88 4.0 Runs Rough After Engine Rebuild, tried everything, nothing helps
02-15-2018, 11:01 AM
#46
Junior Member
Thread Starter
Join Date: Jan 2017
Location: North Carolina (southeastern NC)
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1988
Engine: 4.0L
02-15-2018, 07:24 PM
#47
Junior Member
Thread Starter
Join Date: Jan 2017
Location: North Carolina (southeastern NC)
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1988
Engine: 4.0L
Red Kote tank liner instead of replacement?
When I went to order the tank I discovered Red Kote Fuel Tank Liner.
Once I got the tank cleaned it appears that all of that nasty mess is just surface rust.
If I prep the tank properly, I'm thinking I should be able to seal it, which would leave me with better than a new, unlined tank and cost about $50 with the liner and the prep materials.
I've read a lot of good things about it when I researched even that if the tank had a small pinhole it would fill ans seal it. My tank is only about 5 or 6 years old, so most of the issues are from the gas sitting for 7 months while I had the engine out.
Has anyone ever used this on their Jeep?
If so, please share your thoughts.
Once I got the tank cleaned it appears that all of that nasty mess is just surface rust.
If I prep the tank properly, I'm thinking I should be able to seal it, which would leave me with better than a new, unlined tank and cost about $50 with the liner and the prep materials.
I've read a lot of good things about it when I researched even that if the tank had a small pinhole it would fill ans seal it. My tank is only about 5 or 6 years old, so most of the issues are from the gas sitting for 7 months while I had the engine out.
Has anyone ever used this on their Jeep?
If so, please share your thoughts.
03-01-2018, 02:40 AM
#48
Junior Member
Thread Starter
Join Date: Jan 2017
Location: North Carolina (southeastern NC)
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1988
Engine: 4.0L
UPDATE: Fuel System cleaned out/replaced/refurbished, still not fixed
OK, I've spent the last several weeks cleaning and replacing fuel system components, but its still not running right - same issue (idles rough but halfway decent, then falls on its face when I try to open the throttle).
Here's what I've done :
1) Removed and cleaned gas tank, then coated with Red Kote fuel tank liner. (Soaked in vinegar overnight, washed with Dawn dish detergent, flushed with water, dried in sun, rinsed with acetone (to remove remaining water), then immediately coated interior of tank with Red Kote)
2) Replaced Fuel Pump
3) Replaced Fuel Pump Hoses
4) Replaced Fuel Filter
5) Cleaned out all fuel pressure and return lines (pushed lacquer thinner through the lines with a syringe, then fashioned a sort of "IV drip" and tapped the lines to release the air bubbles. As the bubbles were released from the walls of the fuel lines, the atmospheric pressure forced more solvent in, ensuring that all surfaces were contacted and soaked. I let it sit overnight, then flushed with more thinner from the syringe. It worked REALLY well.)
6) Replaced Fuel Injectors (with 4-hole injectors from Volvo I think? Bosch Part#0280155746 )
After all of that, it still runs the same, although the fuel trim is a bit more stable and the exhaust is running RICH, as opposed to how it was running LEAN before with fuel trim maxing out (I think that maybe the ECM was trying to compensate for the little bit of gasoline that was left in that pink rusty sludge that I was burning.)
Still, problem still there, with all that I've done (reindex distributor several times, replaced fuel system, replaced half of my sensors and confirmed that tall are putting out within limits), with all of this, what else could it possibly be?
Here's what I've done :
1) Removed and cleaned gas tank, then coated with Red Kote fuel tank liner. (Soaked in vinegar overnight, washed with Dawn dish detergent, flushed with water, dried in sun, rinsed with acetone (to remove remaining water), then immediately coated interior of tank with Red Kote)
2) Replaced Fuel Pump
3) Replaced Fuel Pump Hoses
4) Replaced Fuel Filter
5) Cleaned out all fuel pressure and return lines (pushed lacquer thinner through the lines with a syringe, then fashioned a sort of "IV drip" and tapped the lines to release the air bubbles. As the bubbles were released from the walls of the fuel lines, the atmospheric pressure forced more solvent in, ensuring that all surfaces were contacted and soaked. I let it sit overnight, then flushed with more thinner from the syringe. It worked REALLY well.)
