82 928S euro running weird and making strange noises

[EIPtuningR32]

I have a 1982 928S euro and i have recently changed the ignition wires and spark plugs. before i go into detail.... i know for SURE that the wires are in the right places... ok. so the engine was running fine before changing the ignition wires, but after i changed them, the engine runs REAL rough everywhere except idle. at idle it runs ok but only from the exhaust do i hear this noise that sounds like someone banging a plastic sprite bottle on concrete. if i rev the car, it will backfire. now i know it sounds like i screwed the wiring up but i know everything is where it should (except one wire....but thats on a different forum). please..... any ideas would make me griiiiiinnn.....

[Danglerb]

Random thoughts;

The wires are messed up, wrong plug, or maybe just crossfire between wires.

One of the internal wire parts is making a bad connection, or one of the resistors in the plug insulator is bad.

Vacuum line dislodged during wire change.

Wire (not a spark wire) messed up during wire change.

[american-kiwi]

did you look at the numbers-to plugs on the cap "before" you pulled the wires?...PO might of had the dizzy pulled and timed at a diff' setting...re: cyl-1 becomes cyl-8 or cyl-3 etc...or did you bump the dizzy...and throw the timing out?...but like Danglerb says...sounds like a vac' hose could be off somewhere...runs fine at idle...them backfires under load...throwing the timing out with no vac-advance...John

[rhjames]

if it was running fine before the spark plug cables were changed, then now running bad, the new cables or their order are to blame.

no offense, but unless you removed and replaced each cable one at a time, you could have mixed them.

it happens.....I've done it I don't know how many times.


short of all that, remove #1 plug, bring to TDC, arrange cable to distributor terminal where the rotor is pointing to and connect the other end to #1 cylinder, and follow with the rest according to the firing order.


--Russ

[EIPtuningR32]

Originally Posted by rhjames

no offense, but unless you removed and replaced each cable one at a time, you could have mixed them.

--Russ

yeah... thats the thing. is i did do them one at a time. the wires are labeled with shrink rap. i looked at the distributor cap with the numbers on them and followed the wire to a spark plug and removed it and replaced it with the correct labeled wire.

[Danglerb]

Did you use a full set with new plug sockets in Beru wire?

Did you check the resistance of each of the plug sockets, and the complete wire?

Did you use the stock Bosch copper plugs, gapped correctly?

If yes to all three, then while you were changing the wires something else got messed up, vacuum hose, sensor wire, or injector wire.

[morriss]

I had a similar problem with one of my other vehicles. Turns out that I did not route the new spark plug wires correctly and they were arching over on each other. I bought a set of plastic clip separators, downloaded the correct routing scheme, and that did the trick.

[SolReaver]

Is it possible that you rotated the cap 1 wire clockwise or CClockwise?...Inverted a pair through Dyslexia? It has happened to me and pretty much anybody who does it enough times. I have gone so far as to neatly tag and label and number plug wires incorrectly. Have another set of eyes inspect and validate all ist in ordinung. You can try disconnecting the spark leads while the engine is running to see if it makes a difference. (MR. Safety says Don't electrocute yourself or others)

OK, IF you are absolutely SURE that the Zundfolge ist rechtig...Is it possible that the (new) plug wires themselves are bad? Try putting everything back exactly as it was before. (yes I am suggesting that you put the old wires on to test the new wires) If problem solved, replace 1 wire at a time to determine the problem child.

Could you have disturbed a finicky Green wire at either end?

[Niles]

Could you have disturbed a finicky Green wire at either end?

What is this infamous green wire? Where is it located? Is there a photo? Is it in every 928 (77-95)? Thanks.

[SolReaver]

"Green wire" runs from base of distributor to the (ECU? EZT?) (the ignition brain on the passenger firewall just forward of the engine). You have one. The connections can get flakey and the car runs like doo doo or not at all.

[EIPtuningR32]

Originally Posted by SolReaver

"Green wire" runs from base of distributor to the (ECU? EZT?) (the ignition brain on the passenger firewall just forward of the engine). You have one. The connections can get flakey and the car runs like doo doo or not at all.

holy sweet moses. i just recently when i was under the hood last night saw a green wire dangling and i said to myself, "man this is gonna be a pain to restore". ill take some pics and post them on here so you guys can help me out. I am 16 and i have really no reference of intelligence for this car. ill also upload a video of it running so you guys can see what I am talking about. thanks guys...

[SolReaver]

"boy is this going to be a pain to restore"
Yep! that is the one!

[MPDano]

Heres my write up on that Green Wire, complete with pics

http://www.porsche928forums.com/viewtopic.php?f=9&t=4&st=0&sk=t&sd=a&start=330

[EIPtuningR32]

First of all let me introduce my work in progress car.... 1982 Porsche 928S euro. its got an ugly exterior color that someone thought would look good, and a completely trashed interior. but....its got a dream engine.... until i changed the ignition wires.

yes those are the mark's wheels ROH Modena's. they are BEAUTIFUL. (thanks mark)

OK... here is the engine bay as of 3 minutes ago...

Here is my mess of wires that are messy because i had to route them to they would reach all of the spark plugs.

here is the loose green wire that i was talking about.

except it doesnt go to the ECM. it goes down the front of the engine...

then goes backwards towards the rear of the car...

then turns into the back of....

THIS THING.

here is where that "thing" is on the engine.


there it is on the left side of the engine.

there is also an extra ignition wire for some reason. it looks like the wire that was supposed to go from the ignition coil to the distributor but i already got one. this one is WAYYY longer though.

oh and i found the green wire you guys were talking about and it seems to be in place. but i have no clue where that other green wire goes that i showed above.
right into the back of the distributor.

thanks for your help guys and ill reply to your suggestions. =)

[MPDano]

Those pics are hard to look at. Maybe scale them down a bit. I usually use 800 to 1000 pixels.

[SolReaver]

Your green wire feeds into your alternator? Your AC compressor? What feeds into the Ignition Control unit? Oh man, I am way confused on this one. It goes INTO the distributor housing...Yes?...No. It seems to go into a temp sensor.... I THINK that is part of the AC circuit...But It shouldn't be green. put it on the to do list.

Hmmm. I think you have the wrong green wire. You just have a green wire. I was talking about THE Green wire. Look at the back of the distributor near the base. THAT green wire should snake its way to the Brain. check the connections (carefully)

BTW, the color is OK. I have seen one in metallic pink (eeeyuck!) The interiors are all trashed. Clean it and moisturise the leather few times and see what comes back.

[EIPtuningR32]

Originally Posted by MPDano

Those pics are hard to look at. Maybe scale them down a bit. I usually use 800 to 1000 pixels.

how do you scale them down?

[Danglerb]

Euro, but a non S right?

[EIPtuningR32]

Originally Posted by Danglerb

Euro, but a non S right?

nope. its a Euro 928 S.

[EIPtuningR32]

Also... if anyone could tell me what that "thing" is that i showed pictures of on the front of the engine would be great cause i need to buy a new belt for it cause well it doesnt have one!