just got an 88 4.0 andf need to know what
Thread Starter
Newbie
Joined: Jul 2012
Posts: 19
Likes: 0
From: lone pine ca
Year: 88 cherokee
Model: Cherokee
Engine: 4.0
are the most common problems with these motors .i am putting in a new head gasket (but it doesnt look like it blew )i do have 2 plugs that look like they arent firing very well 3,6 . do the inhjectors go bad like in my old zr1s due to the new fuel breaching the coil sealing?? they all ohm put at 16.5. it looks like there is alot of black gunk in the intake passages . can one get trouble codes from these motors . any guidance would be greatly appreciated . as this is the wifes new toy and is on my buns to get it going .
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
The crap stock injectors on those is are a fire hazard as well.
I'm having second thoughts on have gone with the703's. Fine for allot of people I suppose. My issue is I make allot of short trips. Complicated, but the way the computer uses default settings I might be running rich allot.
In my signature, you might be especially interested in the C-101 connector, and the ground cleanup deal Cruiser wrote..
I'm having second thoughts on have gone with the703's. Fine for allot of people I suppose. My issue is I make allot of short trips. Complicated, but the way the computer uses default settings I might be running rich allot.
In my signature, you might be especially interested in the C-101 connector, and the ground cleanup deal Cruiser wrote..
Senior Member
Joined: Aug 2011
Posts: 604
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From: California
Year: 1990
Model: Cherokee
Engine: 4.0 i6
Originally Posted by Gee oh Dee
I didnt know 703s were the right injectors for the Renix models.
I thought they were different than the 703s because of the different flow rate of the Renix...
I thought they were different than the 703s because of the different flow rate of the Renix...
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CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
BUT, I've been thinking, in open loop, before temp is reached, and it brings in the 02 sensor in, in closed loop, it's using the default pulse width with the higher flow rate...presto, your rich. I'm mean I'm wondering...seems to make sense to me. Then to exaborate things a little bit, it may well warm up a little more slowly being rich like that.
cherokeelaredo'90..Rockauto sells the (dreaded) Airtex, 4 hole 18.6 lb injectors. At least one poster returned his set when one didn't work. Then Precision Injectors offers ..stuff. Then Programbo here, I was thinking about contacting.
Renix...Renault + Bendix
Last edited by DFlintstone; Jul 12, 2012 at 02:46 PM.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Seasoned Member
Joined: Jan 2011
Posts: 303
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From: Austin
Year: 1987
Model: Wagoneer
Engine: 4.0
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Well, Flintstone, why don't you give the new member a prioritized list of things to do to his Renix Jeep in order to wring the most reliability out of it? Preventative stuff that could be in your signature. I'm curious to see how you prioritize it.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Because YOU are the pro with all those years on the floor at the dealership, and I don't think I've even SEEN a running 88! But hey, the C-101 and grounds gotta be about at the top?
(Under the hood I mean)
(Under the hood I mean)
the most common problems with these motors
Expect some piston slap and lifter noise, both harmless.
The biggest problems seem to be overheating due to an old/neglected/worn out cooling system, wiring issues related to deteriorated grounds and harness wiring, and sensors failing as they age. Typical older vehicle stuff.
Invest in a nice digital multimeter if you don't already have one. It'll come in handy.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I want you to take my write-up list and prioritize it or just prioritize a section we would call "So you got yourself a Renix Jeep..." for new owners.


