Could PCM cause injector to stay open?

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

Could PCM cause injector to stay open?

Printable Version

Blazer Forums >> Mechanical & Maintenance >> Engine & Transmission >> Could PCM cause injector to stay open?

Page: [1]

Message

<< Older Topic Newer Topic >>

Could PCM cause injector to stay open? - 3/27/2008 2:06:52 PM

bkr0825

Posts: 2
Joined: 3/27/2008
Status: offline

Hello,

I have a '97 Chevy Blazer, 4.3L 'w' 148K miles.

I am getting code p0302, misfire in cylinder #2. I have read a lot of forums that talk about all the possiblities / causes of misfire in a cylinder that have been really helpful. I have recv'd no other codes. My service engine soon light comes on and flashes then will go back to steady on. No power, hesitates horribly, idles horribly and the oil pressure guage drops to 20. This has been going on for past four months or so and thought its not worth driving anymore because I dont want to cause further damage. (Which I probably have already!)

I have completed the following repairs with in last two months;
---New upper intake manifold gasket, new AC delco distributor, cap, rotor, plugs (AC delco platinum), AC wires, ignition switch, new style complete spider injection system (MFI), new MAP sensor, upper engine vacuum hoses, new EGR valve, all new four O2 sensors, and air cleaner. I bought a new high flow Cat but have not changed it out yet. I hate to use the word assume but since there is only one coil I figured it must be ok or I wouldn't get spark on any of the wires / or it wouldnt start.

I tested the #2 spark plug wire and have a good spark. I pulled the #2 spark plug out and observed it soaked in gas. I tired to blow out the gas but it appears the #2 cylinder is full of gasoline and the oil level is up approximately 1/4 inch on the oil dip stick so it appears the gasoline that is not burning up is going right into the crankcase. I recv'd the #2 misfire before the new spider injection was replaced and still getting it now.

I have not replaced the ignition module, knock sensor or TPS. Could those be the cause? I was thinking maybe the PCM is defective and telling the #2 injector to stay open thus continually pumping raw gas directly into the cyclinder at such a rate there is no combustion what so ever. Could the large plug that plugs on top into the spider injection fuel meter be defective? I tried to look into the cylinder with a scope and all I could really see was the top of the piston which appeared to be clean. Please help!!! I think its time I give up and just take it to the professionals. When I had the upper intake gasket replaced there was no head gasket leak, it had good compression.

Thanks for any help.
Bryan

Post #: 1

RE: Could PCM cause injector to stay open? - 3/27/2008 2:17:54 PM

swartlkk

Posts: 15304
Joined: 5/1/2005
From: Waterloo, NY
Status: offline

If only one cylinder is doing it, sounds like you have a bad injector on your new spider. I would pull the plenum off and reinstall the fuel lines, then pull the #2 injector out of the lower intake and pressurize the system. If it leaks without any electrical wires attached, then the injector is bad.

_____________________________

Kyle-

My Restoration Projects
Please Do Not PM for Tech Help

(in reply to bkr0825)

Post #: 2

RE: Could PCM cause injector to stay open? - 3/27/2008 7:00:51 PM

bkr0825

Posts: 2
Joined: 3/27/2008
Status: offline

Thank you for your quick response. Unfortunately I will not be able to get at it until Saturday or Sunday but I will definately give that a try!! I'll let you know how it goes.

Bryan

(in reply to swartlkk)

Post #: 3