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Unread 08-19-2013, 10:07 AM   #1
79chiefs
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???egr???

So I have been driving the $#!^ out of this 88XJ to get the fuel cleaner throughout the system doing its job. But while slowing down for kids to cross the road it died. I got it started and it is idling rough again. It runs great, has much more power than my 92 did. But at idle it runs rough/dies, also has a bit of hesitation from WOT when getting onto the highway, but once it gets out of the hesitation it will spin the tires from a stop. I also hear a slight tick when giving it throttle. No it is not lifter tick, or metallic, i have lifter tick, this is like something moving, an electronic. It sounds like under the dash, or under the intake possibly. It is hard to tell, but happens once I press the accelerator, but it is AFTER the hesitation from WOT.
I began to think my EGR valve, but do not know how to test it, or what valve it is, i have two next to the intake.

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79 FSJ Cherokee Chief 350SBC-SOLD_88 XJ Laredo I6 Auto 4wd-SOLD_92 XJ Laredo I6 Auto 4wd-SOLD
99 WJ Laredo I6 Auto 2wd-TOTALED still fathers DD till repairs are made
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Unread 08-19-2013, 01:22 PM   #2
BassMasterCHS
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Just a thought, maybe the spark plugs are fouled up from burning all the built up garbage...
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Unread 08-19-2013, 01:36 PM   #3
79chiefs
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I had a new set in, replaced them last week and bought a spark plug cleaner. Took them out and cleaned them earlier, they were ok, but to double check i cleaned them, no gapping occurred and it changed nothing.
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79 FSJ Cherokee Chief 350SBC-SOLD_88 XJ Laredo I6 Auto 4wd-SOLD_92 XJ Laredo I6 Auto 4wd-SOLD
99 WJ Laredo I6 Auto 2wd-TOTALED still fathers DD till repairs are made
95 E34 540i-DD
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Unread 08-19-2013, 05:47 PM   #4
cruiser54
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Test the EGR.


TESTING THE EGR VALVE FOR 87-90 4.0 ENGINE

Valve Opening Test
1) With engine at normal operating temperature and at idle,
rapidly open and close throttle. Open throttle sufficiently to obtain
at least 1500 RPM. Movement should be noticed in EGR diaphragm.
2) If diaphragm does not move, probable causes are: faulty
vacuum signal to EGR, defective EGR diaphragm or defective
backpressure sensor diaphragm (if equipped), or leaks in vacuum lines
or connections.
Valve Closing Test
1) With engine at normal operating temperature and at idle,
manually depress EGR valve diaphragm. RPM should immediately drop,
indicating that EGR valve is not leaking and had been properly cutting
off exhaust gas flow at idle.
2) If there is no change in RPM and engine is idling
properly, exhaust gases are not reaching combustion chamber. Check for
plugged passage between EGR valve and intake manifold.
3) If engine idles poorly and RPM is not greatly affected by
manually moving diaphragm up, EGR valve is not closing off exhaust gas
flow. Check for carbon between pintle, leaking EGR valve gasket or bad
EGR valve.
***************
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If you own a Renix Jeep, you'll want to check this out. >

An index to over 25 write-ups can be found in Post #1.

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Unread 08-19-2013, 08:48 PM   #5
79chiefs
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I looked at manually pressing it, can't see how.
I did the opening test, it moves very slightly.
I found a thread about the solenoid.
It said check for vacuum at the supply line next to the connector. I had vacuum there.
Next it said check the line going out, it should have no vacuum at idle. I had just as much vacuum there as the supply.
But it also has a check valve. Should the valve be pulling air into the solenoid? Mine pulls air. Also air rushes out once the engine is off.
To test that I started the engine, put elec tape over the valve and drove it. It seemed to run about the same, im not sure though. But when i shut it off it blew the tape off to let air out, which i though was odd.
If i leave the tape on to start it my jeep has a HIGH idle, not normal high idle at all, VERY HIGH, but is fine when started with the tape off, just runs rough.
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79 FSJ Cherokee Chief 350SBC-SOLD_88 XJ Laredo I6 Auto 4wd-SOLD_92 XJ Laredo I6 Auto 4wd-SOLD
99 WJ Laredo I6 Auto 2wd-TOTALED still fathers DD till repairs are made
95 E34 540i-DD
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Unread 08-20-2013, 06:06 AM   #6
cruiser54
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Reach your fingertips into the big bell and pull the diaphragm back towards you.
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Quote:
Originally Posted by chris87xj View Post
If you own a Renix Jeep, you'll want to check this out. >

An index to over 25 write-ups can be found in Post #1.

Cruiser's Mostly Renix Tips
Refresh*Connections*Before*Replacing*Components
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Unread 08-20-2013, 05:01 PM   #7
79chiefs
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It moves when the engine is off, but i bent my screwdriver trying to move it with it running. I took the vacuum off it, and moved it and it almost died, so i guess it is working. Could it have too much vacuum, i know this is stupid, but when i take a line off and put an old rubber connector in place that has a hole in it the jeep runs better, not necessarily higher idle but better. Also have better braking.
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79 FSJ Cherokee Chief 350SBC-SOLD_88 XJ Laredo I6 Auto 4wd-SOLD_92 XJ Laredo I6 Auto 4wd-SOLD
99 WJ Laredo I6 Auto 2wd-TOTALED still fathers DD till repairs are made
95 E34 540i-DD
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Unread 08-20-2013, 05:39 PM   #8
cruiser54
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I wonder if the diaphragm has a hole in it. Jout for testing purposes, plug all vacuum to the EGR.
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Quote:
Originally Posted by chris87xj View Post
If you own a Renix Jeep, you'll want to check this out. >

An index to over 25 write-ups can be found in Post #1.

