Adamant1971

Car is still driving but a loss of power above 3k. Me thinks it's the flappy. No way to pressure test it. If you rev it past 3 when parked, will it move?



Just outside of Roanoke, having a bite.

I guess i will just drive her easy and check under the hood more often.

Leon Speed

I doubt the flappy can cause serious power loss. Maybe torque but not serious. Anyway, it should move after 3.5K revs, it should also open and close as you turn on the ignition. If you take off the rubber cap and attach a piece of tape, you can look under the hood from behind the wheel to see if it moves.

Have you tried switching some 53B relays?

Serious power loss above 3K revs sounds more like a bad MAF or LH. Or fuel restriction, or bad fuel, or incorrect timing, or corroded ignition coils.

Luckily you can cruise easily at 2.5K revs.

Adamant1971

Maybe the power loss is not as serious as I first felt.

Pretty sure the flappy is not moving, I already had the rubber cap off and revved her up and it did not turn.

I will try the tape, so I can see where the tach is at.

It's still accelerates above 3k, just not with the unusual freight train feel.

mickster

My cars flappy is disconnected; power loss compared to other S4s is not huge in comparison driving.

Adamant1971

Tested with a piece of tape, flappy is not turning. Will carry on towards Pittsburg.

Adamant1971

Tested it again,I just gives a very slight twitch. Will need to test vacuumed lines, and the flappy system at home.

mickster

Ah-yup. Could be symptom of large vacuum issue. Safe travels!

Mrmerlin

how much fuel is in the tank? better to run it at half or more

did you remove the gas cap to check for suction?, leave the cap half a turn loose.


did you look at the tank to see if it is collapsed? check the vent valve adjacent to the dipstick this goes bad the tank will collapse.
leave the cap 1/2 turn loose

M. Requin

If I am in range and you need help- 434 eighttwothree 2059

James Bailey

It is NOT the floppy...I would be concerned it is running on four cylinders....so you have 160 horsepower

Tony

sounds like its timing related..

James Bailey

Timing related is a big potential problem..... huge unmetered air leak is worse at low RPM. Fuel filter blocked is so uncommon...
The cars will run surprisingly well on just 4 cylinders. I would be checking both ignition systems

dr bob

Check that the secondary leads from both coils are secure in the distributor caps. If you were recently in the MAF area, verify that the MAF is seated in its boot correctly. Change the fuel pump relay. Verify that the battery voltage is OK (not falling off due to discharge). Verify the connections of the minor positive leads at the battery, clean and tight.

The flappy makes only a very minor drop in power if not activated. It's connected to cannister/stored vacuum, so you should feel real vacuum at the source port on the flappy solenoid with the car idling. Regardless, effect is minor and generally ot a sharp difference you might notice in casual driving.


If one ignition is not working, raw fuel is passed through to the cats. That's a serious risk of fire. Might be coil leads as shared above, arcing from a bad wire, failed transistor driver module on the front apron, or a failing coil, cracked cap.

The symptoms also sound like some that have reported as part of an impending total LH failure. Is yours rebuilt?

Adamant1971

It's seems to be running better, just outside of Pittsburg now.

I'm leaning towards it being fuel related. I'm going to stop shortly for the night. I will check the gas cap and the ignition leads when I get to a hotel.

I'm wondering if it could have been some bad gas?

Anyways thanks for the tips on what to look for.

Adamant1971

No, the LH was not rebuilt, but it is a used unit that was put in the car back in the late 90's.