RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER

	Blazer Forum Classifieds Photo Gallery Search Contact BF Sponsors
Blazer News Member List Forum FAQ Timeslips Recalls TSBs Calendars Register Login

RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER

Printable Version

Blazer Forums >> Mechanical & Maintenance >> General Tech Help >> 2nd Gen (1995-2005) Tech >> RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER

Page: << < prev 1 2 3 [4]

Message

<< Older Topic Newer Topic >>

RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER - 1/11/2008 8:48:28 AM

boarder

Posts: 4
Joined: 1/10/2008
Status: offline

no problem. din't mean to hi-jack the thread.

(in reply to swartlkk)

Post #: 61

RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER - 1/11/2008 8:55:27 AM

quinnman105

Posts: 591
Joined: 8/16/2007
Status: offline

quote:

ORIGINAL: boarder

no problem. din't mean to hi-jack the thread.

Sorry Kyle

_____________________________

2001 Chevy Blazer
4x4, 4dr
4.3L Vortec V6

(in reply to boarder)

Post #: 62

RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER - 1/11/2008 9:09:55 AM

swartlkk

Posts: 14308
Joined: 5/1/2005
From: Waterloo, NY
Status: offline

No, not a problem at all. No hijack either, but trying to help both of you in one thread was getting a bit confusing.

_____________________________

Kyle-

2004 Rainier
1970 Chevelle - Resto
1974 K5 Blazer - Resto

(in reply to quinnman105)

Post #: 63

RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER - 1/11/2008 9:58:39 AM

myronhntr80

Posts: 54
Joined: 11/24/2006
From: Idaho
Status: offline

Have you thought that you may have a bad ecm? I work in an auto parts store and I have seen it more than once. Very rare but it does happen.

_____________________________

1993 Blazer 4.3 vortech cpi 4x4 Auto. trans. 4 door LT package. 2" shackles tb crank Mickey Thompson Baja MTZ 31 10.50 r 15

(in reply to swartlkk)

Post #: 64

RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER - 3/6/2008 8:36:51 AM

DOINSND

Posts: 1
Joined: 3/5/2008
Status: offline

Hello new to site

Did you figure out problem

Blazeofglory (gator)

I read the entire post. Im shaking my head my 96 blazer is doing the same thing. I started with change fuel pump & filter to cap rotor wires plugs seafoam twice. Tired of spending money on no fix. Took it to a shop the first time said it was coil and wires. I changed coil wires no fix I had a used coil off a sandrail build. Then the shop said it was fuel pressure regulator, they changed that still no fix. Took it back they said it was still the coil showed me on the side of coil white marks and stated high voltage. So I changed to a new coil wires plugs. still misses not as bad. My wife is driving it so you know my pain!!!!!!!

I going to take it to the dealer to see if they can figure it out.

Could it be the ECM??

_____________________________

JUST DUNE IT!!!!

(in reply to boarder)

Post #: 65

RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER - 3/7/2008 1:25:27 PM

polecat

Posts: 22
Joined: 3/7/2008
Status: offline

not sure if this is relevant or not or if it will help anyone as I have not confirmed it as of yet I just bought my 98 blazer it seems to have the same problem surges and sputters around 1500 to 2500 rpms under light acceleration but not under hard acceleration or at idle I have plans to fix it next weekend I have done a lot of research on this and one major one that I have not seen listed as of yet is a leaking intake manifold gasket. Like I said I have not confirmed this as of yet but more than one mechanic that I have talked to has told me this can cause the problem and is very often overlooked I will update once the repairs have been made to let you know if this fixes the problem.

_____________________________

98 blazer 4.3 V6 4x4
94 blazer 4.3 V6 4x2

(in reply to DOINSND)

Post #: 66

RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER - 3/7/2008 4:06:32 PM

swartlkk

Posts: 14308
Joined: 5/1/2005
From: Waterloo, NY
Status: offline

A leaking intake manifold gasket should be found through all of the vacuum leak diagnosis already suggested here. If the intake manifold were leaking, it would result in a misfire. I would think it would result in a cylinder specific misfire (P030x where x is the misfiring cylinder).

For those going through this thread, I have created a P0300 Explained thread in the DIY section.

_____________________________

Kyle-

2004 Rainier
1970 Chevelle - Resto
1974 K5 Blazer - Resto

(in reply to polecat)

Post #: 67

RE: The dreaded PO300 CAUTION LONG POST AND GETTIN LONGER - 3/8/2008 6:24:13 AM

polecat

Posts: 22
Joined: 3/7/2008
Status: offline

good point sorry I must have missed where he searched for the vacuum leak I'll make sure I read more thoroughly next time

_____________________________

98 blazer 4.3 V6 4x4
94 blazer 4.3 V6 4x2

(in reply to swartlkk)

Post #: 68