Leaking Fuel Injector?

[GOFAST]

I have a '95 with about 9000 miles. It starts and runs perfectly except when I don't start the engine for a few days. After sitting for several days, the engine starts but idles rough for about a minute and then idles/runs normally. When driven daily, I experience no issues.

I believe that I have leaking fuel injectors which when not started leak fuel into the cylinders thus causing rough idle at start-up. I did recently replace the spark plugs and observed a gas odor in three cylinders.

What are your thoughts?

Thanks.

[scottfab]

Originally Posted by GOFAST

I have a '95 with about 9000 miles. It starts and runs perfectly except when I don't start the engine for a few days. After sitting for several days, the engine starts but idles rough for about a minute and then idles/runs normally. When driven daily, I experience no issues.

I believe that I have leaking fuel injectors which when not started leak fuel into the cylinders thus causing rough idle at start-up. I did recently replace the spark plugs and observed a gas odor in three cylinders.

What are your thoughts?

Thanks.

Stock injectors?
What is fuel pressure with key on but not started?

[Hib Halverson]

It's possible on a near-20-year old car that there are bad injectors.

Best way to start is with the fuel pressure test suggested by "scottfab".

Post the results. The procedure is listed in the Factory Service Manual.

[Paul Workman]

Cutting to the chase, I believe a leak-down test is being alluded to.

Connect a fuel pressure gauge to the Shrader valve on the front of the passenger side fuel rail,
turn the key ON to let the fuel pumps charge the rails. Pressure should peak around 52 pounds with the key on,
and then turn the key off. (Pressure may instantly drop to some value in the mid-high 40s, depending on the pumps used (i.e., the check valve characteristics).
monitor the pressure for several minutes.

You'd have to check the FSM for specifics, but in several tests I've done/seen, all is well if pressure holds to within a pound or so over 30 minutes.

If the system will not hold pressure, then it could be you have a leaking injector or two. And, it is possible the check valve(s) in the fuel pumps may be leaking too. Course, a wet plug or two would be a dead give away too!

P.