1990 Renix 4.0 Floods/Backfires
#1
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Year: 1990
Model: Cherokee
Engine: 4.0
1990 Renix 4.0 Floods/Backfires
1990 Cherokee, auto 4.0 It starts when cold and drives. Will restart immediately but if let it sit for awhile it seems to flood/reeks of fuel and won't start and will backfire. Let it sit long enough it will start normally and be fine. I have done the following since buying it none running- CPS, Map Sensor, O2 Sensor, IAC solenoid, Cap,Plugs,Rotor Wires, Air and Fuel Filter, Starter, Ignition Switch, Refreshed Grounds and Added extra ground straps, Cleaned Throttle body and Air Intake Temp Sensor, B Latch, Fuel, and O2 Heat Relays. Any ideas would be greatly appreciated...
#2
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Leaky injectors can cause your problem. as in you shut it off but the injectors don't all close. Floods the engine. Wait long enough and the fuel evaporates and it starts. Usually with a long crank time.
I suggest replacing those crappy injectors with teh later style 4 hole types for a coupla reasons. One is they don't leak at the seams unexpectedly like yours do and the other is it will probably solve your problem.
I suggest replacing those crappy injectors with teh later style 4 hole types for a coupla reasons. One is they don't leak at the seams unexpectedly like yours do and the other is it will probably solve your problem.
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Year: 1990
Model: Cherokee
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How can you get the four hole injectors? The precisionautoinjectors.com website only shows four hole injectors for 99 and up jeeps, they look much longer then the orginal Siemen injectors. Is there a way to get the better injectors in a Renix motor?
Last edited by nate5022; 11-11-2012 at 06:57 AM.
#6
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Year: 1990
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www.precisionautoinjectors.com can help you also.
#7
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Ok thanks. I was also looking at New Lucas Injectors i found at Five-0 Motorsports....
http://www.fiveomotorsport.com/fuel-.../jeep/?v=18020
http://www.fiveomotorsport.com/fuel-.../jeep/?v=18020
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#8
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Year: 1990
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Ok thanks. I was also looking at New Lucas Injectors i found at Five-0 Motorsports....
http://www.fiveomotorsport.com/fuel-.../jeep/?v=18020
http://www.fiveomotorsport.com/fuel-.../jeep/?v=18020
#9
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#10
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Year: 1990
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#12
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Year: 1990
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Engine: 4.0
Too much fuel still...
Replaced the injectors and fuel pressure regulator. Still wouldnt start. Took out a plug and laid it on the valve cover. It sparked when cranked. While cranking fuel ran out the empty hole and appeared the engine was flooding out. Ohmed out the air and coolant temp sensors. Coolant temp sensor was way high for the temps so I replaced it. But still doing the same thing. The Map sensor and o2 sensor are new.. What else could be the problem causing it to dump too much fuel?
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Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Replaced the injectors and fuel pressure regulator. Still wouldnt start. Took out a plug and laid it on the valve cover. It sparked when cranked. While cranking fuel ran out the empty hole and appeared the engine was flooding out. Ohmed out the air and coolant temp sensors. Coolant temp sensor was way high for the temps so I replaced it. But still doing the same thing. The Map sensor and o2 sensor are new.. What else could be the problem causing it to dump too much fuel?