jcg928s

Hey guys,

My name is Joey. I finally got my childhood dream car, a Porsche 928S. I guess it must have been too much Weird Science or Risy Business as a kid maybe, LOL. Anyway, just wanted to say hello and I will be lurking on the forum daily always learning.

I got her on Tuesday. She is BONE stock. I have fixed a few bugs here and there. I have ordered a window switch, sunroof switch, replaced a seat switch, fixed a door pin and am looking at raising her up a little (New Orleans streets are bad). I have a coolant light, but its the float sensor in the expansion tank, which is supposedly harder to find than Jimmy Hoffa, LOL.

Only thing I cant seem to figure out is this miss it has. Its strange. You can barely hear it at idle, but if it is under a load its much more noticable (Meaning between 1500-2500 RPMS). I am a pretty good wrench turner (I have built quite a few cars), but Im not sure where to go with this one.

I started diagnosing by letting it idle and pulling one plug wire at a time until I didnt hear a change in idle. I got 4 down, I will the other 4 more tomorrow. I did hear a change in idle slightly with each one I pulled, then put back on. If I can figure out what cylinder it is, I think I can try (new plug wire, new plug, new injector).

Or if anyone else has any ideas, I would love to listen.

Worst case scenario I will have to bring it to Greff Motors here in New Orleans for them to fix. However I have never had to bring a car to a mechanic before. I usually diagnose it myself after research and reading, however for some reason this car intimidates me, LOL.

So, without further delay, here she is......

1984 928S 5spd, original paint, original interior, etc.....











I was in the process of removing the radio, hence why it is sticking out.


Anyway, just wanted to say hello to my fellow Porsche Brethren.

White Lightnin'

Welcome to the shark tank!

EspritS4s

Congratulations. I won't speculate on the miss, but it looks like a beautiful 928. The exterior looks to be in better condition that the interior, which is rare for many parts of the country. Regardless, the car looks great. Good luck with sorting out any mechanical problems.

Nicole

Congrats! It appears to be in exceptional condition for its age. How many miles on it?

You may want to add the location as well as a signature with the model year to your profile.

riviera455

nice 84,, how many miles? it looks realy well preserved,

mine is an 84 to.
it has been repainted verry nice by the po.
i have replaced the waterpump and timingbelt and untill then only had to replace the alternator.

your problem can be ignition, i would start with a new set plugs cap and rotor and see wat happens. its the cheapest way and the most suspected .

linderpat

Wow, that is beautiful!
As to the idle issue, the most frequent cause is a vacume leak - look for that first, before throwing money and parts at it. Do a search through the wealth of resources for the vac diagrams for your car/year, and start working thru the vacume lines to see if there is a leak somewhere. Also, get in touch with Landseer (Chris) he is a frequent poster and has several of these early S models (red too!).
I love your car.

jcg928s

Hey guys!

Thank you for the kind words, yall are awesome.

She has 116K on the clock.

I have a bunch of receipts of services that have been done through the years. When I purchased it from the gentleman, he informed me that it couldnt have a miss because it left perfect. I want to believe him, but I am skeptical.

I took a small video of the idle. Instead of grrrrrrrrrrrrrrrrrr, its a kind of grrrrbupbuprrrrrrrrbupbuprrrrrrrr. If that makes any sense whatsoever, LOL.

Like I said though, it idles normal. short of the little miss. The miss is more noticable if you blip the throttle. instead of vrooooooom (Nice and smooth), it kind of stalls a little bupbupvrooooom. Geez, I sound silly. When under throttle while driving in the lower RPMS its much more noticable.

Sigh....... I will try and keep reading on things to check. The wires do look old, I may try a set of them.

Anyone else have any thoughts?

Nicole

Can't help you with the idle, but great that you added the location to your profile. To add a signature with your name and the model of 928 you own, click on "User CP" at the top left of this page, and then select "Edit Signature".

This will make it much easier for us to address you properly, and to know which model year your questions relate to.

Welcome to rennlist!

sty3x

That is one nice 928

safulop

Score, dude! What a great looking red 928. We like to talk prices around here, so if you're not shy I know many of us are very interested to learn how much for the bad girl. There have been a number of recent discussions about value versus condition etc., and that car looks very clean indeed. I'll let experts weigh in on the misfire, but an obvious suspect would be ignition stuff, which you would probably still hear on the road at cruise if it were misfiring.

-Sean

danglerb

I can't quite tell from the picts, is it a non sunroof?

Best way maybe to approach a minor miss is to do all the normal maintenance, grounds, etc. and see if it doesn't go away.

*** Make sure all your rubber fuel injection lines are in top shape as a first thing.

Landseer

Welcome.
That's in nice shape!

The miss is probably something simple. So here are the low-impact things to look for. If it doesn't fix it, we've got a longer list too.

Look for vac leak, esp. at distrib advance. Hose sometimes comes off or is flip flopped onto wrong port on back of throttle body.

4 ground points to clean asap: 2 above fuse panel. 2 on passenger cam cover ( 1 is completely hidden under the valve for the emissions air pump --- remove the hose/valve/tubing to get at it ). The ones on the cam cover are for the brain and engine electronics sensors including oxygen.

Clean the little hot lead at the battery / it feeds the panel.

Also, might be good idea to replace O2 sensor, another source for miss especially at load. If you disconnect it at the CE panel and the miss goes away, it could be non functional. Car will run without it but just doesn't trim-out the mixture.

I like to pull the CE panel out, polish it, replace all fuses and certain mission critical relays as preemptive work (after chasing problems for months on my first car). Use a real VW fuse, not the Buss version (inconsistent length / poor electrode design)

Dan87951

wow that looks clean!

cold_beer839

One little trick to check condition of ignition wires is to pull the car into the garage, close the garage door and turn off all lights (you want total darkness). Then open the hood and start the engine. You will be looking for sparks jumping from the ignition wires indicating they are bad and need replacing.

jcg928s

Hey guys,

Thank you again for the kind words, I feel very fortunate that I have my Porsche family to talk to when the mistress acts up.

Ok so here goes.......

Safulop: I dont mind sharing at all.....as long as people can keep the laughter to a dull roar if I payed too much, LOL. I got her for 8,000.

danglerb: yeah, the pics dont show, but she does have a sunroof and thank you for the tips.

Lanseer: WOW! Great list to knock out. Thank you!.........silly question though, whats the "CE" panel. (Runs and hides under a chair from embarassment)

Cold_beer839: Ya know I thought of that last night. I didnt see any arcing from the wires, but I will check again tonight.

Everyone else, thank you again for the compliments. Once I get the miss figured out, it needs some kind of exhaust. Its dead quiet, I mean REAL quiet. Maybe an RMB or something to start. Nothing too obnixious.

She will only get better with time though. For some reason I cant leave cars alone. I'll post some of the other cars I have built through the years.