Spyder 98 Mitsubishi Eclipse GST idle problems

[Summer_mccali]

Hey guys! This is my first car and I knew it’d be a project for its price .
Every time I turn it on, it drops to 0 rpm and shakes like hell. I can keep it at 1-2 rpm by holding the gas down, but I don’t want to drive it if its a serious issue.

I replaced the spark plugs and got notice it might be the idle air control. Any help or anyone who’s had this issue?

 

[idkiliketurbos]

Definitely check for any large vacuum leaks after the mass airflow sensor.

 

[spyderdrifter]

Do a boost leak test. That'll pin point MOST of the vacuum leaks. You will probably need to rebuild your throttle body, or at a minimum, replace gaskets and o-rings in/on it. The TB is notorious for leaks. Look around for old dry-rotted vacuum lines as well, a lot of them are on the backside of the TB/intake manifold area. Also check around the BOV. If you have the OEM 2G bov, it's likely to be cracked or leaking from the valve.

 

[bo0st2]

Yeah gotta be some sorta leak

any chance you got ECMlink? or any way to tune it?

 

[dwb]

STOP running the engine and make 100% sure the mechanical timing is correct and balance shafts are in phase (if not deleted). The timing belt can slip a tooth, run like garbage, but still be salvageable.

A leak between the throttle body and intake runners won't cause low idle. It causes high and erratic idle. Unlikely it's the IAC/ISC as that would cause high idle as well unless it was completely bottomed out and the BISS was bottomed out too. Even still, it's hard to get these cars to idle much below 650 even if you're trying.

 

[pauleyman]

UPDATES FOR THE OP
An update for today.
It will randomly drive fine, idle fine, have turbo boost then out of nowhere idle as low as possible, lose all boost, have no acceleration, shake like hell, and the the two spark wires to the right (drivers side) have no spark when pulled out. and sometimes it won’t even turn on it’ll crank for a second then just die, but then RANDOMLY be fine a couple minutes later.

 

[pauleyman]

Dropping two cylinders I assume this either the 1/4 pair or 2/3 pair which would mean you're dropping a coil. This does NOT mean you have a bad coil. You need to find out why it's dropping. Check harness, coil (prefereably when hot), ignition transistor, harness and finally ECU. ECU is a common problem on older cars when capacitors get old and start leaking.