1999 WJ pops thru Throttle body won't start - Jeep Garage - Jeep Forum

Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WJ > Troubleshooting/Problems

Reply
 
Thread Tools Display Modes
 
  #1  
Old 12-30-2015, 04:06 PM
Member
 
Join Date: Dec 2015
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 561
dobrosailor is on a distinguished road
1999 WJ pops thru Throttle body won't start

This has been a long road with this WJ. Bought it as a pig in a poke - dirt cheap, very nice car - 110k miles but won't start. tries to start but flames into intake and stops forward motion on starter motor when it tries to start. Like the timing is too advanced. So far:

Today:

Pumped 5 gallons of old gas out the fuel rail. Put clean gas in and pumped till it was clear coming out the rail.
Cleaned ground strap to valve cover and anchor points

Yesterday:

Measured Fuel Pressure - 45 key on, bumped to 50 during cranking
Replaced Cam sensor with junk yard sensor
Replaced MAP sensor with Junk yard sensor
Tested THrottle Position Sensor - .8V at idle, 4 V at WOT, smooth linear operation through open and close
PUlled all connections and cleaned to PCM
checked ohms between positive battery and power at relay module - power good

Recap past:

New Idle solenoid
New Coil Pack
Compression ~160PSI all cylinders
New Cam Sensor aftermarket
New Crank Position Sensor aftermarket
Replaced new Crank Position Sensor with Junkyard MOPAR sensor
Battery strong, tried jump starting with other car running to increase voltage
Checked wiring harness at rear of valve cover for damage
Pulled all relays and replaced to clean contacts
Video taped Coil while cranking and viewed in slow motion, PCM definitely sending signals to all 6 cylinders, firing 3-4,1-5,1-6.
cleaned all grounds I could find on passenger inner fender and passenger side of block
Cleaned throttle body
New plugs

Any ideas??? Everything tried made absolutely no difference, tries to start but when a cylinder fires it slows the starter down occasionally almost to a stop and occasionally fires through throttle body.

Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old 12-30-2015, 04:56 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,616
Thanks: 23
Thanked 424 Times in 409 Posts
Rep Power: 529939
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: 1999 WJ pops thru Throttle body won't start

Welcome to the garage.
Did you already check the timing? A too far stretched chain can bring the timing off too far.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
The Following User Says Thank You to Frango100 For This Useful Post:
  #3  
Old 12-30-2015, 05:35 PM
Member
 
Join Date: Dec 2015
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 561
dobrosailor is on a distinguished road
Re: 1999 WJ pops thru Throttle body won't start

Wow, did not think to check valve timing. With 110k I would think it would a long shot but as you can see, I'm down to long shots here. I read another post of yours I am going to look at the PCM to see if the case is rusted or damaged in any way. I was thinking about pulling the valve cover anyway, hopefully I can check the timing while its off without getting any deeper e.g. pulling the timing cover.
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old 12-31-2015, 11:24 AM
Member
 
Join Date: Dec 2015
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 561
dobrosailor is on a distinguished road
Re: 1999 WJ pops thru Throttle body won't start

Well I really screwed the pooch this time. I pulled the PCM because it was pretty corroded outside. Wanted to see if the corrosion went inside the PCM causing my problems. Of course I used a screw driver expecting a circuit board in the center. Screwed up some of the traces on the flex circuit all around the PCM. Now I have to deal with the SKIM i believe, I have the grey key that's about 3/8" thick.

Please advise, I can get a PCM from the junk yard, there is 4 from 1999 to 2003, but they probably wont work without involving the dealership right?

Headed for a beer...
Reply With Quote
  #5  
Old 12-31-2015, 01:19 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,616
Thanks: 23
Thanked 424 Times in 409 Posts
Rep Power: 529939
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: 1999 WJ pops thru Throttle body won't start

A cold beer is a good idea, i have one next to me now, but its around 30C (86 F)overhere.
The PCM will need to be programmed with the SKIM secret code, otherwise the engine will start, but shut down after a few seconds.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
  #6  
Old 01-01-2016, 07:06 AM
Member
 
Join Date: Dec 2015
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 561
dobrosailor is on a distinguished road
Re: 1999 WJ pops thru Throttle body won't start

Well, I spent some quality time with my PCM and discovered that the corrosion I saw outside propogated into the PCM under the circuit. I'm hoping that this is the problem I was having, just wondering the best way to approach a new PCM. I have read about remanufactured PCMs supposed to be plug n play. Also heard they can be a crap shoot. I can get one at the junk yard but who knows although they are only $30.