6) Replaced Fuel Injectors (with 4-hole injectors from Volvo I think? Bosch Part#0280155746 )
After all of that, it still runs the same, although the fuel trim is a bit more stable and the exhaust is running RICH, as opposed to how it was running LEAN before with fuel trim maxing out (I think that maybe the ECM was trying to compensate for the little bit of gasoline that was left in that pink rusty sludge that I was burning.)
Still, problem still there, with all that I've done (reindex distributor several times, replaced fuel system, replaced half of my sensors and confirmed that tall are putting out within limits), with all of this, what else could it possibly be?
03-01-2018, 07:56 AM
#49
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
OK, I've spent the last several weeks cleaning and replacing fuel system components, but its still not running right - same issue (idles rough but halfway decent, then falls on its face when I try to open the throttle).
Here's what I've done :
1) Removed and cleaned gas tank, then coated with Red Kote fuel tank liner. (Soaked in vinegar overnight, washed with Dawn dish detergent, flushed with water, dried in sun, rinsed with acetone (to remove remaining water), then immediately coated interior of tank with Red Kote)
2) Replaced Fuel Pump
3) Replaced Fuel Pump Hoses
4) Replaced Fuel Filter
5) Cleaned out all fuel pressure and return lines (pushed lacquer thinner through the lines with a syringe, then fashioned a sort of "IV drip" and tapped the lines to release the air bubbles. As the bubbles were released from the walls of the fuel lines, the atmospheric pressure forced more solvent in, ensuring that all surfaces were contacted and soaked. I let it sit overnight, then flushed with more thinner from the syringe. It worked REALLY well.)
6) Replaced Fuel Injectors (with 4-hole injectors from Volvo I think? Bosch Part#0280155746 )
After all of that, it still runs the same, although the fuel trim is a bit more stable and the exhaust is running RICH, as opposed to how it was running LEAN before with fuel trim maxing out (I think that maybe the ECM was trying to compensate for the little bit of gasoline that was left in that pink rusty sludge that I was burning.)
Still, problem still there, with all that I've done (reindex distributor several times, replaced fuel system, replaced half of my sensors and confirmed that tall are putting out within limits), with all of this, what else could it possibly be?
Here's what I've done :
1) Removed and cleaned gas tank, then coated with Red Kote fuel tank liner. (Soaked in vinegar overnight, washed with Dawn dish detergent, flushed with water, dried in sun, rinsed with acetone (to remove remaining water), then immediately coated interior of tank with Red Kote)
2) Replaced Fuel Pump
3) Replaced Fuel Pump Hoses
4) Replaced Fuel Filter
5) Cleaned out all fuel pressure and return lines (pushed lacquer thinner through the lines with a syringe, then fashioned a sort of "IV drip" and tapped the lines to release the air bubbles. As the bubbles were released from the walls of the fuel lines, the atmospheric pressure forced more solvent in, ensuring that all surfaces were contacted and soaked. I let it sit overnight, then flushed with more thinner from the syringe. It worked REALLY well.)
6) Replaced Fuel Injectors (with 4-hole injectors from Volvo I think? Bosch Part#0280155746 )
After all of that, it still runs the same, although the fuel trim is a bit more stable and the exhaust is running RICH, as opposed to how it was running LEAN before with fuel trim maxing out (I think that maybe the ECM was trying to compensate for the little bit of gasoline that was left in that pink rusty sludge that I was burning.)
Still, problem still there, with all that I've done (reindex distributor several times, replaced fuel system, replaced half of my sensors and confirmed that tall are putting out within limits), with all of this, what else could it possibly be?
Last edited by Bugout4x4; 03-01-2018 at 07:59 AM.
03-01-2018, 09:59 AM
#50
Junior Member
Thread Starter
Join Date: Jan 2017
Location: North Carolina (southeastern NC)
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1988
Engine: 4.0L
I tried two other ECMs that were loaned to me, but they were out of vehicles that the guy had never had running, and one of them had muddy water coming out of it when I disconnected it from my XJ, so I can't be sure that these were good either.
Does it look like I should buy a remanufactured one that I could be relatively certain is operational? Found one at NAPA for $149 plus core (Jeep dealership suggested NAPA, they said it was where there got the ones that Jeep no longer makes). I don't really have the funds to get it, but I'll have to make a way if it looks like it could be the culprit.
