RJD2614

Hi all, so I just took delivery this morning of a 1985 928 auto car, in black, that is hopefully a "light project" car. I'm VERY excited! I've wanted a 928 for a long time, and have come around to them possibly being THE coolest design Porsche ever made. I wanted to both introduce myself(RJ, in Ohio), as well as get some feedback on what the best order of operations are on the car. Here's what I know about the issues with the car, from the previous owner:

-battery won't hold a charge
-catalytic converter was cut out of the car
-last drove in Oct 2020. was told he hadnt tried to drive since the cat got stolen
-car has been in a car port, so has technically been outside, but not subject to rain/snow/etc
-90k miles

My goal here is to get the car on the road safely, and then assess what I want to do, or not, in terms of restoration. The body is in ok condition-some peeling of the paint on the rear bumper, and the hood has a slight warp at one corner(the hinge doesnt open properly, but thanks to the search function, it looks like this is a common issue solved with lubrication). The hood struts are shot-I ordered a set.

I know that I need to replace the fuel lines, and the power steering hose. I am planning on an order from 928srus.com this week. In addition to those parts, what else would you suggest ordering now? Fuel filter/fuel pump? Should I drain the tank and replace the line at the rear wheel well? I hate draining fuel lines, so I'm inclined to just go ahead and shotgun everything now, if it's gonna save me time in the long run. I'll be doing most of the work myself, so I'd like to put my $$ into parts. I paid 5k for the car, so I think I have some wiggle room on parts before I get underwater on the car. I have a spare NIB cat laying around.

Another question: I generally never power wash engine bays on old cars, especially with carbs, but I wanted to ask here...is that an option? The engine is pretty dirty. I don't know if I'm risking getting water in the timing cover or anything in there. I can do it with a rag and a bucket if need be, but wanted to ask first. Thanks much for any thoughts on what I should replace/fix/etc while I have the intake manifold off to do the fuel lines.

Mrmerlin

I suggest that you dont put water on the engine .

I would use compressed air to get out the big stuff .

NOTE remove the air cleaner first and stuff a rag into the intake.
use brake cleaner on a rag to remove oil deposits,

NOTE anything with bearings in it will rust,
any electric parts can possibly fill with water.
wire harnesses and connectors will also do the same,
and then the engine may never run again.
Charge the battery,
use an IR gun to find the hot relay on the CE panel

RJD2614

Cool, copy that, thanks MrMerlin. This is the newest classic car I've ever owned, and wouldn't have ever thought of hosing down an engine before-this one's pretty bad-glad I asked!

I will be pulling the intake manifold to get to the fuel hoses anyway, so I'll do a gentle detail job for now, just to get it less gunky.

Any tips for removing intake and getting to the fuel hoses for replacement , or is it fairly straight forward?

khalloudy

Even though I fully agree with Stan, I have to admit I have done a quick wash on the engine here as the dust where I am turns the engine into a white bubble :-D I have tried just air blowing it and it barely made a dent. I usually make it quick then run the engine to dry it quickly after….

Mrmerlin

Use compressed air to blow out the sand on the injector bases and the edges of the manifold before you remove them

RJD2614

Thanks folks! Will it be obvious how far I need to tear down to access all the fuel hoses? Is there any other preventative maintenance that is easiest done with the manifold off? I don't know how well the car runs, so if things like spark plugs or anything else are not easily accessible with the manifold on. Love to hear what may be recommended while I'm in there.

Shark2626

Source your fuel lines through either your Porsche dealer, some new OEM lines are still available, or Greg Brown - Precision Motorsports. 928srus rubber fuel lines are inferior. Neither are anything like OEM, but if I had to chose I’d go with Greg’s.

But why are you avoiding starting the car? The processes of maintenance work you are about to undertake are warranted, and expensive, but don’t you want to diagnose why the car won’t start and then go from there?

RJD2614

Thanks, Shark2626.

So this morning, I did a full engine bay clean by hand, as well as the exterior, checked all my fluid levels, got a decent charge on the battery, and started the car. GEEEZ it's loud when it's blowing straight headers. Like, race car loud. Yikes.

So pretty much the whole dash lights up like a christmas tree. The oil pressure gauge, battery, and tach gauges all work. Either the car has no fuel, or the fuel gauge is not working-I get no movement at all at the gauge.

The car wouldn't hold an idle for more than 2-3 seconds. I did this 4-5 times, and at that point, the battery didn't have enough juice to crank the motor. So I've got it on a trickle charger, and I'm gonna put a gallon or two of fuel in the tank, and try this again tomorrow and see what happens. I did get a bit of a fuel odor at the engine bay, more so on the drivers side than the passenger side. Will report back when I have further diagnosis.

Petza914

I'd start with a new battery. That's going to make your life much easier as you go through the rest of your diagnostics.

Jim M.

Also the thrust bearing check. Very important with an automatic.

WALTSTAR

You sound like the perfect 928 owner. Handy and unafraid to dive in. The car will serve you well once you've gone through it. Get a fuel pump and filter as well as a timing belt, water pump, relays, and porkensioner. Welcome!

Mrmerlin

NOTE to charge any battery especially if its low,
use a 6 amp battery charger. for at least 4 hours.

NOTE a trickle charger is not a battery charger, it maintains what the charge of the battery is.
NOTE dont let the engine run so the alternator can charge a low battery, as this can potentially damage the diodes or regulator or alternator.

NOTE if you know you have a low battery either charge it properly or replace it.

NOTE starting a 928 with a low battery can damage the relays and either flood the engine or prevent the engine from starting.

This occurs because the battery will not provide enough voltage to close all the relays, this then causes the relay contacts to get dirty from the low closing voltage, not to mention powering the other systems to start the engine.

NOTE most likely you have original relays and thus have seen a long life of low voltage cycles.
its a downward spiral with a low battery.

Zshark

Pics pls

RJD2614

yes, pics! I keep forgetting. I'll try to get some better ones. for now here's a crude one, attached.

so i got a fresh battery in her today. the car fires, and a few times i got it to idle around 2k or so for about 3-4 seconds. that was as long as i could get. each time, regardless of how much throttle i gave it as it started to die, it would die out. i did this maybe 6 or 7 times. most times, it dies almost immediately. this was with a few gallons of fresh 93 octane in it.

i think the fuel level sender must be shot. the needle still didnt budge after adding at least a gallon or two. not a bid deal; i wanna get her running first. any ideas on my next steps? as stated, i am going to do the fuel/vacuum/PS hoses anyway, and likely address any electrical/spark upgrades anyway. would love any advice on where to proceed next.

Shark2626

You can start a new thread describing what’s going on to maybe get more eyes on it. Everything that comes your way are best guesses, but one of them is bound to eventually be right.

With a 928 the relays are always suspect, they were mentioned earlier in your thread. Relay relay relay is actually a saying here regarding the 928. The one ending in 53b seems to be used in your key spots, and there are a lot of them in “not so key” spots that you can swap in to see if they do the trick. Test each in the horn slot, also mentioned earlier, to see if they work. But it’s really ideal to just replace them with new ones; Porsche stores sell OEM for about $25, the Internet and local parts stores have generics for $7-8. I would go OEM and be done with it.

You can do that and / or place a jumper wire in the fuel pump relay slot and see if that cures it. With a jumper the pump will continuously run until you physically remove it.

Here is your CE panel chart for reference:

https://www.928gt.com/t-8586fuse.aspx