99 Suburban.. No Start When Cold

RaysZ71 · February 10, 2008

Its getting fuel, i think too much, its acting like it is flooding, I check the number 1 plug and its wet. I am getting spark, and if I let it sit and hold the gas to the floor it will try to start.

I am wondering If I have a sensor failing, like the iat?

RaysZ71 · February 11, 2008

anybody...

bobcat5544 · February 11, 2008

Are you getting spark on all cylinders

RaysZ71 · February 11, 2008

Are you getting spark on all cylinders

Yes.. If i get the cylinders to clear out, It will start. I have to hold the peddle to the floor and let it crank for a long time, and I have gotten it to start once. it ran fine after it started and cleared it self out.

Its seems to be getting too much fuel at startup.

bobcat5544 · February 11, 2008

pull of the air cleaner and look at the two fuel injectors have some one turn the key on and then turn it off. do the fuel injectors leak fuel when the key is off.

RaysZ71 · February 11, 2008

pull of the air cleaner and look at the two fuel injectors have some one turn the key on and then turn it off. do the fuel injectors leak fuel when the key is off.

Its not a TBI. Its the SCPI. I can not see the injectors.

I have done some searches, and it looks like the ECT sensor may have something to do with it. Where is that located?

bobcat5544 · February 11, 2008

I forget sometimes that gm changed over from tbi to scpi.

The ECT sensor is loctated next to the Thermostat houseing.

RaysZ71 · February 11, 2008

I forget sometimes that gm changed over from tbi to scpi.

The ECT sensor is loctated next to the Thermostat houseing.

Am I looking in the right direction? Engine getting too much fuel to start, flooding it. What happens if I disconnect the sensor, does the computer use a defualt value, I wonder if I can test it this way?

bobcat5544 · February 11, 2008

when it is unpluged the computer does use a defualt value. You can try it. The ect sensor does control fuel amount.

HawkScot · February 11, 2008

Not sure if it is your problem, but my daughter went start the 98 Yukon 2 weeks ago after some really cold weather and it fired a few times (like it was out of time), then cranked strange, then just cranked... I had changed the intake gaskets in December so was figuring I screwed something up (like not tightening down the distributor holddown or something). I had purchased a new rotor and cap that I was planning on installing when the weather warmed up (didn't want to change them when I replaced the intake gaskets as the old ones had my marks on them to get the distributor back in correctly). I changed the cap and rotor and it fired right up, no problems. I am guessing that maybe I had a crack or something and the moisture/condensation from the cold weather/warm engine caused a problem. In any case, that was a couple of weeks ago and it is still running fine.