a few weird start-up issues

Pablo94SC

Registered User
These started happening recently and I figured I'd ask here to see if anyone else has had them.

1. Car starts but acts like it's running on 5 cylinders. A quick goose of the throttle and the idle smooths out.

2. Engine takes a good 2-3 seconds of cranking to start. Normally the engine fires right up after a couple of revolutions. Happens both warm and cold, and usually with 10 or more normal starts between.

3. Car starts and idles fine, but stalls after being put in gear (automatic). Sometimes happens 2-3 times before the car stays running.

I have a feeling these are all related somehow, but they have never occurred together. #1 and 3 happen pretty rarely, maybe 1 in 50 starts, but enough to take notice.

Plugs and wires tested fine, so those can likely be ruled out. There's no CEL or stored codes. Any thoughts?
 
get a fuel pressure gauge that mounts on the fuel rail and monitor fuel pressure leak down. I'm guessing a fuel injector may be leaking leading to a wet cylinder at re-start.

The engine stumble and die may be due to issues with throttle plate adjustment, idle bypass, and the IAC motor. If the car currently is using a bunch of IAC to maintain idle when it's running well, there may not be enough IAC to make up for the low power situation when you have a weak cylinder.
 
These started happening recently and I figured I'd ask here to see if anyone else has had them.

1. Car starts but acts like it's running on 5 cylinders. A quick goose of the throttle and the idle smooths out.

2. Engine takes a good 2-3 seconds of cranking to start. Normally the engine fires right up after a couple of revolutions. Happens both warm and cold, and usually with 10 or more normal starts between.

3. Car starts and idles fine, but stalls after being put in gear (automatic). Sometimes happens 2-3 times before the car stays running.

I have a feeling these are all related somehow, but they have never occurred together. #1 and 3 happen pretty rarely, maybe 1 in 50 starts, but enough to take notice.

Plugs and wires tested fine, so those can likely be ruled out. There's no CEL or stored codes. Any thoughts?

I had very similiar issues with my car. It turned out to be the TPS was adjust too low (around .85 volts at idle) where the sensor was very inconsistent. It would bounce anywhere from .8 to .94 with the throttle closed. Adjust the TPS to .96 volts and it has been fine since...
 
I was thinking injector may be leaking or not spraying properly. DD also mentioned it could be a tad bit too rich/lean on start up causing it act goofy at times. He wants me to monitor my plugs and send him pics if I notice anything out of the ordinary.

I thought about the IAC but didn't hear the honking goose sound so put it out of my mind. I'll need to check the throttle plate adjustment and check the TPS voltage again to see if it's gone out of range since I last set it (talk about a pain).

Thanks for the tips guys. Gives me a couple places to start looking... and gets my ~~~ in gear to order a gauge for the rail.
 
To check IAC all you ned to do is pull it off and look inside. You can see if the plastic is broken or not.

Without the rail gague you can check for injector leakdown by pressing down on the shrader valve. This and the fuel gague test isnt the best as you can also be loosing pressure at your fuel pump.

Stumbling once started can be a rich condition or a lack of fuel issue. An in cockpit gague would be a better option to see whats up in that case.

And ultimately puling the plugs will tell you if your having a rich issue in one cylinder.

I'd say pull the plugs and if your going to get a gague..Get an in cockpit one
 
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