Car starts in winter but not in summer.. help

[khamul02]

For the last couple years my car will start up with one turn of the key in winter perfectly.
But in the summer or once we hit about 85 (in Mississippi that is now), my SC (81) is very reluctant to start. I can keep the key turned for 30 seconds (or longer) with the starter going and it won't start. I have to do that twice to get it going.

I thought accumulator (vapor lock) but this problem happens after a week of sitting around.

I'm all a loss.

[DRACO A5OG]

What is the voltage of the battery in the summer?

[ossiblue]

Be sure your ignition/electronics are in order before diving into the fuel delivery. The heat may be just enough to raise resistance enough to cause issues with the ignition or the DME.

[khamul02]

It is a new battery but I will give it a check. I did replace the alternator but this problem was happening before and after that replacement.

[T77911S]

i would check fuel pressures first.

[Bob Kontak]

Skip the 30 seconds. If you spin for that long AND the cold start valve is working the whole time (sprays when starter is turning) you have flooded it.

Check the Cold Start Valve sensor connections on the driver's side chain cover. 85 degrees ambient is getting closer to the sensors self cut off point (115F or something around there). A poor connection may hamper it's ability to make the ground needed to engage the CSV.

Another trick is to turn the key to "on" and lift the air sensor up for a second to get fuel pressure built in the lines. It helps if the CSV is not working.

[khamul02]

You guys have given me some good places to start. The thing that really puzzle me is how it starts perfectly in sub 80 degree weather.

[tirwin]

Originally Posted by khamul02

You guys have given me some good places to start. The thing that really puzzle me is how it starts perfectly in sub 80 degree weather.

It's CIS right?

[T77911S]

if it is getting too much fuel the really cold starts will be good. too much on the warm days is bad.

[DRACO A5OG]

Originally Posted by khamul02

It is a new battery but I will give it a check. I did replace the alternator but this problem was happening before and after that replacement.

Check the connectors too. I had a hair line split on my positive side and gave me such a headache.

[khamul02]

Thank you all for the help. Will report back after the weekend!

[sugarwood]

Bob, where is the air sensor that one lifts to build fuel pressure? Got a pic?

[khamul02]

Is he talking about here: http://i262.photobucket.com/albums/ii93/BellCityDubber/42292149.gif

[ossiblue]

Originally Posted by sugarwood

Bob, where is the air sensor that one lifts to build fuel pressure? Got a pic?

Take off the air filter and look into the intake or feel it with your fingers. Put you hand under the plate and lift slowly. The fuel pump should begin to run and pressure will build until you hear/feel the injectors shoot fuel.

[timmy2]

Get the wur cold fuel pressure measurement. Odds are it is too low.

[Derek911]

High Humidity. Condensation in dizzy. One of the most humid States in the Country.

[Bob Kontak]

Originally Posted by timmy2

Get the wur cold fuel pressure measurement. Odds are it is too low.

Good point. The dynamics of cold ambient and warm ambient change cold control pressure.

I still think it should run/fire with a functioning cold start valve, even if briefly.

Condensation in the cap is a good thought also. Even if 85 thru the day it is chillier at night.

[timmy2]

My thought is it is too rich when cold with the CSV and perhaps low wur system pressure. After 30 seconds of cranking the temperature of the tts rises enough and cuts out the CSV, leaning out the mix and it starts and runs.
Theory only, we need the complete set of fuel pressure readings to deduce more.

[khamul02]

How do I get the required fuel pressure readings? Is there a thread? I'm still a noob.

[tirwin]

CIS Troubleshooting for Dummies

See post #6