Still running hot after replacing everything
#46
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Year: 1992
Model: Cherokee
Engine: 4.0L H.O.
Thanks for the post. A lot of good info on thermostats. I love simple solutions even if they mean I messed up but the thermostat is in the right way. I'm fairly positive it's not possible to install backwards because the housing won't allow it (doesn't fit).
I did pull the distributor not long ago for an unrelated issue. My Jeep runs so good though I'd be very surprised if timing was wrong. I'd think you'd have to be pretty far off to cause heating issues and then I'd notice misfiring or pre-detonation. I'll dig my timing light out and check though. Like you said I want to eliminate everything else first.
I did pull the distributor not long ago for an unrelated issue. My Jeep runs so good though I'd be very surprised if timing was wrong. I'd think you'd have to be pretty far off to cause heating issues and then I'd notice misfiring or pre-detonation. I'll dig my timing light out and check though. Like you said I want to eliminate everything else first.
Definitely check that timing, it doesn't have to be quite high enough to cause pinging but can still cause it to run hot. When you're accelerating or under load(which at highway speeds is almost all the time if you don't have the right gears for your tire size) the timing advances. If your base timing is a bit too high, it'll feel like its running great, nice and punchy. But when it advances, you may be reaching the point where it'll start to run hotter. The I6 is a phenomenal engine, but isn't very forgiving of tuning problems.
Again, may not be the problem, but I'll keep my fingers crossed. Timing adjustment sure beats the heck out of a head swap!
#48
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Year: 1992
Model: Cherokee
Engine: 4.0L H.O.
If you're within margin(eg 8-12deg) general rule of thumb;
Retard: less power/cooler temps
Advance: more power/higher temps
Again, going way too far either way is a bad thing. Starting will tell you if you've gone way too far. Too much advance and it cranks like your battery is dying. Too retarded and it cranks like mad, but struggles to fire off. Backfire through intake, too much advance. Backfire out exhaust, too retarded.
#49
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
I fried a 62 Falcon 6 cylinder due to retarded timing. The rotor had cracked near the metal tip and allowed it to move backwards. I'd guess it was something like 10-15 degrees. Heated up very nicely. No gauge, so I didn't know it until it was too late.
#50
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Year: 1994
Model: Cherokee
Engine: 4.0L
Thanks all. Dug the timing light out after work and what do you know the bulb was out. I'm going to swing by harbor freight tomorrow and pick up a new one but probably won't be able to work on it again until Wednesday. I'll post an update then.
#51
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Year: 1992
Model: Cherokee
Engine: 4.0L H.O.
We had a little Mustang with a siezed 200 come in, oil pump locked up, sheared the drive gear off the dissy shaft. So everything was pointing every which way but right, lol. Chicken or the egg?
#54
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Year: 1994
Model: Cherokee
Engine: 4.0L
I checked the timing and it looks like I'm between 14 and 15 degrees (advanced). Moving a tooth on the distributor (or even on the timing chain) I feel would be too great an adjustment when I only need to move 2-6 degrees. Is there any other way to adjust timing on these 4.0s? What would cause advanced timing. Plug 1 is at 5 o'clock as firestorm said it should be.
#55
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Year: 1994
Model: Cherokee
Engine: 4.0L
So I did a bit of googling (shocker I know) and see the dizzy isn't adjustable like those of old, and all indications point to it being installed properly. Looks like some people slot the mount for the CPS (jeep speed guys), but other than that the timing isn't really adjustable top side. I wonder if it's possible my chain is a tooth off? I know the PO had a new timing set installed, no idea why, I just have a receipt for it. Thinking out loud....
#57
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Year: 1992
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So I did a bit of googling (shocker I know) and see the dizzy isn't adjustable like those of old, and all indications point to it being installed properly. Looks like some people slot the mount for the CPS (jeep speed guys), but other than that the timing isn't really adjustable top side. I wonder if it's possible my chain is a tooth off? I know the PO had a new timing set installed, no idea why, I just have a receipt for it. Thinking out loud....
#59
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Year: 1994
Model: Cherokee
Engine: 4.0L
#60
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Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
Based on my previous experience with used/remanufactured heads, which I have already posted about, I personally would only buy a brand new, complete aftermarket head.
It's just too much work, time, and frustration messing around with anything else.
It's just too much work, time, and frustration messing around with anything else.