One Shot

1996 Grand Cherokee 4.0 Auto
First attempt: Turns over normal but no start.
Second Attempt: Starts fine..runs fine..all is normal.
Facts: No ck eng light on. Turning key to off-on 3 times gives code of 55 on odometer and also 2 sets of 5 blinks on eng light.

Car will always start second time...never fails. Once I held starter on first time and after 6 seconds it started and chugged like it was flooded or running on 1-2 cyclinders.

Is it true that first attempt the ECU uses data from sensors and tries to set system accordingly. When you try second time the ECU sets engine to DEFAULT settings ? Friend mentioned this.

Strange that no "chk engine" light on. Also the 55 on odometer or the blinks on "ck eng" light during test is proper for "end of code list" from OBD1 system. I read all cars startin 1996 are required to be OBD2. This would not be a proper code for OBD2.

Can it have a code stored but not turn on "ck eng" light. Remember light is workin ok...not burned out. It blinks with 55.

Wow...this is my daughters car she just bought just 2 weeks ago. Already I see the wet carpet on passenger side...thanks to this forum I will be cleaning out the evaporator drain line this weekend. Her first car was a 1987 Cherokee Laredo 4.0 (first year for 4.0) with 5 speed and 158,ooo miles and its doing great still... What a way to start into a new or used vehicle with this Grand Cherokee....

Thanks for any help.
One Shot vls@juno.com

dksob81

Sounds like a bad Fuel Pressure regulator, try this, turn the key to the ON position (furthest forward without cranking engine) for 10 seconds the turn forward a lil more to the start position (starts cranking engine). does the jeep start?
If it does then the Fuel Pressure Regulator is most likely the cause.

JDPascal

welcome to AF One Shot

The 55 code is the end of codes code......

There seems to be some discrepency as to when the OBD codes changed. I have a list with these codes for a 1997 so what gives???

As for your starting problem, the place to start would be a fuel pressure test.. Check for running pressure and leak down with the engine shut off and sitting for an hour or so.... the pressure should hold while the engine is shut off.

JD

JDPascal

HA ya beat me to it DK

Way to go!!!

JD

dksob81

ooo I'm getting quick.....lol

OBD II was required on all vehicle starting in 1996. But jeep still left the CHECK ENGINE flashing for OBD II vehicles as well. I think the reason is they probably weren't sure if theyw ere going to have Digital Odometer for all the newer vehicles or how they were going to set up the DTC Identification. I have the CODES for the OBD I version on OBD II equipped vehicle.

Example:
Code 33 = P0645
Code 27 = P0203, P0202, P 0201
Code 25 = P0505
Code 42 = P1388

there are just a few examples.