Sluggish Acceleration

macleanflood said:
A brand new AX-15 from Novak or Advanced Adapters is just under $2k. You'd probably need to find another 231J or research the shaft lengths.

I essentially did a 2.4 swap when I rebuilt my 97 in eight days.

It's an option...

-Mac
Click to expand...

Are you able to cut off the 2.4 mounts and reuse them?

The engineer in me wants to figure out and fix the problem but at the same time depending on what’s wrong cutting my losses and upgrading might make more sense.
 
Duner said:
Are you able to cut off the 2.4 mounts and reuse them?
Click to expand...

Technically speaking I can't answer that...I cut off and discarded the 2.4 mounts and transfered over the 4.0 mounts from my bent frame. The welds are shitty and easy to cut.

I also had to mess with my steering mid shaft mount...the 2.4 brackets land right at the mount and the 4.0 is set almost a foot farther forward.

-Mac
 
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macleanflood said:
Technically speaking I can't answer that...I cut off and discarded the 2.4 mounts and transfered over the 4.0 mounts from my bent frame. The welds are shitty and easy to cut.

I also had to mess with my steering mid shaft mount...the 2.4 brackets land right at the mount and the 4.0 is set almost a foot farther forward.

-Mac
Click to expand...

Do I need the intake to be on during the compression test?
 
valve pictures, in cylinder order 1-2-3-4

C26C81CF-ECDF-4C33-B541-BDE5A5C09F9B.png


0B27D93B-90C0-49E9-8297-AF1248B750B2.png


ECA18AE4-59DC-4F6F-A17E-E159829E6DA6.png


E3A79214-27CB-41D4-BD40-2FFEA062B51E.png


C403C03F-66CC-44EB-A4DB-DA144DC0EAC8.png


5496BBC2-F92F-49F5-A78D-3A76A0AAB1A0.png


D991BB07-EF1B-4A3A-8510-E209C13DDAF4.png


03EB5D3F-214E-4CE2-AB6E-F17BE8088ECF.png
 
They look cleaner than mine...but it's the seats that count... compression test/leakdown test will help answer some of those questions.

-Mac
 
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@CharlesHS @macleanflood @JKP @Artsifrtsi

Just got back from a long weekend out of town and did my compression testing. Two compression readings per cylinder. Here are the results.

Dry Test:

1: 150/150
2: 172/172
3: 170/170
4:180/180

Since cylinder 1 was an outlier so I did a wet test on it.

Wet Test:

1: 170/170

Since the wet test enhanced the PSI up to where the other cylinders were, I’m going to assume my issue is the rings on cylinder 1 are bad right?
 
Duner said:
@CharlesHS @macleanflood @JKP @Artsifrtsi

Just got back from a long weekend out of town and did my compression testing. Two compression readings per cylinder. Here are the results.

Dry Test:

1: 150/150
2: 172/172
3: 170/170
4:180/180

Since cylinder 1 was an outlier so I did a wet test on it.

Wet Test:

1: 170/170

Since the wet test enhanced the PSI up to where the other cylinders were, I’m going to assume my issue is the rings on cylinder 1 are bad right?
Click to expand...

Did you just do a compression test or a leak down test ?
The leak down test would tell you if the exhaust or intake valve was leaking by....
Not necessarily bad, but the compression ring is not working as well as on the other three cylinders.
 
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CharlesHS said:
Did you just do a compression test or a leak down test ?
The leak down test would tell you if the exhaust or intake valve was leaking by....
Not necessarily bad, but the compression ring is not working as well as on the other three cylinders.
Click to expand...

Just the compression test for now. No local shops have kits I can rent/borrow so I’m waiting for the leak down kit to come in.
 
Update:

Decided to run the compression test again today just to double check. I did a wet test for them all and surprisingly everything was close this time.

1: 190/190
2: 195/195
3: 195/195
4: 205/205

Still waiting on my leak down kit but I thought this was interesting.
 
CharlesHS said:
Did you just do a compression test or a leak down test ?
The leak down test would tell you if the exhaust or intake valve was leaking by....
Not necessarily bad, but the compression ring is not working as well as on the other three cylinders.
Click to expand...

Well I think I found my problem during the leak down test…

 
Pull the head. At a minimum lap the valve and replace the seals.

Alternatively go nuclear and have a machine shop go through the head...fair warning that could take months and no guarantees these days anyone does a quality job.

You could also purchase a Clearwater head.

I'd lap the valves and change the seals. New seals come with a Felpro head gasket kit anyways.

-Mac
 
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@CharlesHS @macleanflood

Thank you for all the help guys! I’m mechanically inclined but I’ve never gone this far down the rabbit hole, so I appreciate all the tips.

I do have an extra head from a blown motor… maybe I could use that or just say screw it and get a new one
 
Duner said:
@CharlesHS @macleanflood

I do have an extra head from a blown motor… maybe I could use that or just say screw it and get a new one
Click to expand...

Machine shops use a tool to check valve leakage before assembly.

You don't have that tool...so you either would need to engage a shop that does on that used head...or stick with the one you know exactly where the problem is.

My guess is you can fix this problem with a $115 head gasket kit and $5 in valve lapping compound.

-Mac
 
Last edited:
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macleanflood said:
Machine shops use a tool to check valve leakage before assembly.

You don't have that tool...so you either would need to engage a shop that does on that used head...or stick with the one you know exactly where the problem is.

My guess is you can fix this problem with a $115 head gasket kit and $5 in valve lapping compound.

https://www.amazon.com/Fel-Pro-HS9076PT4-Head-Gasket-Set/dp/B0016ZIZUK?tag=wranglerorg-20

-Mac
Click to expand...

Just for documentation/ to avoid confusion for others that may follow this thread, I found the correct fel-pro kit on Amazon since mine is a 2.4L

FEL-PRO Head Gasket HS26206PT-1​


Your link still helped me get to the right spot. Thanks!
 
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macleanflood said:
Removed my link and thanks for catching that!

-Mac
Click to expand...

@CharlesHS

So I decided to do some more testing just to double check the problematic valves and I found something interesting.

When cylinder 3 was at top dead center (TDC), there was no leakage. I then rotated 360 degrees for the second TDC position during the combustion cycle, and this time both the intake and exhaust valves were leaking!

Does this suggest the issue isn’t limited to valves? Let me know.
 
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