Thoughts?
***By the way, I had to replace my TCU about a year before due to trans not shifting out of 1st gear automatically - tried everything else, after replacing trans computer it fixed it. Don't know if there is anything that may have happened in my electrical system to cause this, but I know they are rare to go out too.
Last edited by PapaBearXJ88; 03-01-2018 at 10:04 AM. Reason: By the way, I had to replace my TCU about a year before due to trans not shifting -tried everything else, replacing TCU fixed
03-02-2018, 06:21 AM
#53
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
I wouldn't throw a new computer at it just yet. I am not familiar with the system on your 88 but could go drag up some diagrams to find out. But do these have a Mass Air Flow sensor? It sounds like it will run with the throttle plate closed but as soon as you introduce more air flow it quits. (or reduced vacuum, or increased timing advance).
I had to go deal with something yesterday and got locked in and couldn't come back.
I had to go deal with something yesterday and got locked in and couldn't come back.
03-02-2018, 11:15 AM
#54
Junior Member
Thread Starter
Join Date: Jan 2017
Location: North Carolina (southeastern NC)
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1988
Engine: 4.0L
This was one of the possibilities I looked at regarding the rough running. I inspected the balancer, it had a few small cracks in the rubber, but all of it seems to be intact and in place.
The reason I rechecked with the camera was to double check timing to make sure I was at TDC #1 when I indexed it. The timing mark was near the zero when at TDC, a little before. Even so, this would only be an adjustment of of 2-3 degrees of advance. Since the ECM will advance from 13-20 degrees or so based on engine conditions, would it make a big difference if the balancer was off by a few degrees?
I am going to try to get a timing light this weekend and see exactly what it is doing at idle and then again when I try to open the throttle.
03-02-2018, 11:30 AM
#55
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
Yes, that me.
This was one of the possibilities I looked at regarding the rough running. I inspected the balancer, it had a few small cracks in the rubber, but all of it seems to be intact and in place.
The reason I rechecked with the camera was to double check timing to make sure I was at TDC #1 when I indexed it. The timing mark was near the zero when at TDC, a little before. Even so, this would only be an adjustment of of 2-3 degrees of advance. Since the ECM will advance from 13-20 degrees or so based on engine conditions, would it make a big difference if the balancer was off by a few degrees?
I am going to try to get a timing light this weekend and see exactly what it is doing at idle and then again when I try to open the throttle.
This was one of the possibilities I looked at regarding the rough running. I inspected the balancer, it had a few small cracks in the rubber, but all of it seems to be intact and in place.
The reason I rechecked with the camera was to double check timing to make sure I was at TDC #1 when I indexed it. The timing mark was near the zero when at TDC, a little before. Even so, this would only be an adjustment of of 2-3 degrees of advance. Since the ECM will advance from 13-20 degrees or so based on engine conditions, would it make a big difference if the balancer was off by a few degrees?
I am going to try to get a timing light this weekend and see exactly what it is doing at idle and then again when I try to open the throttle.
I think you have something else going on here. I have been looking around here and there on another tab.
03-02-2018, 12:08 PM
#56
CF Veteran
Join Date: Mar 2010
Location: Broward County Fl.
Posts: 47,923
Likes: 0
Received 29 Likes
on
28 Posts
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
. Being off 1 tooth in the old days didnt mean much. You just turn the dist. Computer controlled cars relly on Crank and Cam to be set at exact point which is sent to ecm.
Last edited by freegdr; 03-02-2018 at 12:14 PM.
03-03-2018, 11:10 AM
#58
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
Gotta be perfect......https://www.cherokeeforum.com/f2/94-...g-issue-91667/
Since then I came in here and found a post where one of the geniuses here pointed out the hole that you pin through to lock the rotor with the correct indexing with the housing, then put it in on TDC. But to do this you have to use a long screwdriver to index the oil pump slot to match and start as you twist it in. If it lands with the hold down bolt hole lined up it is correct, if not you are off a tooth and it will show you which direction. But you have to turn the pump drive again to change it. The thread is here somewhere... I think it was Cruiser or "CCKen" who shared this if I remember right?
