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blue62 · 09-07-2019, 08:29 PM

If I am following you correctly you are having a cold start problem.

Most "cold" hard to start issues are due to not having a rich enough fuel air mixture.

Think of carburated engines back in the 50,s and 60's you had to pull a hand choke to give it a richer fuel mixture when starting cold.

So with that in mind I would say you have unmetered air entering the intake. (vacuum leak). or a possible faulty coolant temp. sensor, gauge, or a problem with the wiring related to the coolant temp sensor or gauge.

The ECU reads the coolant temp. as one of the things to determine how long to pulse the fuel injectors on startup.

I would buy a vacuum gauge (15-20 dollars) and do a "PROPER" vacuum test.
Should read 21 inches of vacuum at idle with a steady needle.
Then make sure your coolant temp sensor, gauge and all related wiring are in order.

That would be my starting point.

09-07-2019, 08:29 PM	#2
blue62 Registered User Join Date: Aug 2018 Location: Woodland Wa Posts: 1,309	If I am following you correctly you are having a cold start problem. Most "cold" hard to start issues are due to not having a rich enough fuel air mixture. Think of carburated engines back in the 50,s and 60's you had to pull a hand choke to give it a richer fuel mixture when starting cold. So with that in mind I would say you have unmetered air entering the intake. (vacuum leak). or a possible faulty coolant temp. sensor, gauge, or a problem with the wiring related to the coolant temp sensor or gauge. The ECU reads the coolant temp. as one of the things to determine how long to pulse the fuel injectors on startup. I would buy a vacuum gauge (15-20 dollars) and do a "PROPER" vacuum test. Should read 21 inches of vacuum at idle with a steady needle. Then make sure your coolant temp sensor, gauge and all related wiring are in order. That would be my starting point. Last edited by blue62; 09-07-2019 at 08:38 PM.