Last post on May 11, 2013 at 8:28 AM
You are in the Jeep Cherokee and Jeep Grand Cherokee
What is this discussion about?
Jeep Cherokee, Transmission, SUV
#256 of 275 Re: Ignition we on 2001 Cherokee Sport [cski]
Oct 27, 2011 (3:53 pm)
Thank you for your reply. I have a question if you don't mind. What is a Engine Control Unit? I that the computer it self and where is it located?
#257 of 275 ECU function, location, and price
Oct 28, 2011 (5:01 am)
The ECU is the Engine Control Unit. It controls the air/fuel mixture during all operating modes and adjusts for air temperature, engine load, engine speed, throttle position, fuel octane, and on and on. Works with all the sensors on the car, and almost instantaneously adjusts for the best power and fuel economy.
If it needs to be replaced, go to www.autocomputerexchange.net. They have every computer there is, and I already checked it for you. $199 gets u a new one, and after you supply them with your vin# and mileage, it gets all the software and updates from Jeep before you even get it, and just plugs in. It is either in the engine bay, or under the passenger side of the cabin. If your Jeep is running poorly, take it to the nearest shop and get the codes from the ECU, then they can tell you if the problem is computer, sensor, or hardware issue. Good luck.
#258 of 275 Grand Cherokee Start up issue
Nov 02, 2011 (1:47 pm)
I have a 2004 GC w/ 135K on it. I started having a problem with startup. It wouldn't start on the first go round but if i cranked it 4 - 5 seconds and turned it off and then cranked it, it would start fine. So we replaced the fuel filter thinking it was the check valve not holding pressure. 2 months later, same thing. So some sensors came up on the diagnostics, we replaced those, and same problem. So we replaced the new fuel pump with a newer fuel pump. Same problem and no engine light on. Either the new fuel pump is defective or some thing else is happening.
Mechanics and I don't know. Mechanic wants to change the timing gears.
#259 of 275 Re: Grand Cherokee Start up issue [billg10549]
Nov 08, 2011 (8:41 pm)
i have a 2000 jeep grand cherokee laredo its a 4.0 and i have the same problem when i start it the idle drops a little below the 1000 rpms it only happens when im at a stop sign i checked the coil plugs and it has good spark the next thing to check is the injectors i checked the codes it it said cylinder 1 if any one has this problem or experienced something similar please let me know thx
#260 of 275 Re: Grand Cherokee Start up issue [00jeeplaredo]
Nov 11, 2011 (9:35 am)
Changed the after market fuel pump 2x and now are trying a Chrysler pump. Changed a few sensors and checked the injectors. The symptoms all point to the fuel pump check valve so we will know later.
Also the mileage according to the display is all over the place but not where it should be. The guys at the shop have been good with all of this and are not charging me for the extra time involved.
#261 of 275 Re: Grand Cherokee Start up issue [00jeeplaredo]
Nov 16, 2011 (6:42 pm)
the coolant tempature sensor will do this. it cost about $20.00 and takes 2minutes to put on. It tells the computer how much fuel to give the engine based on temp.
#262 of 275 Re: Grand Cherokee Start up issue [yort1]
Nov 17, 2011 (7:04 am)
Put in a Chrysler fuel pump and it is working fine. I will remember the coolant sensor for the future but that did not come up as a problem on the computer
#263 of 275 Re: Grand Cherokee Start up issue [billg10549]
Nov 17, 2011 (1:44 pm)
recently its been hesitating when i get on the highway at around 50mph it starts to sputter anybody has had a similar problem??? and its still has the rough idle motor seems to shake a bit at idle