I knew the 4.2 and 4.0 shared some parts (swap ala stroker) but was unaware the cams could swap? This is quite interesting!

 

what does an EGR Valve do to a Jeep when it goes bad?

 

Its part of the emission system. Its not serious if it goes bad. It wont need to be replaced immediately. A buddy of mines been drivin around with his broken for a couple months now with no side effects

 

On a 1993 XJ? Nothing. Doesn't have one.

 

Seems I missed this party today lol.

 

Gauge cluster inop need help 98 guages went inop after starting tach temp gas not working checked fuses and now no guages work, did a diagnostic and all passed, all fuses good, have had some issues around fuse pod, but can find none now, checked battery cables, hit and kicked dash, and now after the diag, gas temp oil and voltage all move up to first line, but stay there.

 

Grounds?

 

Sweet ****, please use punctuation next time. That's almost impossible to read. That said, make sure the electrical ground for the gauge cluster is securely attached and free of corrosion

 

a vapor canister essentially replaces an egr?

 

Can you explain to me how a charcoal canister collecting gasoline vapours from the fuel tank to reduce evaporative hydrocarbons from parked vehicles is similar to venting the exhaust back into the intake in order to reduce NOX and CO by lowering combustion temperatures? lol

Renix had evap system & EGR. Chrysler dropped EGR for 1991.

 

My understanding (what I've been told) is that the EGR system was integrated internally in '91. Is that correct?

 

Ok so I'm in a predicament here, it's pretty cold out like 3 degrees outside, my 99 jeep cherokee with a 4.0 first started this problem where it would have the voltmeter drop, it ran fine and everything was good for a while, but it started running terrible and everything inside my car died except for the jeep which was close to dying, so I parked it to get food and wouldn't start back up, it barely cranked and there was a ticking from the starter, so after I came back out after about an hour, I started it up and it started up and idled but very poorly, I tried to drive for a bit and it wanted to die, I was driving down the road for a bit and boom. It went back to normal headlights were fine and radio came back on but still the voltmeter was still down, I finally get home and park it and start it back up, it ran again like nothing was wrong, no check gauges or anything, so my question is what the hell is going on? Is it my battery? Alternator? Or because it's so cold?

 

Maybe, maybe, cold affects battery.
Both ends of ALL battery cables clean and tight? If yes then have battery and alternater tested.

 

I'd say alternator.

 

It can stick open and cause a huge vacuum leak.