Hard cold start 2.7l Tacoma Please help
01-24-2017, 11:50 AM
#1
Registered User
Thread Starter
Hard cold start 2.7l Tacoma Please help
Hey guys I just replaced my head, fuel filter, timing chain and vibration dampener chain because of some severely burnt valves. Everything went great and when the truck does start it runs great. That leads me to believe that it's not my fuel, or spark. Anyone know what sencers it could be?
01-25-2017, 11:36 AM
#2
Primary sensor is the engine coolant, secondary is intake air temperature.
First step is always to inspect battery voltage, and look for loose connections at the battery terminals. Then loose connections to sensors.
Battery voltage sag during cranking, this effects all sensors aswell as the injector pulse.
You've had the battery disconnected, was it placed onto a charger?
You've also had the wiring harnesses disconnected, are the terminals well seated? Were the contacts cleaned?
Does pushing the accelerator to the floor make it come alive? This allows the engine to reach a higher cranking rpm, aswell the 3rz uses a "kick down switch" located under the pedal for triggering fuel enrichment but I'm not sure that circuit is active during cranking.
First step is always to inspect battery voltage, and look for loose connections at the battery terminals. Then loose connections to sensors.
Battery voltage sag during cranking, this effects all sensors aswell as the injector pulse.
You've had the battery disconnected, was it placed onto a charger?
You've also had the wiring harnesses disconnected, are the terminals well seated? Were the contacts cleaned?
Does pushing the accelerator to the floor make it come alive? This allows the engine to reach a higher cranking rpm, aswell the 3rz uses a "kick down switch" located under the pedal for triggering fuel enrichment but I'm not sure that circuit is active during cranking.
01-25-2017, 03:20 PM
#3
Registered User
Thread Starter
Thanks for the reply!
So I've checked all the connections, they are good, battery is new as of 2 months ago so it should be fine (although I'm going to check it because of all the excessive cranking it's been doing).
That's good to know about the air temp sensor I'll have to check that with my volt meter.
gas pedal does nothing when cranking; in fact when the truck starts running and I push the pedal it tries to stall out. So what I have to do is depress it slowly to get the RPMs up.
So I've checked all the connections, they are good, battery is new as of 2 months ago so it should be fine (although I'm going to check it because of all the excessive cranking it's been doing).
That's good to know about the air temp sensor I'll have to check that with my volt meter.
gas pedal does nothing when cranking; in fact when the truck starts running and I push the pedal it tries to stall out. So what I have to do is depress it slowly to get the RPMs up.
01-25-2017, 04:35 PM
#5
Registered User
Thread Starter
Hard cold start.
I have to crank my engine >25 times letting it rest for intervals before it starts. and when it does start it idles low for a few minutes then runs fine.
It has new spark plugs, wires and everything else listed above.
I have to crank my engine >25 times letting it rest for intervals before it starts. and when it does start it idles low for a few minutes then runs fine.
It has new spark plugs, wires and everything else listed above.
01-25-2017, 04:57 PM
#6
Registered User
Thread Starter
Hard cold start.<br /><br />I have to crank my engine >25 times letting it rest for intervals before it starts. and when it does start it idles low for a few minutes then runs fine.<br /><br />It has new spark plugs, wires and everything else listed above.
Last edited by clayton707; 01-25-2017 at 05:03 PM.
