Code 0300 Random Missfire Problem

Code 0300 Random Missfire Problem

Postby Fierofly [OP] » August 12th 2014, 8:43pm

New Member Here, 2002 Astro with 130k RWD
Glad to find people still maintaining these vans, never understood why they quit making them. Anyway I've been chasing a random misfire for about six months now, and believe me this ONE could stump YOU.
1. It only sets a code after speeds above say 60mph or 45/50 with A/C on. You can fell the miss and if you decelerate the miss stays till around 35/40 mph, then you accelerate up and it comes back.
2. It idles excellent and runs great at speeds less then 45mph on the way back and forth to work and has no other codes.

parts changed so far.
1. Fuel pump, van would not start at work, thought for sure that was problem. NOT
2. Distributer, Found worn bearings while replacing plugs, wires rotor, cap and doing compression check (ck, Good), thought for sure that was the problem, NOT.
3. Did a fuel pump leak down ck, pressure held great.

So here's my thoughts and I'm hoping somebody has had something similar. Could this be a transmission induced problem maybe like a torque convertor lock up or something?

Thanks much and check out my hobby project
http://ls1tech.com/forums/conversions-h ... ion-7.html

Michael Thompson
Original Poster [OP]
Fierofly
Fueling (Empty tank)
Fueling (Empty tank)
Years of Membership: Fierofly has been a member for 6 full yearsFierofly has been a member for 6 full yearsFierofly has been a member for 6 full yearsFierofly has been a member for 6 full yearsFierofly has been a member for 6 full yearsFierofly has been a member for 6 full years
Posts: 6
Topics: 2
Joined: August 2014
Gender: Male
Alias (AKA):
Van Model Year: 2002
Van Make/Model: Chevrolet Astro

  • Similar topics
    Replies
    Views
    Author

Re: Code 0300 Random Missfire Problem

Postby BigWheelinBubba » August 12th 2014, 9:45pm

I would guess that condensation from the a/c is getting on the plug wire(s).
BigWheelinBubba
V8 Swap Achievement
V8 Swap Achievement
Fueling (7/8 tank)
Fueling (7/8 tank)
Years of Membership: BigWheelinBubba has been a member for 6 full yearsBigWheelinBubba has been a member for 6 full yearsBigWheelinBubba has been a member for 6 full yearsBigWheelinBubba has been a member for 6 full yearsBigWheelinBubba has been a member for 6 full yearsBigWheelinBubba has been a member for 6 full years
Posts: 87
Topics: 6
Images: 0
Joined: March 2014
Location: Warren, MI (Metro Detroit)
Gender: Male
Alias (AKA): Mike
Van Model Year: 1991
Van Make/Model: GMC Safari
Extra Info: LT1 4L60E RWD

Re: Code 0300 Random Missfire Problem

Postby Fierofly [OP] » August 12th 2014, 10:32pm

does it without AC on just at a higher MPH. Does it right away, you can feel the vibs before the code sets. I also checked the driveshaft and rear end.
Original Poster [OP]
Fierofly
Fueling (Empty tank)
Fueling (Empty tank)
Years of Membership: Fierofly has been a member for 6 full yearsFierofly has been a member for 6 full yearsFierofly has been a member for 6 full yearsFierofly has been a member for 6 full yearsFierofly has been a member for 6 full yearsFierofly has been a member for 6 full years
Posts: 6
Topics: 2
Joined: August 2014
Gender: Male
Alias (AKA):
Van Model Year: 2002
Van Make/Model: Chevrolet Astro

Re: Code 0300 Random Missfire Problem

Postby SPARKPLUG » August 12th 2014, 10:55pm

P0300 multiple random misfire I had this exact problem 2yrs ago turned out the dist cap
Was carbon tracked and cracked and diet drive gear was worei replaced the hole unit and problem
SPARKPLUG
250k+ Miles
250k+ Miles
Fueling (3/8 tank)
Fueling (3/8 tank)
Years of Membership: SPARKPLUG has been a member for 6 full yearsSPARKPLUG has been a member for 6 full yearsSPARKPLUG has been a member for 6 full yearsSPARKPLUG has been a member for 6 full yearsSPARKPLUG has been a member for 6 full yearsSPARKPLUG has been a member for 6 full years
Posts: 37
Topics: 8
Images: 8
Joined: June 2014
Location: summerton, sc
Gender: Male
Alias (AKA): matt
Van Model Year: 2000
Van Make/Model: GMC Safari
Extra Info: 4.3 rwd cargo


 
  • Related topics
    Replies
    Views
    Last post

Return to Engines

It is currently September 21st 2020, 3:31am

Engines Forum
Engine Repairs, Modifications, Diagnostics, Tuning, Upgrading, Questions.

<a href="https://ad.doubleclick.net/ddm/trackclk/N8334.275400VERTICALSCOPEINC./B20209277.204028354;dc_trk_aid=407011718;dc_trk_cid=94070067;dc_lat=;dc_rdid=;tag_for_child_directed_treatment="target="_blank"><img src="https://tpc.googlesyndication.com/pagead/imgad?id=CICAgKDrrqWwMRCAARgcKAEyCN4sAjjtai4k" border="0" align="right">
<IMG SRC="https://ad.doubleclick.net/ddm/trackimp/N8334.275400VERTICALSCOPEINC./B20209277.204028354;dc_trk_aid=407011718;dc_trk_cid=94070067;ord=;dc_lat=;dc_rdid=;tag_for_child_directed_treatment=?" BORDER="0" HEIGHT="1" WIDTH="1" ALT="Advertisement">
Moderator: chevy57bert
To create a new topic in Engines, click this button:
Previous topic Next topic
Recent Image Attachments
Attached by:
Maddog
in Engines
Views: 403
Comments: 31
Date: Sep 18 '20
Time: 11:15pm
» Read last comment
Attached by:
Maddog
in Engines
Views: 403
Comments: 31
Date: Sep 18 '20
Time: 10:47pm
» Read last comment
Attached by:
Maddog
in Engines
Views: 403
Comments: 31
Date: Sep 18 '20
Time: 10:43pm
» Read last comment
Attached by:
Maddog
in Engines
Views: 403
Comments: 31
Date: Sep 18 '20
Time: 10:40pm
» Read last comment
Attached by:
erikw9
in Engines
Views: 821
Comments: 37
Date: Sep 14 '20
Time: 7:30pm
» Read last comment
Sponsors

Who is online

Users browsing this forum: No registered users and 21 guests