SR20 Cold Start Stall Problem

[tokarzni]

I have a redtop swapped in my '89 240sx. During startup the car will stall out unless I gas it. I have to hold the accelerator pedal down. If I let go it will take about 4-5 seconds before the engine dies out. It coughs hard and just stalls. Once the car is warmed up the issue dissapears and she purs nicely. Starting the car backup when the engine is warm is no issue.

Setup:I replaced the plugs (NGK coppers)Checked my vaccum lines for boost leaksCleaned the MAF (oem SR20 MAF)

I am venting my TIAL BOV to the atmosphere. Could this also be why at WOT on the highway the car sometimes bucks, and losses power. Laying off the gas just a little bit bypasses this problem.

Anyhelp would be greatly appreciated. I searched the formums and did find a few people with this VERY same problem but nobody seemed to post what the solution ended up being...

[CSUPUEBLOTIM]

How old is the gasoline in the car?

[roplusbee]

What condition are the idle controls in? I had a similar problem in my stock CA18DET. My issue was bad IACV, but I could not find a replacement. Just something to check......

[burntricer]

check your cas

[the converted]

I agree on checking the idle valves. There are two separate ones in the housing, one which is coolant temp dependent and another one that is electrically controlled.

As for the Stumbling when at wide open, the blow off valve probably is the problem. You should be using a waste gate that will hold a higher boost pressure, or adjust the pressure up if yours is adjustable.

[tokarzni]

Hey thanks for all the input guys. I just burned the remaining gas in the tank and refilled her with premium. Problem still persists. I know it's not the gas as I had this problem all summer. The car is now sitting in the garage for the winter but am able to take her out on days like this past weekend when the snow and salt are gone.

I haven't checked the CAS, CTS or the IACV. I will check them all to ensure they are correct as I bought the car with the swap already completed by a shop in Toledo and the kid from whom I bought it didn't seem to know much about it. I've already had to correct a few things so far.

Thanks for your input! Much appreciated, now if it would just warm up a bit in Columbus so I could work in my garage without a snowmobile suit on!!!

[japslapsilvia]

sounds like you coolant temp sensor is bad, replace it.

Then clean out your IACV.

[vanquish2]

Ok heres your problem....check pin 34 I think on the ecu....orange wire....

hook a voltmeter up to it and make sure that it is getting 12 volts when you turn the key to START....this should only see 12v when the start is turning.

This 12v signal tells the ecu to go into a "start map". When this doesn't happen it is a PAIN to start when its cold.....

If its not getting this signal and you want to repair it all you have to do is either hook it to a switch to goes to 12v and just flip the switch to off once the engine starts.......however, the best way is to find to correct wire in the ignition switch and make sure it is sending the signal to the wire......

check that wire and let us know......

I fought with this for 5 years and FINALLY fixed this a few months ago......

good luck!