2000 Jeep Grand Cherokee Crank No Start

Tiny
JAMESODOM
  • MEMBER
  • 2000 JEEP GRAND CHEROKEE
  • 4.0L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 210,000 MILES
1. Towed to shop due to Crank no Start condition
2. ODB Computer (Autel DS708) Showed NO Code.
3. Vehicle will crank over and sometimes will start and run really rough then die.
4. Most times it will not run at all. It blows compression back through the throttle body
5. It will back fire sometimes.
6. The crank sensor tested good
7. CAM Sensor tested good
8. Map Sensor test good
9. Coolant Sensor Test Good
10. Fire on coil is good
11. Injector pulse is good
12. Fuel pressure is good
13. Checked Timing on the Balancer and it showed good. Removed the Timing cover and checked the chain and it showed good
14. I came to the conclusion that the computer was bad.
a. I ordered a used one from the salvage yard and had it programed
15. I replaced the computer and it did crank and run but had a Miss to the engine
16. ODB Codes showed Coil Misfire problems
17. Tested the Coil and it tested good, Rechecked all sensors again and tested good
18. Figured that the computer from the salvage yard was bad or something
19. Ordered a NEW Reman Computer from All Computer Resources in Miami Florida
a. I have purchase several jeep computers from this company over the years and been very pleased with this company
20. The new computer arrived
a. Computer installed
b. NEW CAM Sensor Installed
c. NEW Crank Sensor Installed
d. NEW Map Sensor installed
e. New Coolant Sensor Installed
f. NEW Plugs installed
g. New Coil Pack Installed
21. Vehicle will crank over but not start still.
a. Looks to be over fueling
b. Bucks really bad like the timing is not correct
c. Pops and backfires out the intake
d. Will not run
22. Put the computer from the salvage yard back in the vehicle and it will run sometimes but really rough like it is not firing on all cylinders. I did get it to run long enough that the exhaust pipe between the catalytic convert and the muffler was glowing red. ( Less than 5min)
a. I am guessing that this was from all the fuel that is dumped into the exhaust system from not starting.

I am now at a LOSS on this vehicle
Do you
have the same problem?
Yes
No
Saturday, December 6th, 2014 AT 4:58 PM

10 Replies

Tiny
WRENCHTECH
  • EXPERT
You need to look at some of these tests a little closer. What was the fuel pressure. Does the pressure hold within 5PSI for 15 minutes after shutting the key off?

When you put the scanner on it, look at data and see if the intake air temp sensor and the coolant temp sensor match before the truck is started.

What do the plugs look like when removed? Are the plugs fuel stained?
Was this
answer
helpful?
Yes
No
Saturday, December 6th, 2014 AT 5:32 PM
Tiny
JAMESODOM
  • MEMBER
The fuel Pressure was at 52psi and no it did not drop any while cranking or after it was shut down. It will hold the pressure for hours.

I will have to check the temp and air sensor when I am back in the shop

The plugs were new but now are black soot looking now. They do smell of fuel though.
Was this
answer
helpful?
Yes
No
Saturday, December 6th, 2014 AT 6:26 PM
Tiny
JAMESODOM
  • MEMBER
There was 2 degrees between the 2 sensors. One was 82 and one was 84
Was this
answer
helpful?
Yes
No
Saturday, December 6th, 2014 AT 7:46 PM
Tiny
WRENCHTECH
  • EXPERT
One more thing to check. Does the fuel pressure drop if the key is left on.

We have pretty much eliminated all sources of extra fuel. We need to check the compression.
Was this
answer
helpful?
Yes
No
Saturday, December 6th, 2014 AT 7:51 PM
Tiny
JAMESODOM
  • MEMBER
No the fuel pressure does not drop.

I did a compression test on it when I first received the vehicle to work on it. They were all good. I just don't remember the numbers. I can do another compression test on it and see what they come out to be.
Was this
answer
helpful?
Yes
No
Saturday, December 6th, 2014 AT 7:54 PM
Tiny
WRENCHTECH
  • EXPERT
I see something goofy in the data. On page 3 the Bank 2 Pulse width is 50. That can't be right.
Was this
answer
helpful?
Yes
No
Saturday, December 6th, 2014 AT 7:57 PM
Tiny
JAMESODOM
  • MEMBER
What could cause this? This data was taken Key on Engine Off.
Was this
answer
helpful?
Yes
No
Saturday, December 6th, 2014 AT 8:00 PM
Tiny
JAMESODOM
  • MEMBER
Also what would be Bank 2 on a Inline 6 Engine?
Was this
answer
helpful?
Yes
No
Saturday, December 6th, 2014 AT 8:16 PM
Tiny
WRENCHTECH
  • EXPERT
I don't know. It doesn't make any sense. Are you sure you have the correct PCM and it's flashed correctly?
Was this
answer
helpful?
Yes
No
Sunday, December 7th, 2014 AT 4:41 AM
Tiny
JAMESODOM
  • MEMBER
The company I ordered it from claims it is the correct one. I have ordered 2 of them and had them programed. I ordered a used one from the salvage yard and had it programed and them I ordered a reman one and it cam programed. Different vendors
Was this
answer
helpful?
Yes
No
Monday, December 8th, 2014 AT 10:22 AM

Please login or register to post a reply.

Recommended Guides