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Unread 08-25-2013, 04:16 PM   #1
reydelaplaya
Registered User
1996 ZJ 
 
Join Date: Nov 2010
Location: Cuatro Esquinas, Puerto Rico
Posts: 159
4.0 ZJ Stalling/Losing power after long drives?

Hey folks! Hope y'all's summertime has been full of fun!

Just hoping to find some ideas as to why my 96 4.0 has been trying to stall after longer drives.

My usual commute is about 1/2 an hour or so, but recently I had to go to the other side of the island to pick up a friend at the airport - a highway drive about 2hrs or so one way. As I was coming back, about an hour and a half into the trip, when I stepped on the gas, the engine attempted to die out a couple times. I was in an area where I could pull off the highway, and did so, in order to give it a rest. After a rest of about 30min or so, it drove perfectly for the duration of the trip.

The next day and the day following, it did the same after running almost an hour for both to and from a trip to the south of the island - about an hour's drive one way.

Instinct and experience tell me it's probably a clogging cat, but there's no CEL, and it's fine after a quick rest.

Most recent tune up was less than 2 yrs ago. Plugs/wires/rotor/cap/air filter/fuel filter/etc. were all changed, have been checked, and are all in great condition.

For my local drives, including my drive to and from work it's fine, with no loss of power whatsoever.

Temp's normal, oil pressure and voltage, too. Nothing to suggest a problem.

You guys got any ideas?

Thanks,

Rey


Last edited by reydelaplaya; 08-25-2013 at 04:25 PM.. Reason: Clarification
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Unread 08-25-2013, 06:39 PM   #2
ZeeJay1997
Registered User
1997 ZJ 
 
Join Date: Dec 2008
Location: Sweet Home, Alabama
Posts: 6,176
Quote:
Originally Posted by reydelaplaya View Post
when I stepped on the gas, the engine attempted to die out a couple times.

Instinct and experience tell me it's probably a clogging cat, but there's no CEL, and it's fine after a quick rest.
the bogging down when you step on it may be a clogged cat. if the engine temp rises slightly when this occurs, it's even more suspect. do the key trick and check for stored codes. some codes may not turn the light on, including misfire codes.

Your coil is also suspect. take it out and check for cracks and arcing.
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Unread 08-25-2013, 10:28 PM   #3
reydelaplaya
Registered User
1996 ZJ 
 
Join Date: Nov 2010
Location: Cuatro Esquinas, Puerto Rico
Posts: 159
Quote:
Originally Posted by ZeeJay1997 View Post
the bogging down when you step on it may be a clogged cat. if the engine temp rises slightly when this occurs, it's even more suspect. do the key trick and check for stored codes. some codes may not turn the light on, including misfire codes.

Your coil is also suspect. take it out and check for cracks and arcing.
Thank you for the tips! I'll start there when I get home from work tomorrow and see where it leads me.

Thanks again!

I'll post results when I have 'em.
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