88 4.0 Runs Rough After Engine Rebuild, tried everything, nothing helps
03-03-2018, 12:09 PM
#61
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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?
03-03-2018, 12:30 PM
#62
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Timing is NOT the real issue with a REnix dizzy out of index.
Distributor indexing explained
For clarification though, that’s not a cam sensor inside the Renix dizzy. It’s there to fire the injectors sequentially with the firing order. You’ll never notice if it went bad because the ECU will try to “guess” where it is and does a heck of a job at it.
As for the “timing”, it is controlled by the ECU. Ever notice how wide the tip of the rotor is? Try and wrap your head around this:
When the ECU yells “Fire” to the ignition control module, where is the rotor in relationship to the dizzy terminal? Not to the terminal yet? Past the terminal too far?
What happens to the spark/secondary ignition strength when it has to jump the Grand Canyon in comparison to shooting from a rotor tip?
Distributor indexing explained
For clarification though, that’s not a cam sensor inside the Renix dizzy. It’s there to fire the injectors sequentially with the firing order. You’ll never notice if it went bad because the ECU will try to “guess” where it is and does a heck of a job at it.
As for the “timing”, it is controlled by the ECU. Ever notice how wide the tip of the rotor is? Try and wrap your head around this:
When the ECU yells “Fire” to the ignition control module, where is the rotor in relationship to the dizzy terminal? Not to the terminal yet? Past the terminal too far?
What happens to the spark/secondary ignition strength when it has to jump the Grand Canyon in comparison to shooting from a rotor tip?
03-07-2018, 02:18 PM
#63
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Year: 1988
Engine: 4.0L
03-07-2018, 02:43 PM
#64
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Year: 1988
Engine: 4.0L
Strong Spark, appears to be in firing on time
Timing is NOT the real issue with a REnix dizzy out of index.
Distributor indexing explained
For clarification though, that’s not a cam sensor inside the Renix dizzy. It’s there to fire the injectors sequentially with the firing order. You’ll never notice if it went bad because the ECU will try to “guess” where it is and does a heck of a job at it.
As for the “timing”, it is controlled by the ECU. Ever notice how wide the tip of the rotor is? Try and wrap your head around this:
When the ECU yells “Fire” to the ignition control module, where is the rotor in relationship to the dizzy terminal? Not to the terminal yet? Past the terminal too far?
What happens to the spark/secondary ignition strength when it has to jump the Grand Canyon in comparison to shooting from a rotor tip?
Distributor indexing explained
For clarification though, that’s not a cam sensor inside the Renix dizzy. It’s there to fire the injectors sequentially with the firing order. You’ll never notice if it went bad because the ECU will try to “guess” where it is and does a heck of a job at it.
As for the “timing”, it is controlled by the ECU. Ever notice how wide the tip of the rotor is? Try and wrap your head around this:
When the ECU yells “Fire” to the ignition control module, where is the rotor in relationship to the dizzy terminal? Not to the terminal yet? Past the terminal too far?
What happens to the spark/secondary ignition strength when it has to jump the Grand Canyon in comparison to shooting from a rotor tip?
With ignition advanced to 14-15 (according to the REM reading from the ECM), I set the light to around 15 degrees on the adjustment dial that is on the timing gun, and at idle the timing mark on the balancer was showing #1 firing right at the 0 on timing tab, then at around 5 degrees BTDC, then back to 0 (which I suspect may have been when it was switching between open and closed loop)
Seems to me like timing is OK, am I right?
One thing that I did notice - when the ECM goes into Closed Loop, it starts dropping from the 128 default for Short Term Fuel Trim, all the way down to around 2-3, and sometime 0, and the exhaust gas continues to show RICH (before cleaning out the fuel system, it was the opposite - LEAN exhaust and STFT maxing out at 255).
03-07-2018, 03:01 PM
#65
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Year: 1988
Engine: 4.0L
Flexplate made in Mexico - ATP Automotive
I just had someone suggest that flex plates made in Mexico were no good.
I checked the one that I put in - it is ATP Automotive part # Z-205. I researched it a bit and found out from the ATP website that they changed ownership to a company out of Monterry, Mexico last year.
Not sure about all of this, but could a bad flex plate be the problem?
I checked the one that I put in - it is ATP Automotive part # Z-205. I researched it a bit and found out from the ATP website that they changed ownership to a company out of Monterry, Mexico last year.
Not sure about all of this, but could a bad flex plate be the problem?
03-07-2018, 03:06 PM
#66
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Year: 1988
Model: Cherokee
Engine: 4.0
Note from DJ
This is the information that I found on line from Advance Auto.
These part numbers don’t match yours.
Advance Auto link for parts below.
https://shop.advanceautoparts.com/we...eIdSearch=8502
CARQUEST New Flywheel
#50-1004
Exact Fit for your 1988 Jeep Cherokee
Clutch Flywheel
Valeo Steel Flywheel
#V2072
Exact Fit for your 1988 Jeep Cherokee
Clutch Flywheel; Flywheel; disc size: 10 3/8 x 1 1/8 x 10
Omix-Ada Automatic Transmission Flexplate
#16913.11
Exact Fit for your 1988 Jeep Cherokee
Auto Trans Flexplate; Automatic Transmission Flexplate
Summit Racing update information
Summit Racing list his number ATP Automotive part # Z-205 is OK for 87-90 XJ 4.0L
This is the information that I found on line from Advance Auto.
These part numbers don’t match yours.
Advance Auto link for parts below.
https://shop.advanceautoparts.com/we...eIdSearch=8502
CARQUEST New Flywheel
#50-1004
Exact Fit for your 1988 Jeep Cherokee
Clutch Flywheel
Valeo Steel Flywheel
#V2072
Exact Fit for your 1988 Jeep Cherokee
Clutch Flywheel; Flywheel; disc size: 10 3/8 x 1 1/8 x 10
Omix-Ada Automatic Transmission Flexplate
#16913.11
Exact Fit for your 1988 Jeep Cherokee
Auto Trans Flexplate; Automatic Transmission Flexplate
Summit Racing update information
Summit Racing list his number ATP Automotive part # Z-205 is OK for 87-90 XJ 4.0L
Last edited by djgrayxj; 03-07-2018 at 10:40 PM.
03-08-2018, 08:03 AM
#68
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I'm probably mistaken on this and it sounds like he ended up with the correct flex plate anyhow.
03-08-2018, 08:06 AM
#69
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Year: 1990
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Engine: 4.0
Here
05-07-2018, 01:40 AM
#71
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Eliminated all electrical components, pulled timing cover
I checked the flexplate - it is identical to the Renix one in Cruiser's post ( the one marked Renix)
I finally changed the ECM (remanufactured one) to eliminate the last of the electronics that could be causing this - no change, ran exactly the same/
I pulled the timing cover and the valve cover. I had help setting to TDC using timing marks and harmonic balancer mark, distributor was exactly 180-degrees out, so I reindexed to #1 tower.
I again set #1 to TDC by turning the crank as it went through one full cycle - watched exhaust valve open then close, watched the intake valve open then close. Brought to top on compression.
I looked at the timing marks (after setting TDC #1 manually set by observing the valves) - they were 180-degrees off and the distributor rotor was again 180-degrees off as seen in picture that is attached to this post (red arrows pointed at each timing mark in photo).
Any ideas? Outside of my level of knowledge as to what this means and what I need to do to fix it.
I finally changed the ECM (remanufactured one) to eliminate the last of the electronics that could be causing this - no change, ran exactly the same/
I pulled the timing cover and the valve cover. I had help setting to TDC using timing marks and harmonic balancer mark, distributor was exactly 180-degrees out, so I reindexed to #1 tower.
I again set #1 to TDC by turning the crank as it went through one full cycle - watched exhaust valve open then close, watched the intake valve open then close. Brought to top on compression.
I looked at the timing marks (after setting TDC #1 manually set by observing the valves) - they were 180-degrees off and the distributor rotor was again 180-degrees off as seen in picture that is attached to this post (red arrows pointed at each timing mark in photo).
Any ideas? Outside of my level of knowledge as to what this means and what I need to do to fix it.
06-26-2018, 09:23 PM
#72
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Year: 1988
Engine: 4.0L
FIX IT!!!!!!!
Glad to report that after nearly a year - Ellie Mae is back up and running!
Two problems were responsible - for one, the machine shop installed the timing gears one-tooth off. I figured this out after an old friend who used to work at a dealership and now runs his own shop sent me the attached photo of a page from his repair manual. I counted the pins that should have been 15-pins, and counted 16-pins. Another buddy gave me a hand removing and reinstalling the gears and they then passed the 15-pin alignment test with flying colors.
It idled a bit better, but still had the same issue during acceleration.
THE FIX: After some extensive research, I found a thread somewhere in which a guyed talked about similar issues caused by a bad flexplate. The part number he listed was ATP Automotive part# Z-205.
I finally bit the bullet and bought a used OEM flexplate off of a 1990 Wagoneer 4.0, cleaned it up and replaced mine - which was also a ATP Automotive Z-205.
BAM! it's fixed!
