1987 4.0 compression
10-21-2014, 11:18 PM
#1
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Year: 1987
Model: Cherokee
Engine: 4.0 Renix
1987 4.0 compression
1987xj with 4.0. 210k miles, been having backfiring issues. Did a compression test.
1. 135
2 155
3. 155
4. 155
5. 155
6. 145
Just curious what you guys think?
1. 135
2 155
3. 155
4. 155
5. 155
6. 145
Just curious what you guys think?
10-22-2014, 01:31 AM
#4
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Linky:
https://www.cherokeeforum.com/f23/te...itings-136452/
Backfiring out the exhaust or in the intake?
https://www.cherokeeforum.com/f23/te...itings-136452/
Backfiring out the exhaust or in the intake?
10-22-2014, 01:49 AM
#5
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Year: 1987
Model: Cherokee
Engine: 4.0 Renix
Linky:
https://www.cherokeeforum.com/f23/te...itings-136452/
Backfiring out the exhaust or in the intake?
10-22-2014, 02:02 AM
#6
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Might start with a fuel pressure check, could be a lean condition. Also check for damage to the ignition system, damaged fuel injector wiring, MAP problems, vacuum leaks..
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10-22-2014, 07:44 PM
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Year: 90,84
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Engine: 4.0,2.5
39# with the vacuum line off the regulator (on the front of the fuel rail), and about 10 less with it on.
Cruisers stuff will likely help you, in allot of ways. The sensors won't sense right if the grounds are not good, and the info won't make it to the puter' if the C-101 connector is crap. Then the CPS check...it's the "heartbeat", won't work well if that's funky!
Cruisers stuff will likely help you, in allot of ways. The sensors won't sense right if the grounds are not good, and the info won't make it to the puter' if the C-101 connector is crap. Then the CPS check...it's the "heartbeat", won't work well if that's funky!
10-23-2014, 07:40 AM
#9
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Year: 1990
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10-23-2014, 06:02 PM
#10
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Year: 1987
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10-23-2014, 06:05 PM
#11
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10-23-2014, 06:21 PM
#12
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10-24-2014, 07:56 PM
#13
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Year: 1987
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Backfiring out the exhaust or in the intake?
10-24-2014, 08:18 PM
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I think that is was Radi was getten at in post #6, being lean making it backfire. No ****! It never goes up to closer to 40?...looks like you guy's found the problem.