88porsche928

I did something bad, i took my car to a drive through car wash "never again". anyways it cuts off "the wash had a car underbody wash". Its similar to a bad ISV problem you have to keep the rpms up. However, it only seems to have a couple of the cylinders firing. I don't think all 8 wear igniting. Ill do some more investigating tommorow. Anyways I noticed the relay under the ECU has a red light come on during the cut off. and when i hold the gas down to keep the car on it stays on. Any ideas? I can't even wash a 928 without breaking something FML.

88porsche928

also in case anybody cares I moved to middletown, ny. i think I have the only porsche and their is nothing out here

Tom. M

If you have the Ign monitoring relay..then your 928 isn't an 88?.. That started in 89..at least here in the US. You should be able to shut the car off, and restart and it should go back to 8 cylinders (for a while at least). This relay shows 4 cylinders being shut off due to temp sensors noting a difference in the two exhaust manifolds.

Give the 928 time to dry out and then see if it comes back...

76FJ55

If you got the engine bay significantly wet and your plug wires are old, you can get a lot of arcing through the insulation which will cause you to drop cylinders. open the hood with it running in the dark and see if you have a bunch of fire works going on in the engine bay.

88porsche928

its an 89 sorry (my user name came from my last 928). thanks tom m. You probably just saved me my next paycheck

AO

Check your coil wires. Mine did the same thing, and it was a cracked coil wire getting wet. I don't recall which side is red, but I think it is the passenger side. Good luck.

88porsche928

I believe when i put my car on a lift a couple weeks ago to change the oil i noticed thick red wires on the bottom, i am not sure what to check for, moisture? where do they connect to? do you have any pictures? thanks

ZEUS+

When the red light comes on the fuel injection pulses for cyls. 1,4,6,7 are shutdown. Hopefully just an igntion wire failure with the passenger side dist. or coil as Andrew stated.

Tom. M

The coil wires won't be red necessarily. The coils are located under the hood (top side) about midway along each fender. If you see both distributor rotors on the front of each head...look for a single plug wire under the bottom going to a round cylinder along the fender (both passenger and drivers side). pull the wire off the coil (cylinder) and check for water/corrosion...

P.S. The red that Andrew is talking about is the led inside the car...red is basically one coil and green is the other coil...each coil fires two cylinders on each bank (total of 4). When the temp sensors on the 4 and 8 exhaust port shows a big difference in temperature (caused by a bad coil etc..) it will shut off the fuel to the cylinders fired by that coil....

Shark_Week

sorry for the slight hijack. in that picture, what is that connector near the yellow circle used for

AO

I'm sorry, I should have been more clear. The red light means the passenger side coil/distributor is shut down. This is for Cyl 1-4-6-7. If a green light had been illuminated, then that wouldhave indicated the Driver side coil/distributor was shut down (cyl. 2-3-5-8).

The coil wire I'm talking about is the wire that goes from the coil to the bottom of the distributor. I would remove the wire completely and inspect for cracks. If it is cracked, you should probably get yourself a complete new set of wires. Yes, they are expensive, but the car will run better and you should be good to go for another 10-15 years.

Call Dave or Jeannie at 928 Specialists on Tuesday to order: 828-766-9280

Final note: You should not drive the car while it's only running on 4 cyl. This is bad for the motor. If you have to (maybe to get it a few blocks home) be gentle.

Stan.Shaw@Excell.Net

Similar to systems my GT still has, and I did recently notice it happened after rain and a car wash (both).

My car has very recent Magnecor wires in it. I am wondering if anyone has similar problems, and they are just not very good wires for the car....

88porsche928

i replace all the spark plug wires 2 weeks ago except 2 wires, the ones that connect to the distrubutor and the coil , it cams in a set of 10. the 2 new wires where hard to put on, ill try again later today

88porsche928

Alright here is the problem i ran into the wires that connect the two coils to the two distributors have different connections at one end. the orginal one on the left had the hole in the center of the pin on both ends. the one on the right the new one doesnt. should i just refund this or try to exchange the wires?
is this how the wires are supposed to be but mine is just messed up? anyways before i removed the old wires i started it up. it ran on 8 cylinders then went back to four after a minute.

Lizard928

One on the left is for 89 and newer, one on the right is 85-88