Porsche Enthusiasts Club Forum

Hi guys, do you know any 928 specialists in the South-East? My shark's a 1982 928s with power issues, had a lot of work done on it since I bought it as a non runner including head gaskets, new injectors, WUR, spark plugs, leads, dizzy cap, green wire. the car starts and idles fine but it lacks power, under load it sounds like it's not running in all cylinders. Done a compression test and all cylinders are fine, also checked the cold and warm control pressures and they are ok. No vacuum leaks either. I give up, need a specialist to have a look at it and guide me in the right direction. Thanks, Dan

Before you spend any money, please email JDSPorsche off this forum. Then join the 928uk mailing list. It could be any number of things, if it ws me I'd start with the MAF. JDSPorsche is the man for that, so please speak to him first. Next I'd look at the fuel pump, or a fuel blockage, when was the filters changed last? Search for a fuel flow test on this forum, I think Peanut described how to do it a few months back? I think he was talking about a 928 as JDSPorsche helped out too? I think?

There are people out there who can help, and garages who will take your money, but there are only 3 specialists on 928's in Great Britian. JDSPorsche helped me over the phone when my 928 was only firing on 4 cylinders, he is a gentleman.

Keep us posted on your progress.

The early cars have a "barn door" air flow meter rather than the hot wire electronic mass air sensor which John Speake specialises in rebuilding (this is to under-estimate what he does - he is the foremost expert on the whole LH Jetronic system installed on S2 cars onwards).

No electronics in the air flow meter really, but it's important the doors swing freely and they operate a potentiometer which has to move correctly. I know very little about this component but I expect there are refurb instructions somewhere, but I can't remember it coming up as a problem in all the 928 posts/threads I've read. Always a first time and John is bound to know how to fettle these too.

In your list of works you don't mention the fuel pressure regulator or fuel dampeners. They are vacuum operated, and prone to leaks over time in rubber diaphragms which would cause fuel presure problems and associated running problems.

Pull off the vac lines to each and see if you can smell/touch fuel at end of vac line. That would be sign of vacuum leaking in the relevant part.

Thanks guys, forgot to mention I've installed a new fuel pump and filter as well, done the fuel debit test and its ok, as per manual. Mine hasn't got a MAF as it's the early model with K-Jetronic. Ordered a new coil from main dealer, hopefully this will make a difference but otherwise I run out of things to check and it's becoming very frustrating. I got a long way since I bought the car as a non runner and done everything by myself with info from manuals and forums. But I got to a point where I don't know what to do next, that's why I want to take the shark into a garage and get a diagnostic, trouble is I can't find a 928 specialist around Worthing. On one of the posts someone mentioned Addspeed in Horsham, has anybody used them? Cheers, Dan

Dan you may get bored of hearing advice similar to this, but if you point your car to Stroud and Paul Anderson's garage, it's a cert that he'll find the problem fast and fix it at very reasonable cost.

If you don't want to travel that far then RGA in Vauxhall has an excellent 928 reputation too. That's pretty much it - the 928 simply doesn't have the depth of specialists available for 944/911.

When you say fuel debit test do you mean testing regulator and dampers?

Have you checked timing using the marks on cam gears?

Stratfordshark, thanks for your reply. Paul Anderson is a bit far for me but if I don't have any other option I'll have to consider it. It's just gutting that I've done all this work by myself and I get stuck at the end. Regarding the test, I checked the fuel debit on the return line for 30 seconds as well as fuel presures cold and warm to warm up regulator as per Ben Watson book.
Cheers, Dan

Understand Dan, but people happily travel to Paul Anderson from a lot further than Worthing (eg Scotland) which gives you some idea.

Timing check?

Still worth pulling vac lines of regulator and dampers to check for leaks.

Sounds like you've done loads of work, so I'm sure it won't take long to find problem.

Dan, I agree with the comments above. Dr Anderson will find the fault in half the time and at half the cost of a local garage, and it will justify your travelling costs.

Mid Sussex Porsche Centre in Burgess Hill may well be able to help. Peter Rowe in the service department has long been a fan of the 928 and owned many himself.
Think they offer good hourly rates for club members and are good with advise on the phone.
Worth a try I would think

Just to add to this for anyone's future reference in the south east with a 928 needing work or a service.
I use Leigh's Garage in Earls Court on my S4 (and 944 T's) and was amazed at his knowledge of the 928 (and reasonable rates) tel 0207 386 9947.