[Sliding]

Hello everyone I have a 2003 Chevy s10 4.3 & recently I been having a problem where when the truck sits for 4 hours or so the truck doesn’t start unless I press the gas straight to the floor (fuel injected vehicle). After that it runs at high rpm and almost sounds like I have a cam (which I dont)
Then after it runs for alittle the rpm goes down to normal & after that I can turn it off and on without having to press the gas. Since I have changed many parts everything to do with spark (sparkplugs,spwires,distributor cap,coil pack,rotor,) also ect sensor , MAF sensor, thermostat,fuel filter and new spider fuel injectors with fuel pressure regulator). I am befuddled at this point and font know what to do next. Any advice or anyone had this problem as well? Or should I just sell the damn truck .
Please and thank you 🙏

 

[Rhotpursuit]

What about the TPS and IAC?

 

[Rebel n Dirt]

Are the injectors pulsing or are they stuck on. It sounds like the truck is getting flooded. I would look at fuel pressure and also fuel pulse. Noid lights for checking pulse.

 

[nickandre]

If it's temp dependent, it can indicate a problem with the temp sensors (either engine coolant temp or intake air temp). If the ECT is out of whack you can get times where the engine will flood or run excessively lean due to the computer assuming it needs different amounts of fuel based upon the incorrect temp. You should be able to view it with a basic scan tool, check to make sure they make sense when cold/up to temp.

 

[oldeerslayer]

That's what I would look into. Have had a couple ECT's go bad. Actually one was a broken wire at the sensor.

 

[bk2life]

Full throttle commands no fuel to injectors at start up. ‘Rebel n Dirt’ I believe has it right, about being flooded.

Are there any codes stored?

And, verify fuel pressure and leak down pressure.

 

[Sliding]

What about the TPS and IAC?

I have changed the IAC but never the TPS should I still change it even though theres no codes ?

 

[Sliding]

What about the TPS and IAC?

Are the injectors pulsing or are they stuck on. It sounds like the truck is getting flooded. I would look at fuel pressure and also fuel pulse. Noid lights for checking pulse.

They’re new fuel injectors from summit racing with a new fuel pressure regulator as well. Haven’t checked for pulsing yet !

 

[Sliding]

If it's temp dependent, it can indicate a problem with the temp sensors (either engine coolant temp or intake air temp). If the ECT is out of whack you can get times where the engine will flood or run excessively lean due to the computer assuming it needs different amounts of fuel based upon the incorrect temp. You should be able to view it with a basic scan tool, check to make sure they make sense when cold/up to temp.

Right on but I also have no check engine light and no codes. I have changed all temp related parts but still nothing. Maybe I have a bad wiring on my ect .

 

[Sliding]

That's what I would look into. Have had a couple ECT's go bad. Actually one was a broken wire at the sensor.

How’d you fine the problem with the wire ? And also were any codes coming up ?

 

[Sliding]

Full throttle commands no fuel to injectors at start up. ‘Rebel n Dirt’ I believe has it right, about being flooded.

Are there any codes stored?

And, verify fuel pressure and leak down pressure.

You believe so ? They’re new injectors maybe they can faulty from factory & whenever I run the truck with having to start it with the gas to the floor after I run it the temo gauge stays at 100 & then I get a p0125 but I changed everything temp related. (Thermostat,ETC,New coolant) & will do need to get to the tool will write back after thanks.

 

[Sliding]

Thank you all for being so nice as well. I really appreciate it and happy new years !

 

[nickandre]

These things don't always set codes. There's no fuel pressure sensor on port injected vehicles, nor will a temp sensor that's displaying a plausible but faulty reading trip a code. Sometimes a broken wire will trip a circuit code, but the computer itself has to actively check for that.

Broken wire diagnoses are a bit annoying. You need to first establish that the wire is high resistance -- sometimes the wire can be corroded and have a very high resistance. You can still sometimes get full voltage (i.e. you might see 12V on a supply wire with a volt meter) but if you apply a load like a turn signal bulb you'll see it can't carry current. You do want to be careful sending arbitrary voltage into the computer though, don't just apply 12V to a 5V sensor circuit.

Once you establish the wire is ded you'll have to figure out where it goes, find any connectors it runs through and split the wire run in half. Then you get to enjoy hunting for chafage or rodent activity. Eric O usually does a great job showing the process: