No passing gear...
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Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Understood. I meant to write that, but it came out wrong.
So, the latest update.
I adjusted the TPS per cruisers instructions. The output voltage is right on the money.
Starting seems to take 1/2 a second more than it should. It seems like it should catch a little sooner, but that may be my imagination.
The downshifting (passing gear) is working again, so I'm attributing that to the bad/wet TPS.
Something is still off. The engine is not accelerating the way it should, and the passing gear doesn't kick in as soon as it should.
The performance is lackluster, and I've heard one or two small pops out of the throttle body while accelerating.
The engine does seem to responding normally if I'm travelling at 50 mph or so and punch it. Power seems pretty normal then.
It sounds almost like the ignition isn't advancing correctly.
I've always thought I was losing some vacuum through the brake booster, so I bought and installed a new master cylinder/booster.
Any suggestions on what I should check?
I noticed that in your tips, you have a procedure for adjusting the timing manually. Any reason not to use a timing light?
So, the latest update.
I adjusted the TPS per cruisers instructions. The output voltage is right on the money.
Starting seems to take 1/2 a second more than it should. It seems like it should catch a little sooner, but that may be my imagination.
The downshifting (passing gear) is working again, so I'm attributing that to the bad/wet TPS.
Something is still off. The engine is not accelerating the way it should, and the passing gear doesn't kick in as soon as it should.
The performance is lackluster, and I've heard one or two small pops out of the throttle body while accelerating.
The engine does seem to responding normally if I'm travelling at 50 mph or so and punch it. Power seems pretty normal then.
It sounds almost like the ignition isn't advancing correctly.
I've always thought I was losing some vacuum through the brake booster, so I bought and installed a new master cylinder/booster.
Any suggestions on what I should check?
I noticed that in your tips, you have a procedure for adjusting the timing manually. Any reason not to use a timing light?
When you adjusted the TPS, did you use the flat 3 wire connector or the square 4 wire connector for the trans?
Have you done post 10?
Thread Starter
Seasoned Member
Joined: Oct 2012
Posts: 328
Likes: 5
From: Dominican Republic
Year: 1990
Model: Cherokee
Engine: inline 6
I did half of post ten. When I had the thing all torn down, I pulled the ECU to check connections, and everything looked fine and clean.
Are you referring to the C101 connector in post 10? Mine is a 1990.
I pretty much went through all the connections and grounds with a fine tooth comb when I did the restoration.
I'll check the other connector again. Can't hurt.
Last edited by jdjonesdr; Aug 2, 2014 at 09:23 AM.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I used the flat three wire connector. I checked connections on both connectors, but adjusted with the flat 3.
I did half of post ten. When I had the thing all torn down, I pulled the ECU to check connections, and everything looked fine and clean.
Are you referring to the C101 connector in post 10? Mine is a 1990.
I pretty much went through all the connections and grounds with a fine tooth comb when I did the restoration.
I'll check the other connector again. Can't hurt.
I did half of post ten. When I had the thing all torn down, I pulled the ECU to check connections, and everything looked fine and clean.
Are you referring to the C101 connector in post 10? Mine is a 1990.
I pretty much went through all the connections and grounds with a fine tooth comb when I did the restoration.
I'll check the other connector again. Can't hurt.
Thread Starter
Seasoned Member
Joined: Oct 2012
Posts: 328
Likes: 5
From: Dominican Republic
Year: 1990
Model: Cherokee
Engine: inline 6
I'm pretty sure I've checked those connections, but like I said before, there sure isn't any harm in doing it again.
I am also going to try the resistance test you posted. I redid all the grounds (and even added a couple) when I did the restore, but never ohmmed it out. I'll do that to for ****s and giggles.
Also, I just noticed there's a picture, but for some reason, I'm being told I don't have access to it. First time that's happened.
I'll let ya know how it goes on Tuesday if the storm clears up.
Thanks again.
Thread Starter
Seasoned Member
Joined: Oct 2012
Posts: 328
Likes: 5
From: Dominican Republic
Year: 1990
Model: Cherokee
Engine: inline 6
Good morning!
I was able to get under the hood yesterday between downpours.
I did revise those particular connectors when I restored the beast, and they were in really good shape.
Looking at them again yesterday, I confirmed they still look as good as new.
While the engine running still seems to be "off", I can tell you if I leave it in first and accelerate, it really runs like a bat outta hell once the revs get up a little; it's only at idle and beginning to accelerate that it doesn't seem to be right.
I'm going to recheck the TPS adjustment this morning, just in case. Maybe playing around with that a little more will do the trick.
I also noticed in your pictures you have hoses from the cooling system that go in the firewall.
Mine only has one going into the holding tank, and one coming out underneath.
Obviously, my heater has been eliminated at some point in time.
I was able to get under the hood yesterday between downpours.
I did revise those particular connectors when I restored the beast, and they were in really good shape.
Looking at them again yesterday, I confirmed they still look as good as new.
While the engine running still seems to be "off", I can tell you if I leave it in first and accelerate, it really runs like a bat outta hell once the revs get up a little; it's only at idle and beginning to accelerate that it doesn't seem to be right.
I'm going to recheck the TPS adjustment this morning, just in case. Maybe playing around with that a little more will do the trick.
I also noticed in your pictures you have hoses from the cooling system that go in the firewall.
Mine only has one going into the holding tank, and one coming out underneath.
Obviously, my heater has been eliminated at some point in time.
Thread Starter
Seasoned Member
Joined: Oct 2012
Posts: 328
Likes: 5
From: Dominican Republic
Year: 1990
Model: Cherokee
Engine: inline 6
I played around with it yesterday and it seems to have improved, but it still seems a little flat at very low speed, and I'm still getting the occasional "pop" coming out of the throttle body.
Once it accelerates a tad, it really wants to get up and go. Almost like hitting the "Nitrous" switch. lol
Last edited by jdjonesdr; Aug 5, 2014 at 06:34 AM.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
If I'm understanding you correctly, you mean on the engine side of the connector, not the side that goes to the transmission, right?
I played around with it yesterday and it seems to have improved, but it still seems a little flat at very low speed, and I'm still getting the occasional "pop" coming out of the throttle body.
Once it accelerates a tad, it really wants to get up and go. Almost like hitting the "Nitrous" switch. lol
I played around with it yesterday and it seems to have improved, but it still seems a little flat at very low speed, and I'm still getting the occasional "pop" coming out of the throttle body.
Once it accelerates a tad, it really wants to get up and go. Almost like hitting the "Nitrous" switch. lol
Beach Bum
Joined: Jul 2011
Posts: 6,123
Likes: 22
From: Cape Hatteras, North Carolina
Year: 2000 WJ
Model: Grand Cherokee
Engine: 4.0
Thread Starter
Seasoned Member
Joined: Oct 2012
Posts: 328
Likes: 5
From: Dominican Republic
Year: 1990
Model: Cherokee
Engine: inline 6
Thread Starter
Seasoned Member
Joined: Oct 2012
Posts: 328
Likes: 5
From: Dominican Republic
Year: 1990
Model: Cherokee
Engine: inline 6
Latest and greatest.....
I rechecked the voltage on the throttle body side of the connector, and it's the same as the transmission side.
The only comment I would add is my voltmeter only gives me one digit on the voltage, so when I look at it, I see 4.8 and .8 for example. I cannot see the voltage at 4.84, or .82 for example.
So where my calculations tell me the voltage on the throttle body side should be .816, I only know it's between .800 and .899
I'm guessing that's not too critical. Would I be wrong? I can always go out and buy another meter.
I rechecked the voltage on the throttle body side of the connector, and it's the same as the transmission side.
The only comment I would add is my voltmeter only gives me one digit on the voltage, so when I look at it, I see 4.8 and .8 for example. I cannot see the voltage at 4.84, or .82 for example.
So where my calculations tell me the voltage on the throttle body side should be .816, I only know it's between .800 and .899
I'm guessing that's not too critical. Would I be wrong? I can always go out and buy another meter.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Latest and greatest.....
I rechecked the voltage on the throttle body side of the connector, and it's the same as the transmission side.
The only comment I would add is my voltmeter only gives me one digit on the voltage, so when I look at it, I see 4.8 and .8 for example. I cannot see the voltage at 4.84, or .82 for example.
So where my calculations tell me the voltage on the throttle body side should be .816, I only know it's between .800 and .899
I'm guessing that's not too critical. Would I be wrong? I can always go out and buy another meter.
I rechecked the voltage on the throttle body side of the connector, and it's the same as the transmission side.
The only comment I would add is my voltmeter only gives me one digit on the voltage, so when I look at it, I see 4.8 and .8 for example. I cannot see the voltage at 4.84, or .82 for example.
So where my calculations tell me the voltage on the throttle body side should be .816, I only know it's between .800 and .899
I'm guessing that's not too critical. Would I be wrong? I can always go out and buy another meter.
Thread Starter
Seasoned Member
Joined: Oct 2012
Posts: 328
Likes: 5
From: Dominican Republic
Year: 1990
Model: Cherokee
Engine: inline 6
This particular meter (Scientific American) only has one setting for A/C, and one for DC.
Similar to this one, but with even less settings.. lol
Not what you would call a expensive piece of equipment.
I've been considering buying a better one, since the display on mine is getting pretty ragged.