I have a 2001 Honda Civic Ex 2dr coupe D17A2 with 1500 on it since rebuild
Had oversized pistons installed by .020
I just recently had a fully rebuilt engine put into my car and while the temps were above 30-40 degrees it would start fine. But under that it will crank but wont start. I took to mechanic and was told that it was fuel pump, so i replaced it. But still having this issue, I need ideas of things to check.
Battery, ALternator and ground cables are all good
-A

 

i had the exact issue and replacing the crank position sensor fixed it. not saying this is your problem, but something to look at, but its an expensive "test" because its a lot of labor to pay for unless you can do it yourself

 

What CEL codes are stored in the ECU?

 

The code is a P0420 Catalyst System Efficiency bank 1
i got it started today in 14f weather but i had to keep cranking it and pressing the gas pedal so i dont flood the engine

 

Could it be a wiring issue for the crank position sensor
A while back i had a code for crank position sensor intermittent but after the car starts it starts right up the next time as long as the engine doesn’t super cool

 

I would recommend testing the engine coolant temperature sensor.

 

Ive watched it closely usually whatever the outside temp There is usually a variation of 4-8 degrees Up from outside temp and its the same for the intake air temp

 

What are the cylinder compression numbers?

 

When i took it to the shop they did compression test and said that all 4 were 160 and above and had great compression

also thank you for responding i really appreciate it

 

In very cold weather when you have the cold start issue, does the engine start up quickly after you have warmed up the engine?

 

After the engine has finally started and has heated up it starts great every time as long as i don't let it sit for more then 5 hours and let it cool completely
which is what bothers me. The first start is always the roughest and its a rebuilt engine with a little less then 3k miles on it.

 

You may want to compression test the cylinders at low temps when the engine is difficult to start. The numbers may be informative.

You might also check whether adding a tablespoon of motor oil to each cylinder allows the engine to start at low temps.

 

I'll have to give that a shot Thank you

 

also it has oversisized cylinders .020 would that change anything?

 

Depends on how well the piston rings were fit.

 

Today it was 7F outside and it made no attempt to start it just kept cranking but literally had nothing besides listening to the starter spin the motor. even tried to jump it.

 

Have you tested the crank position sensor like previously mentioned?

I had to replace this after my water pump was changed. Coolant spilled on the sensor I think.

It wouldn't start because that sensor controls the timing of the motor I think.

Do you hear the fuel pump running when you try to start it? Spark plugs look good?