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I failed my emissions horribly!!!!!

388 Views 6 Replies 3 Participants Last post by  xjy173
In Maryland we have emissions every 2 years and we have to put out vehicles on dynometers (treadmills) to test the emissions. I just doubled the state limits for CO and HC(hydrocarbons). There is no question here, because I know why it failed. The reason was that the previous owner disconnected almost all of the vacuum lines on the engine. (**shole). What I really wanted to say here is that I thought it was pretty cool how the guy who was trying to drive my Jeep on the treadmill wasn't used to the torque in Jeeps w/a 4.2. He couldn't keep it from accelerating more than he wanted it to. I looked like it wanted to jump right off of the treadmill. Just thought a few of you may appreciate that one./wwwthreads_images/icons/wink.gif
88 YJ, Sick cylinder, soon to be replaced Crapper BBD(with Holley)
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Here in Denver, 82 and newer also get tested on a dyno. My first try at emmisions (also a horrible failure, a burnt exhaust valve will do that I guess) three different people tried and failed to drive the trace. I had a brand new T-18 in, and the low gears and tight shifting bested the regular tester and two managers. Finally a twenty something girl who was directing traffic in the parking lot took a shot and did it the first time. Who'd a thunk?


82 CJ7, 258, T-18, 4" bigger & size 33 shoes
Hey Beee,
How did you make out with the front axle/vacuum problem?

Still working on it. The problem with the emissions vacuum tubing is the problem with the 4wd. No vacuum to the tcase or anywhere except the carb. I have to take a stab at it as soon as the weather permits. Also, the Haynes has a vacuum diagram, but it sucks. I have to use that diagram to replace the tubing, so I may have alot of cussing to do one day this week.

This may help, Beee. My XJ with 2.8L vacuum supply to the t'case and front axle is teed from the direct manifold connection which also goes to the cannister. It doesn't go to a ported (carburetor) connection, at least on my Cherokee.
Good Luck!!/wwwthreads_images/icons/smile.gif
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Not exactly sure that it is exactly like your 2.8 but it may be a starting point for me. I looked at the diagrams for all of the engines in the 88 YJ, but they don't match up too well even with each other. Thanks anyway.

Yes, the Haynes vacuum diagram for the Cherokee didn't show the vacuum tubing for anything outside the engine compartment. Oddly, both the missing circuits are branched from that direct manifold connection I mentioned. Besides the 4wd connection, the connection for the cabin heater coil also comes from there; the heater coil control comes directly off the storage cannister, the 4wd connection is near the distributor cap, under the air cleaner. Again, Good Luck!/wwwthreads_images/icons/smile.gif
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