I have a 93 Shadow with a 4 cyl 2.2 motor. I replaced the head gasket this past spring and did a total tune up with plugs, wires, rotor, belts, hoses, everything.
The past few weeks, the car does not idle well at startup. When cold, the engine will not set at high idle. The engine will idle very slowly and flounder until you add some throttle. At this time the idle will smooth out and the car will run fine. This happens when warm also.
Now as the weather has been getting colder, the motor will start but will die immediatley. This will happen several times until the motor finally starts and stays running.
There have been no warning lights or check engine lights so it appears that no codes are being set. I am wondering can this be a vacuum leak of some sort or fuel related. Your help would be much appreciated.
Is it carbed, multi-port, or throttle bodied(tbi)? Let me know and I can help
September, 28, 2006 AT 10:21 AM
It is a TBI. I have changed a few things and the problem still exists.
I have changed the AIS motor, TPS and coolant sensor and the issue is still present. When the car warms up, it runs and idles perfectly. When the AC is turned on, the idle will increase to compensate for the additional load and all seems to work fine.
When vehicle is cold as in early morning or sitting all day, it is hard starting and idles very slowly at startup.
I took the air cleaner off to verify that there were no vacuum leaks and noticed a strong gasoline smell at the throttle body. I am wondering if the fuel regulator is a problem. Also, I found out that the MAP sensor also provides feedback to the AIS motor at startup, could that be sensing incorrectly. Any help you can provide would be great. Thanks
September, 30, 2006 AT 3:50 PM
Upon start-up you need a certain air-fuel mixture, more air than fuel of course, when the idle drops below normal and cuts off when no gas given means less air too much fuel, she will cut-off, my best bet check the maf (mass air flow sensor), it may be faulty and your computer may not read the code, or try calibrating or tuning the engine by ear, go to a parts store (advance auto), (i work there), and pick up a calibrating tool, it senses emmisions through the exhaust and lets you know your mixture, then have a shop or yourself fix the mixture
November, 6, 2006 AT 12:18 PM
Well. I am totaly lost. The car will not run at fast idle when cold. I have replaced the following components.
Idle Speed Motor
Trottle Position Sensor
Coolant Temp Sensor
Hall Effect Pickup Sensor
Fuel Pressure Regulator
The car will run very well when it reaches operating temperature. It will run fine when cold but the idle is very slow and need to feather the throttle to keep it running. I have checked and rechecked all vacuum lines and everything is perfect. I have checked fuel pressure and it is fine. I plugged another ISM into the harness and worked the vacuum line to the brake booster. The ISM moved in and out as the speed changed. It apprears to be working normally.
I do not know where to go from here. If anybody can give me some guidance would be greatly appreciated.
Thanks in advance.
November, 8, 2006 AT 5:54 PM
Like the guy said. Check the mass air flow sensor(MAF)
November, 9, 2006 AT 1:17 AM
Just an off the wall thought but were the timeing marks lined up exactly when you put the belt back on? Was it a new belt? I have owned 3 off these little shadows when teenager and if it jumps 1 or 2 teeth on the belt it will act this way