|
|
|
engine light on truck missing real bad
|
|
|
| |
|
|
Guest
Anonymous Poster
talford174@charter.net
Oct 13, 2006, 3:26 AM
Post #1 of 6
(2985 views)
|
|
engine light on truck missing real bad
|
Sign In
|
|
99 s10 4.3, engin has been missing as soon as starting to drive and then would run fine after 10 miles. replaced plugs, wires, and coil. engine light came on this morning and missed even worse. code p0300 says multible cylender missfire, any one know what my problem is. thanks
|
|
| |
|
|
DanD
Veteran
/ Moderator
Oct 13, 2006, 4:19 AM
Post #2 of 6
(2982 views)
|
|
Re: engine light on truck missing real bad
|
Sign In
|
|
Considering you’ve already replaced a bunch of ignition parts and still have the misfire. I would scan the computer’s data stream watching the misfire counter; to see if I could pick out which cylinder(s) were actually misfiring.
If that doesn’t narrow things down: as in all cylinders were misfiring equally, I would start looking for common to all cylinder items. Low fuel pressure, vacuum leaks ect.
This truck has central injection; in other words there is one central injector and six poppet nozzles one for each cylinder all connected by tubing. The injector is opened electrically via the computer; the poppet nozzles are opened mechanically by fuel pressure. Something like an older diesel engine injector.
If these poppet nozzles are dirty they maybe sticking closed and not feeding fuel to all cylinders equally or not at all.
What I’m getting to; is maybe have the injection system professionally cleaned; don’t waste your money on the pour in the tank crap. Most garages will have some form of cleaning system/machine that will do a much better job.
If you do find that the problem is in the injection system and cleaning hasn’t helped; GM has a retrofit to replace the central injection and change it up to multi port. Works real neat you remove the upper intake, the old injector and poppet nozzles and install this new system that will have an injector for each cylinder. No other changes are needed all the old wiring attaches to it.
GM wouldn’t have spent the money to redesign this if they didn’t know they had a problem with the old system.
Dan.
Canadian "EH"
|
|
| |
|
|
Guest
Anonymous Poster
Oct 13, 2006, 3:05 PM
Post #3 of 6
(2978 views)
|
|
Re: engine light on truck missing real bad
|
Sign In
|
|
thanks for the info, someone also told me it could be the fuel pump going bad
|
|
| |
|
|
DanD
Veteran
/ Moderator
Oct 13, 2006, 3:11 PM
Post #4 of 6
(2976 views)
|
|
Re: engine light on truck missing real bad
|
Sign In
|
|
Could be’s can be expensive; have the fuel pump pressure tested for available pressure and leak down; preferably while the truck is going its thing.
Dan.
Canadian "EH"
|
|
| |
|
|
Guest
Anonymous Poster
Oct 13, 2006, 3:45 PM
Post #5 of 6
(2973 views)
|
|
Re: engine light on truck missing real bad
|
Sign In
|
|
how do you pressure test a pump. thanks trying to avoid overpaying a garage if i can do it
|
|
| |
|
|
DanD
Veteran
/ Moderator
Oct 13, 2006, 5:33 PM
Post #6 of 6
(2969 views)
|
|
Re: engine light on truck missing real bad
|
Sign In
|
|
Well you would need a fuel pressure gauge connected to the service port; know what the proper pressure rating is and the time frame that is allowable for leak down.
So at times a garage maybe your only choice other then buying the equipment yourself and learning the proper test procedures.
I know at times going to a new repair facility can be unsettling as to their reliability. But if you walk in showing trust, a working knowledge of your vehicle; they will respect you and that knowledge.
Hopefully you have learned a little here and show whoever that you’ve done your research. Keeping an opened mind and willing to listen to their recommendations you’ll get this repaired. If at anytime you’re unsure of their diagnosis post back here. We’ll try and help.
Dan.
After rereading what I’ve posted I thought that I should add this in regards to repair facilities. We are not the most respected profession because so many people “know their vehicles” but I’ve have been in this trade for almost thirty years now and I learn new things every day. The more people in general learn about their vehicles as what you are trying to do will make my job so much easier.
Thanks for posting your help question!!!
Canadian "EH"
(This post was edited by DanD on Oct 13, 2006, 5:50 PM)
|
|
| |
|
| | |
|
Auto Repair Home
SEARCH
WHO'S 
LOG 
multiple warning lights
Please Help - Knock sound & engine fail
Brake Seals Bulging
