Hey everybody, I want to pick some brains on what is causing a problem for a friends Jeep. First off it is a 1993 Jeep Grand Cherokee with the 5.2L. What seems to be happening is his injectors are not firing. The vehicle has spark and I can keep it running by dribbling gas down the throttle body. I have checked for fuel pressure and I have 42 lbs at the rail. Does anyone have an idea of where I could start looking or what would kick the injectors to work. I am thinking of renting a node tester and just seeing if the injectors have pulse or not. Thanks for the help in advance.

Ok I have an update on the Jeep, I rented the node tester and sure enough no pulse. So now I don't know where to look next. The next thing is the electric locks do not work on the vehicle either does any one know if the stock alarms on these Jeeps lock out the vehicle from running? 

have seen thiss one at least 5 times change the ecu is toast commen jeep problem the injector drivers go out

have seen thiss one at least 5 times change the ecu is toast commen jeep problem the injector drivers go out

Hey Ivan, do you know anything about the renix systems jeeps?

 

Sorry for the hijack o.p.

Ivan, thank you I will try that today. I found 3 ECU over at my local yard. I was thinking of going that direction but I also found that the security system could cause this same issue and with the doors locks and security not working I would change that out first.

OK Good news I took Ivans advice and picked up a ECU out at the yard and put it in and the Jeep started right up. Thaank you for your help.

I work on just subarus but have put in 15 years of work on everything under the sun jeeps hang with subarus hand in hand. I had been thru the try the alarm module try the ig module try the power control mod just to find bad ecu in the end. I bet it took me longer to find it the first time by the 5th one fixed in ten munites. The renix sestem you refer to i dont know what you mean ?

Renix is the system pre OBDI on the early fuel injected 4.0l AMC jeeps, I'm trying to figure out why the fuel injectors cut out randomly, I'm just having a hard time finding people that know about the renix system. I'll start a new thread and let the original subject continue. Sorry o.p. for the hijack.

i think its bosch sestem check dis module or injectors sticking also look for shody wireing conectors grounds ect and mabee ecu have not realy seen any problems with the older ones just newer ones

i think its bosch sestem check dis module or injectors sticking also look for shody wireing conectors grounds ect and mabee ecu have not realy seen any problems with the older ones just newer ones

I'll take a look in those areas and start a new thread on the subject if I'm still having problems, thanks Ivan.