92 Prelude Satrts but won't stay running unless i keep my foot on the gas...
 

I just bought this car yesterday and when i test drove it, it ran just fine, it died once getting off the highway, but i though maybe it was just low on gas, so i filled it up with premium (the previous owner used regular unleaded). This morning when i went to start it, it started right up and idled rough and died. i can keep it running if i keep my foot on the gas pedal and i can even drive it. I made it to work and it died a few times stopping at stop lights and getting off the high way. it seemed once it got a warmed up a little it didn't die as easily. The car did did have a motor swap and now hasw the 2.3 Si motor in it. It has a lot of after market parts on it as well. Any advise or tips would be a lot of help. Thanks Brian.

It sounds like you may have a bad EGR valve. I had the same exact issue in my old '91 MR2 in which the car would stall unless I applied throttle upon start-up. Here's how you would test the EGR valve in order to determine whether or not it's bad:

1) First check that all vacuum lines and electrical connections are in good condition.

2) Disconnect the vacuum supply hose to the EGR valve and connect a hand vacuum pump to the valve.

http://www.hondapartsnow.com/diagram...ice-461186.png
*diagram courtesy of hondapartsnow.com


3) Start the engine and allow it to reach normal operating temperature.

4) With the engine at idle, draw a vacuum on the EGR valve. The engine should stall (or run very rough) and the valve should hold vacuum. If not, replace the EGR valve.

5) Connect a vacuum gauge to the vacuum hose from the control solenoid valve; there should be no vacuum at idle. If there is vacuum to the EGR valve at idle, check the wiring for the control solenoid. One wire should have 12 volts anytime the engine is running. The ground wire goes to the ECU, which modulates the control solenoid opening by controlling the ground circuit. Turn the ignition switch OFF and use a digital ohmmeter to see if the wire between the ECU and control solenoid is shorted to ground. If the wiring is OK, the ECU is getting an incorrect input signal or the ECU is faulty.

6) The vacuum going to the control solenoid valve should be about 8 in. Hg (200 mm Hg) at idle. Connect a vacuum gauge to the hose coming from the air chamber. If the vacuum is not correct, read the vacuum at the CVC valve outlet. Full manifold vacuum should be available at the CVC inlet. If the air chamber or CVC valve is are not functioning properly, the units must be replaced.

Good luck man! :)