I will follow-up this email with photos of the OEM flexplate next to the ATP. It is so close, it's hard to tell whats going on until you see them side-by-side. The large openings are off by about 1/4 inch on one, about 1/2 inch on another and just over 1/2 inch on the third one. You can also see that there are spots where the sensor ring edge is uneven, and there is a ridge on the OEM ring that is not there on the edge of the ATP.
I bought it from Advance Auto - headed back there to get a refund tomorrow (according to their warranty policy, I can either get a replacement or a refund for a factory defective part - I will definitely not be putting any more of that poison in my Ellie Mae, most definitely taking the refund!!!
Thank for all of the help!, since this was the last thing I tried (for obvious reasons - pulling the transmission) , from a mechanical point of view - I basically have a new engine, computer system, sensors and fuel system - top to bottom!
Two problems were responsible - for one, the machine shop installed the timing gears one-tooth off. I figured this out after an old friend who used to work at a dealership and now runs his own shop sent me the attached photo of a page from his repair manual. I counted the pins that should have been 15-pins, and counted 16-pins. Another buddy gave me a hand removing and reinstalling the gears and they then passed the 15-pin alignment test with flying colors.
It idled a bit better, but still had the same issue during acceleration.
THE FIX: After some extensive research, I found a thread somewhere in which a guyed talked about similar issues caused by a bad flexplate. The part number he listed was ATP Automotive part# Z-205.
I finally bit the bullet and bought a used OEM flexplate off of a 1990 Wagoneer 4.0, cleaned it up and replaced mine - which was also a ATP Automotive Z-205.
BAM! it's fixed!
I will follow-up this email with photos of the OEM flexplate next to the ATP. It is so close, it's hard to tell whats going on until you see them side-by-side. The large openings are off by about 1/4 inch on one, about 1/2 inch on another and just over 1/2 inch on the third one. You can also see that there are spots where the sensor ring edge is uneven, and there is a ridge on the OEM ring that is not there on the edge of the ATP.
I bought it from Advance Auto - headed back there to get a refund tomorrow (according to their warranty policy, I can either get a replacement or a refund for a factory defective part - I will definitely not be putting any more of that poison in my Ellie Mae, most definitely taking the refund!!!
Thank for all of the help!, since this was the last thing I tried (for obvious reasons - pulling the transmission) , from a mechanical point of view - I basically have a new engine, computer system, sensors and fuel system - top to bottom!
06-26-2018, 10:57 PM
#73
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Glad to report that after nearly a year - Ellie Mae is back up and running!
Two problems were responsible - for one, the machine shop installed the timing gears one-tooth off. I figured this out after an old friend who used to work at a dealership and now runs his own shop sent me the attached photo of a page from his repair manual. I counted the pins that should have been 15-pins, and counted 16-pins. Another buddy gave me a hand removing and reinstalling the gears and they then passed the 15-pin alignment test with flying colors.
It idled a bit better, but still had the same issue during acceleration.
THE FIX: After some extensive research, I found a thread somewhere in which a guyed talked about similar issues caused by a bad flexplate. The part number he listed was ATP Automotive part# Z-205.
I finally bit the bullet and bought a used OEM flexplate off of a 1990 Wagoneer 4.0, cleaned it up and replaced mine - which was also a ATP Automotive Z-205.
BAM! it's fixed!
I will follow-up this email with photos of the OEM flexplate next to the ATP. It is so close, it's hard to tell whats going on until you see them side-by-side. The large openings are off by about 1/4 inch on one, about 1/2 inch on another and just over 1/2 inch on the third one. You can also see that there are spots where the sensor ring edge is uneven, and there is a ridge on the OEM ring that is not there on the edge of the ATP.
I bought it from Advance Auto - headed back there to get a refund tomorrow (according to their warranty policy, I can either get a replacement or a refund for a factory defective part - I will definitely not be putting any more of that poison in my Ellie Mae, most definitely taking the refund!!!
Thank for all of the help!, since this was the last thing I tried (for obvious reasons - pulling the transmission) , from a mechanical point of view - I basically have a new engine, computer system, sensors and fuel system - top to bottom!
Two problems were responsible - for one, the machine shop installed the timing gears one-tooth off. I figured this out after an old friend who used to work at a dealership and now runs his own shop sent me the attached photo of a page from his repair manual. I counted the pins that should have been 15-pins, and counted 16-pins. Another buddy gave me a hand removing and reinstalling the gears and they then passed the 15-pin alignment test with flying colors.
It idled a bit better, but still had the same issue during acceleration.