In the mean time I am still looking, just have lot of irons in the fire right now and have to drop in here once in awhile to clear my head from the other tasks. Sure wish Cruiser would drop in... Have you checked out his site yet? Fantastic knowledge he shares there!
http://www.cruiser54.com/
03-03-2018, 11:55 AM
#59
Junior Member
Thread Starter
Join Date: Jan 2017
Location: North Carolina (southeastern NC)
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1988
Engine: 4.0L
Could CPS or Sync Sensor cause any of these issues?
Mine was bad when I got it. I had a heck of a time getting it indexed correctly and I have done this to all makes and engines hundreds of times. What kept messing with me was the computer compensating for me actually being off a tooth either way. The old housing I took out had an adjustable slot for the hold down bolt, the new one did not. Every time I re-indexed it, it would run rough for a minute then clear it's self up. So I actually had three tooth positions where it would run fine at an idle and it confused me. I finally picked the one in the middle and it was right for acceleration Etc.
Since then I came in here and found a post where one of the geniuses here pointed out the hole that you pin through to lock the rotor with the correct indexing with the housing, then put it in on TDC. But to do this you have to use a long screwdriver to index the oil pump slot to match and start as you twist it in. If it lands with the hold down bolt hole lined up it is correct, if not you are off a tooth and it will show you which direction. But you have to turn the pump drive again to change it. The thread is here somewhere... I think it was Cruiser or "CCKen" who shared this if I remember right?
In the mean time I am still looking, just have lot of irons in the fire right now and have to drop in here once in awhile to clear my head from the other tasks. Sure wish Cruiser would drop in... Have you checked out his site yet? Fantastic knowledge he shares there!
http://www.cruiser54.com/
Since then I came in here and found a post where one of the geniuses here pointed out the hole that you pin through to lock the rotor with the correct indexing with the housing, then put it in on TDC. But to do this you have to use a long screwdriver to index the oil pump slot to match and start as you twist it in. If it lands with the hold down bolt hole lined up it is correct, if not you are off a tooth and it will show you which direction. But you have to turn the pump drive again to change it. The thread is here somewhere... I think it was Cruiser or "CCKen" who shared this if I remember right?
In the mean time I am still looking, just have lot of irons in the fire right now and have to drop in here once in awhile to clear my head from the other tasks. Sure wish Cruiser would drop in... Have you checked out his site yet? Fantastic knowledge he shares there!
http://www.cruiser54.com/
I've also reindexed with Cruisers method several times. Guess I may need to do it again - he said that the rotor should be .020 past #1 tower to be right. I indexed it into place at TDC then rotated the housing until it was at .020 using a feeler gauge.
I was thinking, I changed the Crank Position Sensor during the rebild just because it was at least 20 years old, could it be causing anything relating to timing? I have read that CPS affects timing, but it is usually a no start condition. What affect would the sync / cam position sensor (in the distributor) have on timing? Could either cause any of these issues?
Last edited by PapaBearXJ88; 03-03-2018 at 11:57 AM. Reason: title missing
03-03-2018, 12:04 PM
#60
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
Thanks Bugout, I may try to loo for a new distributor housing wit the toes still on it. I know it is still possible to set it with the toes off, but at least that would take away that variable of being off with the housing. But then again, the reason the guy at the shop had me grind them off was becuae it was running like this before I did.
I've also reindexed with Cruisers method several times. Guess I may need to do it again - he said that the rotor should be .020 past #1 tower to be right. I indexed it into place at TDC then rotated the housing until it was at .020 using a feeler gauge.
I was thinking, I changed the Crank Position Sensor during the rebild just because it was at least 20 years old, could it be causing anything relating to timing? I have read that CPS affects timing, but it is usually a no start condition. What affect would the sync / cam position sensor (in the distributor) have on timing? Could either cause any of these issues?
I've also reindexed with Cruisers method several times. Guess I may need to do it again - he said that the rotor should be .020 past #1 tower to be right. I indexed it into place at TDC then rotated the housing until it was at .020 using a feeler gauge.
I was thinking, I changed the Crank Position Sensor during the rebild just because it was at least 20 years old, could it be causing anything relating to timing? I have read that CPS affects timing, but it is usually a no start condition. What affect would the sync / cam position sensor (in the distributor) have on timing? Could either cause any of these issues?