SR cold start problems

[Supafly]

ok, i've searched and not found any kind of concrete answer to this question.

i just finished swapping the SR into my 93 coupe. when i first bumped the key the thing started up and idled beautifully. went and drove it, all went well, drove well, came back to idle well.

i got in the car the morning after i originally drove it, it was pretty cold out ~35 degrees and it just didn't really want to start. it would bump off here and there but never catch until after i've turned it over for a minute or two (short bursts). so i played a little and found that if i hold the throttle wide open and crank it about 2 times then bump the starter it will start after a few seconds and bring itself up to idle. after that the car runs great, it seems as if the cold start idle is working because it does initially idle high and drop down as it heats up, and during driving the idle drops back to ~850 as it should and everything about the engine when it's running is perfect. it just seems as though it's not getting the extra fuel at startup that it needs in colder weather, but i can't really figure out what controls that on this engine. i originally thought it was a bad coolant temp sensor, but the car runs perfect after it finally starts (i don't have the stock gauge working to confirm/deny this at the moment, i wired the wrong half of the plug onto my harness so i have 2 male plugs for those, but will be fixed very soon when i can go hack a KA harness at the junkyard). if the IACV were bad it shouldn't idle right when the engine is still cold but running, or at least that's my past experience with a problem like this. so i'm stumped

can anyone shed any light on this subject?

[NISTECH]

its actually oppisite of what your thinking.. the car is actually getting to much fuel for the air it is receiving. Meaning you probably have a dirty throttle body or an improperly adjusted base idle setting. Once the car is warmed up. shut it down and disconnect the tps. Restart it and make sure the base idle is at around 750 rpms. After you get it set shut the car down reconnect the tps and restart it. when you started it with the tps you should find the idle extreamly low. This would have been your cause for the no start. As you mentioned as well the coolant temp sensor could cause a hard cold start as well if it has high resistance. And this sensor is not the same sensor that runs your gauge.

[Supafly]

excellent information, thank you NISTECH. where is the coolant temp sensor located that controls the actual ECU funtions and not the gauge? or better yet i'll just try to find a downloadable FSM on here to locate it. i'll try this and see if there's any result.

[NISTECH]

it should be somewhere near the t-stat housing. 2 wire connector most likely red or yellow connector.

[Supafly]

it should be somewhere near the t-stat housing. 2 wire connector most likely red or yellow connector.

any idea on the wire colors? i found a link with the SR FSM but it locks up the computer every time i try to get to it:(

[NISTECH]

give me the link. I'll give it a shot. I am not familier with the sr20 wiring harness.

[Supafly]

http://69.56.142.114/%7evideof...M.pdf

[NISTECH]

I have the manual up right now and am going through it when i find the colors I will post back.

[NISTECH]

here you go

[Supafly]

i just had a chance to go look at the car, i found the sensor, just behind the water neck. thanks again NISTECH. i'll do some tests today and see what i can find.

[NISTECH]

i am in the process of downloading the FSM to my comp so if you need any other info from it let me know.

[Supafly]

thanks again man.

[Supafly]

UPDATE:

without touching a thing, the problem is gone. i went out in the morning to work on it, key on, clutch in, fired right up. hasn't skipped a beat since

i'm guessing something was sticking or had buildup on it from sitting and now that the motor's been driven quite a bit it cleared itself up. i seem to have a lot of luck this way lately