THE FIX: After some extensive research, I found a thread somewhere in which a guyed talked about similar issues caused by a bad flexplate. The part number he listed was ATP Automotive part# Z-205.
I finally bit the bullet and bought a used OEM flexplate off of a 1990 Wagoneer 4.0, cleaned it up and replaced mine - which was also a ATP Automotive Z-205.
BAM! it's fixed!
I will follow-up this email with photos of the OEM flexplate next to the ATP. It is so close, it's hard to tell whats going on until you see them side-by-side. The large openings are off by about 1/4 inch on one, about 1/2 inch on another and just over 1/2 inch on the third one. You can also see that there are spots where the sensor ring edge is uneven, and there is a ridge on the OEM ring that is not there on the edge of the ATP.
I bought it from Advance Auto - headed back there to get a refund tomorrow (according to their warranty policy, I can either get a replacement or a refund for a factory defective part - I will definitely not be putting any more of that poison in my Ellie Mae, most definitely taking the refund!!!
Thank for all of the help!, since this was the last thing I tried (for obvious reasons - pulling the transmission) , from a mechanical point of view - I basically have a new engine, computer system, sensors and fuel system - top to bottom!
06-27-2018, 08:13 AM
#74
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Join Date: May 2015
Location: Arizona
Posts: 4,481
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Year: 97
Model: Cherokee
Engine: 4.0
Glad to report that after nearly a year - Ellie Mae is back up and running!
Two problems were responsible - for one, the machine shop installed the timing gears one-tooth off. I figured this out after an old friend who used to work at a dealership and now runs his own shop sent me the attached photo of a page from his repair manual. I counted the pins that should have been 15-pins, and counted 16-pins. Another buddy gave me a hand removing and reinstalling the gears and they then passed the 15-pin alignment test with flying colors.
It idled a bit better, but still had the same issue during acceleration.
THE FIX: After some extensive research, I found a thread somewhere in which a guyed talked about similar issues caused by a bad flexplate. The part number he listed was ATP Automotive part# Z-205.
I finally bit the bullet and bought a used OEM flexplate off of a 1990 Wagoneer 4.0, cleaned it up and replaced mine - which was also a ATP Automotive Z-205.
BAM! it's fixed!
I will follow-up this email with photos of the OEM flexplate next to the ATP. It is so close, it's hard to tell whats going on until you see them side-by-side. The large openings are off by about 1/4 inch on one, about 1/2 inch on another and just over 1/2 inch on the third one. You can also see that there are spots where the sensor ring edge is uneven, and there is a ridge on the OEM ring that is not there on the edge of the ATP.
I bought it from Advance Auto - headed back there to get a refund tomorrow (according to their warranty policy, I can either get a replacement or a refund for a factory defective part - I will definitely not be putting any more of that poison in my Ellie Mae, most definitely taking the refund!!!
Thank for all of the help!, since this was the last thing I tried (for obvious reasons - pulling the transmission) , from a mechanical point of view - I basically have a new engine, computer system, sensors and fuel system - top to bottom!
Two problems were responsible - for one, the machine shop installed the timing gears one-tooth off. I figured this out after an old friend who used to work at a dealership and now runs his own shop sent me the attached photo of a page from his repair manual. I counted the pins that should have been 15-pins, and counted 16-pins. Another buddy gave me a hand removing and reinstalling the gears and they then passed the 15-pin alignment test with flying colors.
It idled a bit better, but still had the same issue during acceleration.
THE FIX: After some extensive research, I found a thread somewhere in which a guyed talked about similar issues caused by a bad flexplate. The part number he listed was ATP Automotive part# Z-205.
I finally bit the bullet and bought a used OEM flexplate off of a 1990 Wagoneer 4.0, cleaned it up and replaced mine - which was also a ATP Automotive Z-205.
BAM! it's fixed!
I will follow-up this email with photos of the OEM flexplate next to the ATP. It is so close, it's hard to tell whats going on until you see them side-by-side. The large openings are off by about 1/4 inch on one, about 1/2 inch on another and just over 1/2 inch on the third one. You can also see that there are spots where the sensor ring edge is uneven, and there is a ridge on the OEM ring that is not there on the edge of the ATP.
I bought it from Advance Auto - headed back there to get a refund tomorrow (according to their warranty policy, I can either get a replacement or a refund for a factory defective part - I will definitely not be putting any more of that poison in my Ellie Mae, most definitely taking the refund!!!
Thank for all of the help!, since this was the last thing I tried (for obvious reasons - pulling the transmission) , from a mechanical point of view - I basically have a new engine, computer system, sensors and fuel system - top to bottom!
Right on! good to hear you got it fixed!
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