Any thoughts?
Reply With Quote
  #7  
Old 01-01-2016, 05:46 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,616
Thanks: 23
Thanked 424 Times in 409 Posts
Rep Power: 529939
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: 1999 WJ pops thru Throttle body won't start

A happy new year to you.
When it was me, i would have a look at the junk yard PCM first. If its completely free from corrosion, i would go that way and have it programmed by a stealer or any other who has a DRBIII scanner.
You can get a refurbished one, and they will program it for you before sending it, i only wonder how they get the SKIM code, or maybe do a SKIM code delete.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
  #8  
Old 01-04-2016, 03:03 PM
Member
 
Join Date: Dec 2015
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 561
dobrosailor is on a distinguished road
Re: 1999 WJ pops thru Throttle body won't start

Purchased a PCM through FS1 on EBAY. $151 no core, lifetime one time replacement. Nice folks, agreed to send me a photo of the candidate PCM so I can insure that it has no corrosion on the outside of the case - let me approve the PCM. HOpe it works!!!

M
Reply With Quote
  #9  
Old 01-11-2016, 03:03 PM
Member
 
Join Date: Dec 2015
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 561
dobrosailor is on a distinguished road
Re: 1999 WJ pops thru Throttle body won't start

Well i put in the new brain and exact same problem. I'm out of ideas completely. Anything? Think its worth taking to jeep for a read or is that a waste of time? I would have to have it towed likely both ways.
Reply With Quote
  #10  
Old 01-12-2016, 05:41 PM
Member
 
Join Date: Dec 2015
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 561
dobrosailor is on a distinguished road
Re: 1999 WJ pops thru Throttle body won't start

A friend loaned me a good OBD II scanner. I took some live data, wondering if anyone can see anything significant in these, this is from the last of 6 frames, this was done while cranking the motor over, it was flaming the fuel in the intake which is why the intake sensor got hotter I believe:

No DTCs Diagonistic Trouble codes
Fuel Sys 1 status: --
Fuel Sys 2 status: --
Calculated load value: 3.1
Engine Coolant temp F: 24 (cold as hell here)
SHort term fuel trim bank 1: 0.0
Long term fuel trim bank 2: 0.0
INtake manifold pressure: 13.8 PSI
RPM: 304
Spark advance: 0.0
Intake air temp degrees F: 156 - steadly increased from 76 to 156 over six frames, went back out and tested cold - read 30
Throttle positino sensor : from 16.9 to 79 % when I pushed the throttle
Short term fuel trim bank 1 sensor: 0.0
Reply With Quote
  #11  
Old 01-12-2016, 08:08 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,616
Thanks: 23
Thanked 424 Times in 409 Posts
Rep Power: 529939
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: 1999 WJ pops thru Throttle body won't start

Did you check the timing?
Reply With Quote
  #12  
Old 01-20-2016, 05:37 AM
Member
 
Join Date: Dec 2015
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 561
dobrosailor is on a distinguished road
Re: 1999 WJ pops thru Throttle body won't start

Well I took it to the auto mechanic and he was convinced that the timing was off so he reset the cam timing and said that everything was in sink now and I look pretty good. They wanted $100 to put in a set of spark plugs which they said I would get it running. So I took it home put in a service spark plugs and it's definitely better but it still doing the same thing. They agreed that the timing chain probably hasn't slept since they've never seen it happen in a car with this few miles and it probably would affect the compression.

Does anyone know if there's a way to check if the flywheel is broken. I read somewhere in the mechanics also said that sometimes the flywheels crack around the center and then get jammed so that they still work but the timing is off. Just wondering if there's a way to check that
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
HELP PLEASE!! Jeep sputters and pops unless floored dpettit Cherokee-SJ and XJ 11 01-16-2016 02:49 AM
Harman/Kardon pops when using USB and Iphone tjyates08 Audio/Visual/Navigation 6 10-11-2014 10:19 AM
2014 SRT dipstick pops out... cyanideg Grand Cherokee SRT - WK2 5 02-06-2014 06:39 PM
Backlash on throttle on/throttle off and cold start shivering ZF1FR Export & Diesel Powered Jeep Models 8 10-21-2011 07:58 PM
pops got mods on the vette teekay1 Other Rides 22 03-30-2011 09:30 AM

» Premium Vendor Showcase
Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 08:54 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community

JeepGarage.org is in no way associated with or endorsed by FCA US LLC. Chrysler, Dodge, Jeep, Ram, Mopar and SRT are registered trademarks of FCA US LLC.