If you're getting black smoke at start-up, I suspect you've got leaking injectors. A fuel pressure tester will help you with that. The pressure should hold for quite awhile after the engine is turned off.
The other thing it could be is a temperature sensor that's telling the ECM that it's minus 300°. I'm exaggerating a little, unless you're in Edmonton, but you get the picture.
[EDIT] Gall, you posted while I was searching for the perfect paper clip image.
[This message has been edited by Patrick (edited 04-16-2016).]
If you have no codes set, I would look to the Coolant Temperature Sensor, located on the passenger end of the engine, hidden underneath the bottom of the thermostat housing neck and behind the EGR solenoid. Sits horizontally, screwed into the lower intake. A search for temp sensor may give you a diagram of its location. This sensor supplies the ECM with info used to control injector fuel flow.
Edit: I'm not in Alberta but when the CTS failed in my 87, it was telling the ECM it was -28°f on a Georgia summer afternoon.
[This message has been edited by fierofool (edited 04-16-2016).]
I was working on an 85 GT that ran rich, and the problem was the engine temperature sensor was disconnected. That's something to check, even if it's connected.
,,,search for flooding in technical discussion title/username.
Charlie, isn't the following what you're referring to? If so, a link was already provided.
CLEAR FLOOD MODE If for some reason the engine should become flooded, provisions have been built into the computer to help clear this out. If during cranking of the engine you depress the throttle more than 80%, the ECM will enter what is called “clear flood mode”. In this mode the ECM commands a delivered Air/Fuel ratio to very lean (usually 20:1). The ECM will stay in clear flood mode as long as the throttle is 80% or higher and the RPMs are less than about 600. As soon as throttle position falls below the 80% threshold or RPMs go above 600, the ECM disables clear flood mode and calculates fuel delivery based on coolant temperature and other factors it normally uses.
the Pontiac dealer already changed everything they could related to the issue (outside of replacing the entire engine) and still to this day it isn't fixed.
Why don't you start a thread on your car and get better advice than 'change everything' from a dealer?
Sorry for the duplication but yes, Pat, that is the link. I was in the grocery store working from a small phone and missed all the replies while I was searching for something to back me up.
[This message has been edited by fierofool (edited 04-17-2016).]
It bugs the crap out of me......starts up with a little puff of black.
I hate that almost as much as cutting the grass. LOL
Leaky injectors will do that. Check to see if fuel pressure falls quickly after you turn the car off. Pressure should hold for about 5 minutes.....otherwise it is leaking into the cylinders.
, but it has to turn over longer to start.
