89 cherokee injector replacement
I purchased upgraded 4 whole Bosch injectors for my 89 cherokee and it idles rough with a lot of black smoke and soot coming from tail pipe. any suggestions on how to fix?
LMAO.
OP, was it running fine before the upgrade? Are they Bosch 746 injectors? There are plenty of 4-hole Bosch injectors out there with vastly different properties including operating pressure and volume.
I would recommend first, making sure they are the proper injector. If they are Bosch 4-hole injectors for RENIX 4.0L they should each be stamped "280 155 746". Next, while idling, try jiggling the injector harness and each individual plug to see if it affects your idle. If it does, you'll have to narrow down the issue from there but at least you'll be in the right neighborhood.
OP, was it running fine before the upgrade? Are they Bosch 746 injectors? There are plenty of 4-hole Bosch injectors out there with vastly different properties including operating pressure and volume.
I would recommend first, making sure they are the proper injector. If they are Bosch 4-hole injectors for RENIX 4.0L they should each be stamped "280 155 746". Next, while idling, try jiggling the injector harness and each individual plug to see if it affects your idle. If it does, you'll have to narrow down the issue from there but at least you'll be in the right neighborhood.
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Most of us with Renix-era XJs have experienced a leaking injector or two where the plastic cap meets the metal body. Do the jiggle test on the injector harness wiring (along the valve cover) and test each connector. I suspect you've got a bad injector which may be a fault in the delicate and brittle wiring and not necessarily the injector, itself.
U ll be looking for some Easter candy and hear some bells when u jiggle the wires. But if u feel some electric shocks. U ll have to mentally prepare yourself for some wings to grow out of your back and a rainbow coming out of the butt
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Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
had to look to see if i was on pirate.......
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0



