Well i went to start it tonight it was a little chilly out like 30 ish and it cranked right over but immediatly turned off as the rpms did not catch. I also noticed that my lights dim a considerable amount when the gas pedal is pressed for some strange reason since this engine swap. The only way i could get her to stay running in the cold is to hit the gas a couple times. In warmer weather it starts right up any ideas on what could be causing this issue ?

 

First off, which TB are you using, secondly if so are you using the IACV(DEK) and also did you bypass the coolant lines through the TB?

 

im using the 5th gen TB, with a 4th gen iacv adapter plate. I do not have any coolant lines going through the EGR system nor the Throttle body

 

I would start by redoing your harness grounds and going from there. The valve cover isn't the best location. Why not just use the stock DE-K location on the timing cover?

 

lights dim= ground
cold start issue= iacv

 

What does cooling lines going through the TB have to do with start ups. Have you tried opening up the TB Plate slighty to compensate for cold starts. I would also just double check the IACV to see if it is properly functioning since your still using the 4th gen.

 

coolent lines going thorugh the tb. well let see. nissan came up with it to keep heat the tb when its cold. your coolant warms up and so does your tb.

 

i definatly had a feeling it was the iacv, but how do i fix it i mean the only thing i didnt do was hook up the breather hose fron the front valve cover to the intake piping. Why would the iacv start fine on warm but have trouble on colder days? Is there a solution ? The iacv is immaculate.

 

I see there is one smart reply in this thread..

 

There are many guys with the Coolant Lines Bypassed with no problem. I think your problem is somewhere else. Also consider that the Coolant is probably still cold once your problem is disapates itself out.

-matt

 

im pretty sure that the coolant for the throttle body is only for exteremely cold weather it serves as a precaution.

 

i know that. my coolant line through the tb is also bypasses and i dont have any problems either. its only needed on very cold days but then it isnt something that would make the car work any different if it is bypassed

 

Coolant going through the throttle body only serves two purposes:

1. Keep the throttle plate from freezing in extreme weather conditions

2. Allow the fast idle cam to close the throttle when the coolant temperature is warm.


Based on these two things, no coolant flow through the throttle body changes nothing at cold start-up, since no coolant = cool coolant as far as the fast idle is concerned.

 

ok and why are you telling me this when i already know?

 

Based on post #7 i wasn't so sure. Fair enough...

 

I asked that question about the coolant lines b/c I have read about the "BY PASS MOD" and like some have quoted it has very little use. Even in CT on a cold day it would be a rare situation in which DCMAN's TB Plate would freeze to a point of not allowing any air from going through.

Try Readjusting the throttle plate screw.