2000 sonoma skipping - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 10-12-2008, 08:27 AM
woodmanscott@hotmail's Avatar
Registered User
 
Last photo:
Join Date: Dec 2005
Location: thomaston ga
Age: 41
Posts: 115
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
2000 sonoma skipping

my 2000 sonoma keeps skipping even after new plugs wires cap crank sensor..i even changed the engine (not due to the skip) put in a junk yard engine used all the parts from the jy engine and it is still showing multiple mis fire p300 code good comp and no iol burn on jy engine new wires and cap button etc and i am still getting p300 i am at a loss as to what is going on


the oringinal engine bent a push rod and broke two rocker arms so boss bought a jy engine cause we had to order all the parts from different store and needed it right away

any ideas what is making this engine skipp and jerk the chance of getting an engine with same problems that the old one has is rare i would think please help i am running out of hair to pull out

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 10-12-2008, 11:34 AM
powered by 1.21 gigawatts
 
Last photo:
Join Date: Jan 2008
Location: bucks county pa
Posts: 71
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
firing order out of whack?
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-12-2008, 12:13 PM
woodmanscott@hotmail's Avatar
Registered User
 
Last photo:
Join Date: Dec 2005
Location: thomaston ga
Age: 41
Posts: 115
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
no firing order out of whack....engine was running whne i removed it from the truck in the junk yard...
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-12-2008, 02:13 PM
Member
 
Last photo:
Join Date: Feb 2003
Posts: 642
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Do a fuel quality/quanity test as well as check fuel pressure.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 10-12-2008, 03:40 PM
Member
 
Last wiki edit: Ford axle ratio codes
Last journal entry: Rear Suspension
Last photo:
Join Date: Aug 2005
Location: Prattsville
Posts: 6,359
Wiki Edits: 31

Thanks: 2
Thanked 54 Times in 50 Posts
P0300 is a misfire code for all cylinders.. I think you might find a coil is faulty.. fuel preassure first tho
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 10-12-2008, 05:09 PM
woodmanscott@hotmail's Avatar
Registered User
 
Last photo:
Join Date: Dec 2005
Location: thomaston ga
Age: 41
Posts: 115
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
new coil but thta dont mean alot....will check it out and see if the old coil that is on the engine that i pulled out is any good...but i was getting p303 p304 when the old engine was in have no clue and the fuel presure is 52 lbs
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 10-12-2008, 05:39 PM
Registered User
 
Last photo:
Join Date: Nov 2006
Location: Woodstock
Posts: 869
Wiki Edits: 0

Thanks: 2
Thanked 68 Times in 62 Posts
Fuel pressure should be 56-66 psi with Key On Engine Off. With teh engine running it will be slightly lower as the vacuum referenced fuel pressure regulator brings it down with high engine vacuum. WHen teh engine is revved the pressure should spike.

1) Did you use your original distributer when you swapped engines?
I have seen missing caused by even wear on the distributer gear.

2) Was the original intake manifold and injection used on the new engine.

3) When does it skip? At idle or at light loads going down the road?

4) If you unplug the EGR motor at the front of the engine on top of the intake manifold (round black canister looking thing with a 5 prong weather pack connector) does the skipping cease?

peace
Hog
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 10-12-2008, 06:32 PM
Member
 
Last wiki edit: Ford axle ratio codes
Last journal entry: Rear Suspension
Last photo:
Join Date: Aug 2005
Location: Prattsville
Posts: 6,359
Wiki Edits: 31

Thanks: 2
Thanked 54 Times in 50 Posts
Quote:
Originally Posted by woodmanscott@hotmail
new coil but thta dont mean alot....will check it out and see if the old coil that is on the engine that i pulled out is any good...but i was getting p303 p304 when the old engine was in have no clue and the fuel presure is 52 lbs
that's missfires on cyls 3 and 4, but I doubt the coil has anything to do with it now.. it's the same symptoms but diffrent between the 2 engines... fuel preassure, or a sensor that you didn't replace is off.. if you check fuel preassure, check it with the fuel preassure regulator vac hose disconnected, then connect it. should drop 5 PSI at idle
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 10-12-2008, 06:48 PM
Registered User
 
Last photo:
Join Date: Nov 2006
Location: Woodstock
Posts: 869
Wiki Edits: 0

Thanks: 2
Thanked 68 Times in 62 Posts
the fuel pressure regulator is inside of the intake manifold, therefore exposed to manifold vacuum directly, you cant attach and detach the FPR line.

The same thing can be accomplished by checkingthe fuel pressure at Key on Engine off and then with the engine running. These pressures should be at least 5 psi different.

peace
Hog
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 10-12-2008, 07:26 PM
woodmanscott@hotmail's Avatar
Registered User
 
Last photo:
Join Date: Dec 2005
Location: thomaston ga
Age: 41
Posts: 115
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Hogg
Fuel pressure should be 56-66 psi with Key On Engine Off. With teh engine running it will be slightly lower as the vacuum referenced fuel pressure regulator brings it down with high engine vacuum. WHen teh engine is revved the pressure should spike.

1) Did you use your original distributer when you swapped engines?
I have seen missing caused by even wear on the distributer gear.

2) Was the original intake manifold and injection used on the new engine.

3) When does it skip? At idle or at light loads going down the road?

4) If you unplug the EGR motor at the front of the engine on top of the intake manifold (round black canister looking thing with a 5 prong weather pack connector) does the skipping cease?

peace..................Hog
i used the distributer that came in the engine..i have not tried to unplug the egr motor it skips real bad at start up and surges going down th eroad..then it skips off and on all day under a load or not but i will check th egear tomorrow when the wife gets home with it ....but it also will start up and skip just s few times and run just fine for a day or 2 then back to acting up i am running 8mm wires and platnum plugs
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 10-12-2008, 07:30 PM
woodmanscott@hotmail's Avatar
Registered User
 
Last photo:
Join Date: Dec 2005
Location: thomaston ga
Age: 41
Posts: 115
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Hogg
the fuel pressure regulator is inside of the intake manifold, therefore exposed to manifold vacuum directly, you cant attach and detach the FPR line.

The same thing can be accomplished by checkingthe fuel pressure at Key on Engine off and then with the engine running. These pressures should be at least 5 psi different.

peace
Hog
this is the second pump in the tank i have replaced it twice and the fuel pressure is that same around 50-52lbs but what i dont under stand is the plugs are showing perfect burn (as shown in any book) i have played with the gap slightly more than factory and slightly less i have even indexed the plugs still the same thing on the orignal engine it started this skipping under heavy acceleration when it skip it would flutter like a valve was sticking then it would go away for weeks now it is everyday
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 10-13-2008, 06:54 AM
Member
 
Last photo:
Join Date: Feb 2003
Posts: 642
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
What size engine???? Fuel pressure requirements are different for different engines. You also never mentioned if you did a fuel quality/quanity test..
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 10-13-2008, 09:52 AM
woodmanscott@hotmail's Avatar
Registered User
 
Last photo:
Join Date: Dec 2005
Location: thomaston ga
Age: 41
Posts: 115
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
[QUOTE=HalfOunce]What size engine???? Fuel pressure requirements are different for different engines. You also never mentioned if you did a fuel quality/quanity test..[/QUOT

4.3 v-6 2000 yr

fuel pressure is between 52 and 56 lbs

the quality is great (it smelled fresh to me) dont know how to test the quality of the gas other than it not having a stagnet odor to it

as far as the quanity i hooked up a hose to the pressure test port and it sprayed a stream ruffly 8" from the end of the hose 3/8 in diamater

also i have had the tank out in the last year when i put the new pump in and it was nice an shinny


also this morning when i went to crank it all it would do is spin over and a soon as you let the key up it would fire off but dies just as quick..it took me several hours of holding it to the floor spinning it a couple of times and the wait a spell (hour) then crank it with out touching the pedal

whne it did fire up it soundded like it was trying to clear its throat and bellowed out a large cloud of white smoke(unburnt fuel) ??? then it idle just fine and then when you step on the gas it would stumble nd take off skipping every so often..i am sorry to ramble about but that is what it ias doing
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 10-13-2008, 11:42 AM
Member
 
Last photo:
Join Date: Feb 2003
Posts: 642
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
fuel pressure for a 2000 4.3 is supposed to be 60-66 psi
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 10-13-2008, 07:55 PM
Registered User
 
Last wiki edit: Hand cleaner Last photo:
Join Date: Jun 2008
Location: Houston
Posts: 170
Wiki Edits: 3

Thanks: 0
Thanked 2 Times in 2 Posts
Quote:
when it did fire up it soundded like it was trying to clear its throat and bellowed out a large cloud of white smoke(unburnt fuel) ???
that sounds like your fuel pressure regulator is leaking into the intake. its a pretty common problem.

did you use a good quality cap? IIRC, cylinders 3 & 4 are the ones that run besides each other and cross over in the cap. i've seen cheap caps burn thru in that area & cause an
intermittent misfire.

also, some of the injectors may be sticking. i don't remember if your motor came with the poppet type injectors or not. they are known for causing problems.
the poppet injectors are opened by the fuel pressure & they must have at least 55 PSI to open. you normally see about 62 PSI at idle with the CPI system.
i have replaced a good number of the CPI spiders because of bad injectors.

if it does have the CPI poppet system & you find problems with it, GM has a retro kit to change the CPI system over to MPI. it comes as a complete assembly.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
What is a 'hotrodder'? BillyJoe Hotrodding Basics 138 05-25-2013 05:06 PM
Pro Topline Heads surfinca Engine 33 12-28-2008 11:37 AM
2000 GMC Sonoma brake problems woodmanscott@hotmail Suspension - Brakes - Steering 15 10-13-2008 04:17 PM
tranny removal 2000 gmc sonoma woodmanscott@hotmail Transmission - Rearend 2 07-08-2008 01:32 PM
1991 Sonoma ABS Question bluesman123 Suspension - Brakes - Steering 5 05-13-2003 07:34 PM


All times are GMT -6. The time now is 05:39 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.