Idle problems with a 245

AMM is simple to check.

While the engine is running, disconnect it. If the engine idle changes, that's one sign. The other sign of a failed AMM is if you quickly do a mini-throttle while the AMM is disconnected, it usually comes close to, or will stall.

Have you checked your flame trap, and throttle body for dirt? How about your air filter in the airbox? I'd be checking for low air flow first in these situations.

Rob Kitchener, ON, Canada

Wed, 9 Jul 2003 14:19:35 -0400, snipped-for-privacy@nospamsympatico.ca suggested: : AMM is simple to check. : : While the engine is running, disconnect it. If the engine idle changes, : that's one sign. The other sign of a failed AMM is if you quickly do a : mini-throttle while the AMM is disconnected, it usually comes close to, or : will stall.

I don't think I understand. Wouldn't the behavior with the AMM disconnected be the same whether it had failed or not?

Make sure your base idle is correct. You can ground the CIS (constant idle system) so you can set the idle. There's a connector near the firewall connected to a blue/white wire. Ground the wire and the CIS system will be overridden so you can set the idle.

Check your injector seals for vacuum leaks. When cold (and/or hot) spray carb spray on each injector; if the idle changes your seals are leaking. The seals can leak when the car is cold but seal up when the car gets hot. If the idle problem goes away when the car is warmed up I would suspect vacuum leaks from somewhere.

Check the car for vacuum leaks. The vacuum at idle should be between 16 and

Make sure the ignition timing is set correctly.

Make sure the CO is set correctly. A too lean setting will cause stalling. As a test, disconnect your O2 Sensor and see if the idle problem goes away. If it does then your car is probably running too lean. Sometimes the O2 system will pull the CO too low when connected.

Brick_0

Changed the fuel pump relay with a known working

Thu, 10 Jul 2003 16:52:16 GMT, snipped-for-privacy@home.com suggested: : if I read the messages in the thread correctly, the car was running OK, you : had the air filter changed, and shortly thereafter it began to have the : problem? If so, I'd first think that the connector to the AMM might have : been knocked askew during the filter change, and finally worked itself loose : enough to cause the bad running. With the engine off, try removing and : reconnecting the connector to the AMM several times, leave it connected, and : see how the engine runs. I do this periodically on mine, whenever it : develops a rough idle or lacks power on acceleration, and it seems to fix it : each time!

That sounds like the contacts are oxidizing. You might try shooting a good contact cleaner on the pins for the connector next time you do this and see if it holds up longer.

been there, done that, didn't help much, but didn't hurt either! Used PROGOLD, a contact treatment that I've been using on other electronic/computer connectors for years, generally very good.... Since I only have to "work the connector" a couple times a year, that's an easy/cheap fix.....

AMM connections going bad? Seriously? My thought at that point is the wiring harness is going bad.

I also had a problem with starting / rough idle in damp weather. The electronic advance component that enters the distributor at the front of the distributor had a broken mounting point, resulting in water getting thrown into the distributor by the fan.

If idle was OK then all of a sudden not, the AMM connector not being seated is one thing, but I've also heard from other folks where cracks in the air intake tubing resulted in poor idle / engine performance.

Too me it sounds like an air / vacuum leak occurred. OH WAIT! I had rough idle also start once when the rocker cover bolts became loose (long story on that one). I tightened them down and it smoothed out, but I don't suspect that's what's happening here.

The flame trap is located dead center underneath the intake manifold in the middle of a Y splitter tube that enters the engine head/block. Hard to see from a-top, but you can feel it with your hands.

Rob

Actually, the base idle can get screwed up if the throttle linkage is worn or broken. I had a problem where the spring clip was pretty worn from maintenance disconnection and it had free play, which resulted in unstable idle. Normally the idle switch should trigger the ECU to set up the idle speed, but occasionally my 'idle' ran high.

Throttle body dirt is another source of bad idl> No, you cannot set the base idle or timing on that car.