Cruiser's Mostly Renix Tips
Refresh*Connections*Before*Replacing*Components
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Unread 08-20-2013, 05:46 PM   #9
79chiefs
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Is it supposed to move with vacuum, mine does not, but does move without vacuum. The jeep idles better when the egr vacuum is disconnected. Let me try one more test plug the line in and run it without the egr solenoid having vacuum. Also is the check valve supposed to pull air in? When i plug it the jeep runs better, but it PUSHES air back out and blows my tape off it, if it is plugged when starting, the jeep runs like i am giving it gas.
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79 FSJ Cherokee Chief 350SBC-SOLD_88 XJ Laredo I6 Auto 4wd-SOLD_92 XJ Laredo I6 Auto 4wd-SOLD
99 WJ Laredo I6 Auto 2wd-TOTALED still fathers DD till repairs are made
95 E34 540i-DD
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Unread 08-20-2013, 05:50 PM   #10
cruiser54
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Unplug vacuum from the solenoid like you're thinking of and report back.
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Quote:
Originally Posted by chris87xj View Post
If you own a Renix Jeep, you'll want to check this out. >

An index to over 25 write-ups can be found in Post #1.

Cruiser's Mostly Renix Tips
Refresh*Connections*Before*Replacing*Components
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Unread 08-20-2013, 06:35 PM   #11
79chiefs
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It has a high idle even with the line plugged. But here is the weird part, i think the solenoid is still pulling vacuum somehow. I plug the vacuum line, and feel the nipple where the line connects and it feels like air is still being pulled into the solenoid. Possibly the egr valve? Can i just eliminate the system? If i do will my idle go down. I need to buy a tach or replace my cluster with one that has a tach.
While i am on that. I cannot find a full cluster 91-, mine is all gauges, but has no tach. Can i use a cluster from a 92+ and modify it to use a cable driven speedo?
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79 FSJ Cherokee Chief 350SBC-SOLD_88 XJ Laredo I6 Auto 4wd-SOLD_92 XJ Laredo I6 Auto 4wd-SOLD
99 WJ Laredo I6 Auto 2wd-TOTALED still fathers DD till repairs are made
95 E34 540i-DD
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Unread 08-20-2013, 06:38 PM   #12
cruiser54
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Remove the EGR valve and see if you can blow through the pintle end of it. Hint: Your mouth will be black.
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Quote:
Originally Posted by chris87xj View Post
If you own a Renix Jeep, you'll want to check this out. >

An index to over 25 write-ups can be found in Post #1.

Cruiser's Mostly Renix Tips
Refresh*Connections*Before*Replacing*Components
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Unread 08-20-2013, 07:03 PM   #13
79chiefs
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Well it is dark now, I'll get to it asap, tomorrow after work i have orientation, and got to run errands after that so may not get to it then. I may just check the price of it and buy a new one anyways. It has been there a long time, and may have dried up from setting so long.
What do you recommend doing with the gauges?
They refuse to work, although everything tests fine.
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79 FSJ Cherokee Chief 350SBC-SOLD_88 XJ Laredo I6 Auto 4wd-SOLD_92 XJ Laredo I6 Auto 4wd-SOLD
99 WJ Laredo I6 Auto 2wd-TOTALED still fathers DD till repairs are made
95 E34 540i-DD
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Unread 08-21-2013, 06:17 AM   #14
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Quote:
Originally Posted by 79chiefs View Post
Well it is dark now, I'll get to it asap, tomorrow after work i have orientation, and got to run errands after that so may not get to it then. I may just check the price of it and buy a new one anyways. It has been there a long time, and may have dried up from setting so long.
What do you recommend doing with the gauges?
They refuse to work, although everything tests fine.
Refresh me on the gauge deal.
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Quote:
Originally Posted by chris87xj View Post
If you own a Renix Jeep, you'll want to check this out. >

An index to over 25 write-ups can be found in Post #1.

Cruiser's Mostly Renix Tips
Refresh*Connections*Before*Replacing*Components
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Unread 08-21-2013, 04:47 PM   #15
79chiefs
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Well surprise thunderstorm on the way home, can't get to the jeep tonight.
So i took them out because no lights worked, only one turn signal. It had corroded contacts, and rusty screws. Put it in and still had light issues, and two gauges still did not work all the time. Took it out again and used electric parts clean and fine sandpaper. Put it in and everything worked great, after a rainstorm they started acting up. Now i have no voltage gauge, the fuel stays at the middle with the low fuel light, and my temp and oil sometimes point left and right, and sometimes they sorta work. Now the temp is stuck at just over 100, and the oil does what ever it wants. Every now and then those two work. I cleaned the ground, and even tapped into it and added ground under the hood. My cluster does not have tach, which i want, but i only find dummy lights in renix jeeps at the JY.
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79 FSJ Cherokee Chief 350SBC-SOLD_88 XJ Laredo I6 Auto 4wd-SOLD_92 XJ Laredo I6 Auto 4wd-SOLD
99 WJ Laredo I6 Auto 2wd-TOTALED still fathers DD till repairs are made
95 E34 540i-DD
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