96 Grand Cherokee problems

itbrokeagain · 05-11-2008, 05:07 PM

Told a friend I would try to find out what is wrong with her jeep.

96 Grand Cherokee, 4.0, auto, 150,000 miles.

She says when she gives it gas it bogs down real bad. She also said it started out doing this only on take off and now it does it on take off and at all speeds.

Any ideas?

carwash · 05-11-2008, 09:45 PM

MAF or EGR

94Dodge Truggy · 05-11-2008, 11:11 PM

check engine light? Scan it and see what it pulls up. Could also be the catalytic converter if it is not a sensor.

jfiscus · 05-12-2008, 09:06 AM

My 97 does this at take off after sitting. Would like to know what it is too. After it does it once it's fine?

94Dodge Truggy · 05-12-2008, 09:26 AM

I think it is a tps sensor or catalytic converter.

blazerbrad · 05-12-2008, 09:28 AM

Pulling any codes would be the first thing I would do. Another quick check is to pull the air intake off and see if you have any oil in it. It seems fairly common for the PCV to fail and allow engine oil to get sucked into the air intake which can cause issues.

Look at the obvious things first before you start throwing parts ($$) at it blindly. Look for corrosion, gunk buildup, loose connections or shorted wires at the sensors (TPS, MAF/MAS, O2, etc...). A bad (clogged) catalystic converter can be checked by either removing the upstream O2 sensor or opening up a connection ahead of the converter and see if the driveability issue improves or not (though the newer converters, by design, rarely actually clog up the exhaust when the fail), though I have seen them damage the O2 sensors...but that should throw a code.

The next step would be to try to get ahold of a diagnostic manual. The factory ones usually have a whole list of "if it does this...go through this diagnostic tree" which usually will point you in the right direction. Sometimes a dealer will let you go in and look this up and make copies, or if you have any other source (buddy who is a tech at a dealership).

If I have a chance I will try to look this up as I have access to a lot of these manuals, but not sure if I have that exact one or not.

itbrokeagain · 05-14-2008, 07:26 PM

Found it. The only reason I found it is the fuel pump just went out yesterday. Changed it and it is fine.

05-11-2008, 05:07 PM	#1
itbrokeagain Just Empty Every Pocket - CORE Member - Join Date: Feb 2007 Location: Amelia Posts: 1,435	96 Grand Cherokee problems Told a friend I would try to find out what is wrong with her jeep. 96 Grand Cherokee, 4.0, auto, 150,000 miles. She says when she gives it gas it bogs down real bad. She also said it started out doing this only on take off and now it does it on take off and at all speeds. Any ideas? __________________ 91 fj 80 on 37 Nitto Muds with a 10k winch. Cage and sliders coming soon.

05-11-2008, 09:45 PM	#2
carwash pimpin' IS easy Join Date: Jan 2007 Location: Union, KY Posts: 3,344 Images: 605	MAF or EGR __________________

05-11-2008, 11:11 PM	#3
94Dodge Truggy EX-Vice President Join Date: Jan 2007 Location: Fairfield, Ohio Posts: 3,048	check engine light? Scan it and see what it pulls up. Could also be the catalytic converter if it is not a sensor. __________________

05-12-2008, 09:26 AM	#5
94Dodge Truggy EX-Vice President Join Date: Jan 2007 Location: Fairfield, Ohio Posts: 3,048	I think it is a tps sensor or catalytic converter. __________________

05-14-2008, 07:26 PM	#7
itbrokeagain Just Empty Every Pocket - CORE Member - Join Date: Feb 2007 Location: Amelia Posts: 1,435	Found it. The only reason I found it is the fuel pump just went out yesterday. Changed it and it is fine. __________________ 91 fj 80 on 37 Nitto Muds with a 10k winch. Cage and sliders coming soon.

05-12-2008, 09:06 AM	#4
jfiscus Terrain Stomper Join Date: Feb 2007 Location: Crittenden, KY Posts: 633	My 97 does this at take off after sitting. Would like to know what it is too. After it does it once it's fine?

05-12-2008, 09:28 AM	#6
blazerbrad - CORE Member - Join Date: Feb 2007 Posts: 831 Images: 6	Pulling any codes would be the first thing I would do. Another quick check is to pull the air intake off and see if you have any oil in it. It seems fairly common for the PCV to fail and allow engine oil to get sucked into the air intake which can cause issues. Look at the obvious things first before you start throwing parts ($$) at it blindly. Look for corrosion, gunk buildup, loose connections or shorted wires at the sensors (TPS, MAF/MAS, O2, etc...). A bad (clogged) catalystic converter can be checked by either removing the upstream O2 sensor or opening up a connection ahead of the converter and see if the driveability issue improves or not (though the newer converters, by design, rarely actually clog up the exhaust when the fail), though I have seen them damage the O2 sensors...but that should throw a code. The next step would be to try to get ahold of a diagnostic manual. The factory ones usually have a whole list of "if it does this...go through this diagnostic tree" which usually will point you in the right direction. Sometimes a dealer will let you go in and look this up and make copies, or if you have any other source (buddy who is a tech at a dealership). If I have a chance I will try to look this up as I have access to a lot of these manuals, but not sure if I have that exact one or not.