KA24E Issues. Cold/Hot Start, Bogging.

[TonyToniTuna]

I have a 1990 bone stock single cam. It has starting and running issues. When the engine is cold and fairly cold outside, It takes multiple times for the car to start. I have to sometimes pump the gas in order for it to struggle to turn on. When it finally starts it has a very very low idle around 500-700rpm give or take (cold).
Once its warmed up the idle rises a little to around 800 and will SOMETIMES drive fine without any bogging issues. If i cut the car off when its hot and attempt to turn it back on It will struggle to turn on, have a rough idle for a few seconds, and cut right back off.
If i attempt to give it gas when trying to keep the rpm's up, there is a little lag from when i step on the gas to when the rpm's finally rise up.
There is also a weird problem where if I attempt to give the car gas...the rpm's will drop quickly and the car will act like its about to die then catch itself.

The car actually died on me at a light when I went to pull off from the light I stepped on the gas and the rpm's dropped and the car died and would not cut back on for about 5 minutes.

I replaced the CTS sensor but I noticed earlier that if I wiggle my CTS sensor harness wire my idle seems to change somewhat and I can hear a "click" from the engine? Could that be the culprit to all these problems? or is it something else? Like TPS/IACV??

[Frank_Jaeger]

Since the car is fuel injected, you're not giving it any gas by pressing the accelerator. You are opening the throttle plate, which is helpful if the IACV is clogged or malfunctioning. It's also helpful if you're running rich.

Here's a thread I made several months ago: http://zilvia.net/f/engine-tech/471770-need-hold-accelerator-start-ka24de.html

I never solved it, lol. Honestly I suspect my fuel pump has been on the way out for some time.

[TonyToniTuna]

Well yea I know it isn't giving it any gas since its fuel injected lol. Yea I had IACV on my list of things to clean.
But like I stated, if i wiggle my CTS plug harness wire my idle seems to change and the engine will make a "clicking" noise?
Is this causing the car to run in open/closed loop depending on how I flex the wire?
Could that just be the culprit to all these issues?

[Frank_Jaeger]

Take a video if you can of the clicking.

[TonyToniTuna]

It's a pretty straight forward click lol. Plus, I don't have any video recording device as of right meow.

[racepar1]

First of all check to see if your throttlebody is VERY dirty. That can cause a hard cold-start. Also the AAC valve is known to get clogged up. That's the valve assembly at the BACK of the intake mani, not the one on the side. The IACV ,on the side of the mani, will not get plugged up and doesn't really control your idle. Replace the connector for the coolant temp sensor as well as they're known to corrode and lose connection. When you've got a coolant temp sensor issue it can cause all kinds of issues so this is VERY important. For the bogging issue I would start with checking the TPS function and the MAF connections. The MAF connections are known to corrode, loosen, and the wiring can short under the rubber boot. Check for all those issues and tighten up the pins.

[TonyToniTuna]

First of all check to see if your throttlebody is VERY dirty. That can cause a hard cold-start. Also the AAC valve is known to get clogged up. That's the valve assembly at the BACK of the intake mani, not the one on the side. The IACV ,on the side of the mani, will not get plugged up and doesn't really control your idle. Replace the connector for the coolant temp sensor as well as they're known to corrode and lose connection. When you've got a coolant temp sensor issue it can cause all kinds of issues so this is VERY important. For the bogging issue I would start with checking the TPS function and the MAF connections. The MAF connections are known to corrode, loosen, and the wiring can short under the rubber boot. Check for all those issues and tighten up the pins.

Excellent. Thank you. I cleaned out my Throttle body few months back. I'll attempt it again. I will also check MAF and TPS and report back.

So I'll just take this entire assembly off and clean it then.

http://i74.photobucket.com/albums/i257/bigjohn151/iaams8.png

[racepar1]

Excellent. Thank you. I cleaned out my Throttle body few months back. I'll attempt it again. I will also check MAF and TPS and report back.

So I'll just take this entire assembly off and clean it then.

http://i74.photobucket.com/albums/i257/bigjohn151/iaams8.png


Exactly, take it off and all apart and clean it out. Be careful not to lose any of the little pieces and remember where they go back. It's not very complicated you just have to be sure to pay attention when dis-assembling it. The screw on the side of it is your idle adjustment screw. After cleaning let the engine get COMPLETELY hot before any adjustment is made. Rev the engine between adjustments just to be sure it returns to the same idle. Make sure to check the electrical connections like I mentioned as well. Those are super common issues...

[TonyToniTuna]

PROBLEM SOLVED



Sorry for the very long absence. I finally fixed the issue. I didn't even pull off the IACV to clean it or anything. Since I knew that if I wiggled my coolant temp sensor wire the cars idle and drive ability would change and act normal, I decided to just go ahead and cut the old coolant temp sensor wires and pigtail off and wire in a new one.

Once I wired in the new one the car starts right up and does not struggle to stay on or have any of the problems I was having before. I can freely give the car gas now without it attempting to die. I can also hot start the car now without it also cutting right back off like my previous issues.

Here is the old Coolant Temp Sensor wire I cut off. You can see how the female contacts are a bluish/green color front and back. nasty.
EDIT: sorry for the horrible focused pictures.

http://i.imgur.com/yMWMt6Y.jpg
http://i.imgur.com/O30cFvx.jpg
http://i.imgur.com/Q5wgl6X.jpg

I hope this helps anyone having the same issues!!

[frytryout]

right now,It's a pretty straight forward click lol. Plus, I don't have any video recording device as of right meow.thankshttp://www.maxin.us/imax/images/3.gif

[KiLLeR2001]

I would urge anyone who is having issues similar to this to check their ECU for code 13. Even if your car starts but is taking forever to start, it could be in indication of something wrong with the CTS circuit. If you replace the CTS and the code still comes up, most likely it will be the wiring closest to the engine that has gone bad giving improper readings.

I replaced my CTS, swapped out another ECU, but was still getting code 13. I decided to replace the pigtail and the wires going to the sensor itself and problem now solved.

[wangan_cruiser]

Good stuff. where did you buy the new connector? i tried to search it but i cant find.

[TonyToniTuna]

I just cut off a pigtail from another single cam harness and cut and wired it in. I bought the actual Coolant Temp sensor from Autozone.