'86 misfires/chokes at 2500 rpms?

[indy86]

I seafoamed my '86 635csi (110K miles) 6 days ago via the intake. I ran it hard the next day (only got a moderate amount of exhaust compared to when I was actually feeding it the seafoam). Normally the car is filled with octane 87. I decided to put a full tank of 92 along with a 1/4 bottle of seafoam. Yesterday I ran it while in park and it was pouring out smoke (like you would see after seaform intake). I revved the engine a couple times and would hold it at various rpm intervals (1200, 1500, 2000, etc). It was fine at 3000..but felt like it was misfiring (or choking?) when I held it anywhere btwn 2000 - 2700rpms.

-spark plugs were changed approx 4 years ago.
-plug wires are from PO.
-needs oil change (going on 10K miles) but can't get the filter off.

Is it plugs, wires, maf, ???

-indy86

any help or advice is much appreciated!

[carsnplanes]

I seafoamed my '86 635csi (110K miles) 6 days ago via the intake. I ran it hard the next day (only got a moderate amount of exhaust compared to when I was actually feeding it the seafoam). Normally the car is filled with octane 87. I decided to put a full tank of 92 along with a 1/4 bottle of seafoam. Yesterday I ran it while in park and it was pouring out smoke (like you would see after seaform intake). I revved the engine a couple times and would hold it at various rpm intervals (1200, 1500, 2000, etc). It was fine at 3000..but felt like it was misfiring (or choking?) when I held it anywhere btwn 2000 - 2700rpms.

-spark plugs were changed approx 4 years ago.
-plug wires are from PO.
-needs oil change (going on 10K miles) but can't get the filter off.

Is it plugs, wires, maf, ???

-indy86

any help or advice is much appreciated!

Can you remove the plugs and see if they are fouled or have an excess of carbon or maybe the Seafoam caused deposits of some kind. Since yo have Seafoam in the gas tank, youwill be pulling it through the injectors and the plugs will be burning it until all the Seafoan is gone from the tank.

By the way, you shouldn't rev the engine in Park and Neutral with an automatic.There is an issue with pressure build up in the forward clutchpak unless the Service Bulletin was applied.

[Zofryer]

Check every vacuum hose.

[av8r4aa]

NEVER EVER rev up your AUTOMATIC transmission in Park or Neutral.
These transmissions will not last if your rev them with out actually
putting a load on the tires.


EDIT:
Your oil filter has a canister that has a through bolt on the top.
it is not a spin on filter like you are thinking.
loosen the bolt on the top and drop the canister
down to the ground.

[alpinacsi]

If you do ever have to rev the auto in neutral make sure the car has first been switched off and allowed to settle a few minutes. Then start it up but DO NOT shift into any gears. Somthing about activating the pump when it is shifted and then when it is moved back to park or neutral the pump is engaged but no fluid is circulating and the a-pack clutches will be fried.

Best to just not rev it. The failures were experianced during A/C recharges and emission testing when the proper proceedure was neglected for the running in park.

[CW6er]

Here is the info from the service letter about not revving the engine:

http://bigcoupe.com/phpBB2/viewtopic.php?t=8437

I'd clean the plugs as a start.

[indy86]

well. I won't be revving it in park/neutral anymore. thanks!
-the oil change was easier than I thought (I'm used to the screw-on filter). I put Penn 10W40 in it (85 degree summer's here).

I'll be looking at the plugs soon. I hope it is as simple as that, but I think there's something wrong w/ the O2 sensors/cats.

I'll keep you posted.

[carsnplanes]

well. I won't be revving it in park/neutral anymore. thanks!
-the oil change was easier than I thought (I'm used to the screw-on filter). I put Penn 10W40 in it (85 degree summer's here).

I'll be looking at the plugs soon. I hope it is as simple as that, but I think there's something wrong w/ the O2 sensors/cats.

I'll keep you posted.

10W-40 is still way too thin. With 85 degree summers you need 20W50. I believe the owner's manual calls for that anyway.

[systemx29]

had the exact same problem. distributor cap was burned up.

[Brianl289]

Your oil filter has a canister that has a through bolt on the top.
it is not a spin on filter like you are thinking.
loosen the bolt on the top and drop the canister
down to the ground.

Lol, so thats how it works. I thought it was a screw on one and got so frustrated trying to spin it and it wouldnt come off.


Also, seafoam has been known to foul plugs. Check those. Also, when you put it into your tank. It may have loosened up alot of gunk in the lines or tank. Potentially causing your fuel filter to become clogged, or even the injectors.