91 Cherokee no start?
#1
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Year: 1999
Model: Cherokee
Engine: 4.0
91 Cherokee no start?
I am considering buying another Cherokee as a project vehicle. It's a 91 cherokee 4x4 with the 4.0. The current owner blew the engine out and purchased a replacement 4.0 HO motor out of a 96 cherokee and dropped in the jeep, which will now not start. He claims that it's because the HO requires a higher-flow fuel pump. Is there any truth in this?
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Year: 2001
Model: Cherokee (XJ)
Engine: 4.0L I6 Power Tech
I am considering buying another Cherokee as a project vehicle. It's a 91 cherokee 4x4 with the 4.0. The current owner blew the engine out and purchased a replacement 4.0 HO motor out of a 96 cherokee and dropped in the jeep, which will now not start. He claims that it's because the HO requires a higher-flow fuel pump. Is there any truth in this?
Maybe some else can elaborate, I just don't know about the specifics.
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Year: 1999
Model: Cherokee
Engine: 4.0
I believe that the 96 requires 49 psi of pressure, and the 91 requires 31.
So job #1 is to get a fuel pressure gauge and verify what pressure you have at the rail.
You'll need about 49, plus or minus 5 for it to fire.
So job #1 is to get a fuel pressure gauge and verify what pressure you have at the rail.
You'll need about 49, plus or minus 5 for it to fire.
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Year: 1999
Model: Cherokee
Engine: 4.0
Alright, I looked up the wikipedia articles on the XJ and I see where the 91-95 models had an HO motor as well, but in 96 they switched to a "Chrysler Block Cast" version of the 4.0 HO. Would this cause the kind of pressure issues that tjwalker was talking about? And would the OBD1/OBD2 switch cause the jeep not to start? And if that is the case how would you remedy that situation.
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Year: 1999
Model: Cherokee
Engine: 4.0
Just confirm the fuel pressure spec of 49 and if that is correct and you aren't there, that is your problem.
96 was kind of a hybrid year for fuel delivery. But I'm 99.9% confident that you MUST have 49 psi.
So you'll need the fuel pump system that gets you there.
96 was kind of a hybrid year for fuel delivery. But I'm 99.9% confident that you MUST have 49 psi.
So you'll need the fuel pump system that gets you there.
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