ratio gearing. Jeeps, they said, just ran hot. They noted the fuel odor, but had no answers for htat.
I was reluctant to take it to the back country until I either gained confidence that this performance was not an issue, or I solved the problems. I looked at several items. Control arms were all lubed, and properly fitting. The rear sway link bushings were shot, so I replaced those. That eliminated some squeaks which was nice, but did not reduce the clunking. Coolant level was correct. Belt and Fan operation were good. It never threw any codes.
Finally I ran across a Youtube regarding adjustment of the Throttle Valve linkage, so decided to give that a shot. First thing I found was that the linkage was between 1/4" to 3/8" out of adjustment. I adjusted the cable to the recommended zero tension, zero slack condition and took the jeep for a drive. Immediately, I noticed the clunking was better as there was one particular street nearby at a certain location in the street where I always got a clunk. It was now gone. Subsequently, over several days, I operated the jeep under numerous conditions, and my other symptoms were gone. The engine temperature sat right on 210 (by the dash gauge). Power under load had returned. Mileage got about 15% better. There was no more fuel smell when shutdown. I have operated it on the freeway and in the back country now for two months without issue.
If this comes up in a search and saves one person aggravation, I have done my job.
I recently had major work ( a Jasper engine install) performed by a reputable shop on my 2000 TJ. When I got the vehicle back, it ran OK, but something was not right. It ran hotter than it had in the past, particularly at freeway speeds. It seemed to be lacking power under certain load conditions. It smelled of fuel after being shut off. Mileage seemed to particularly poor. Under seemingly random conditions, the jeep would "clunk", sometimes related to a downshift, sometimes on an upshift, sometimes for no apparent reason at all. Notably, I was relatively unconcerned about the clunk as the jeep has done that to various degrees since I owned it, but the other symptoms were new since the engine was replaced.
I took it back to the shop, they test drove it, and said everything was within normal operational parameters. The clunking, they said, might be control arms, shocks, or something else with the suspension. The fact that clunking occurred during shifts might indicate it needed transmission service, but they would not be able to figure it out without some (potentially) significant diagnostic cost. They attributed lack of power to high ratio gearing. Jeeps, they said, just ran hot. They noted the fuel odor, but had no answers for htat.
I was reluctant to take it to the back country until I either gained confidence that this performance was not an issue, or I solved the problems. I looked at several items. Control arms were all lubed, and properly fitting. The rear sway link bushings were shot, so I replaced those. That eliminated some squeaks which was nice, but did not reduce the clunking. Coolant level was correct. Belt and Fan operation were good. It never threw any codes.
Finally I ran across a Youtube regarding adjustment of the Throttle Valve linkage, so decided to give that a shot. First thing I found was that the linkage was between 1/4" to 3/8" out of adjustment. I adjusted the cable to the recommended zero tension, zero slack condition and took the jeep for a drive. Immediately, I noticed the clunking was better as there was one particular street nearby at a certain location in the street where I always got a clunk. It was now gone. Subsequently, over several days, I operated the jeep under numerous conditions, and my other symptoms were gone. The engine temperature sat right on 210 (by the dash gauge). Power under load had returned. Mileage got about 15% better. There was no more fuel smell when shutdown. I have operated it on the freeway and in the back country now for two months without issue.
If this comes up in a search and saves one person aggravation, I have done my job.
