doug928

This might be old news but there is a nice article in 911 & Porsche World about John Speake and his MAF & ECU refurbishing. It also states that he will be shortly selling his own version of the Bosch Hammer.

John Speake

Thanks Doug - this is the September issue. (the October issue is now out in the UK)

I will have a first batch of diagnostic testers ready by the end of October.

doug928

Just post it when there ready - i would like to get my hands on one.

Thanks.

Tony

What are these for??

Jim R.

Tony,
I believe the tester will check the on board diagnostics for fault codes. A bosch hammer will do this on 1989 and later cars, and makes troubleshooting sensors, etc. easy. I had my codes read after picking up my GT due to a pinging issue under full throttle, and both knock sensors had fault codes. It made for an easy diagnosis instead of hours of troubleshooting. BTW, do you ever hear from Ben U. in Georgia.?

John Speake

Hi Tony,
Jim R. has it correct, the tester will read out LH, EZK, PDS and airbag ECU fault codes, reset fault codes. reset the idle speed, also do the knock counting function.

It also will actuate the various valves etc, for fault finding. So you can (for example) pulse the idle stabilisier valve from one end of its travel to the other, and check that is is working OK. Same for the "flappy", fuel tank vent valve, idle throttle switch, WOT switch, park/drive switch etc.

John

sharkmeister85

Is it safe to assume this tester will have no applicability for earlier ('85-'86 US) LH models?
Glenn

John Speake

Hi Glenn,
You are correct. Diagnostics started officially with MY 88 cars. The '87 S4s were wired for diagnostics, all they need is the EPROMS on the LH and EZK changing and then they have diagnostics.

87 and 88 have the 12 pin diagnostic connector near the ECUs. The 89 and later have the 19way circular one, under the "hump" at the side of the passenger seat.

sharkmeister85

Thanks, John.
It seems most of the discussion on brain failures relates to the later LH version ('87 up). What kind of symptoms would one expect to see from a failing early version ('85-'86), if any, other than a simple "no-start" scenario?
Glenn

Thaddeus

I, too, would be interested in digging into my 86's brain...

John Speake

I've never looked seriously at the LH2.2 ECUs as fitted to the US85/86 cars (and also the Euro S2 '84-'86).
This is because they are very rugged, and I am very rarely asked if I can repair them.

The LH2.3 series, used on the S4 onwards, has a design problem in the hybrid "tile" circuit. They are especially prone to static/surge damage, but also seem to fail over time. Anything over about 12 years, and you're on borrowed time !

The only recurrent problem with the LH2.2 controllers that I've heard of is the speed pulse interface between the EZK on LH. Other than that, most damge os due to abuse, caused by bad work on the car.

sharkmeister85

[QUOTE=John Speake]
The only recurrent problem with the LH2.2 controllers that I've heard of is the speed pulse interface between the EZK on LH. ....../QUOTE]
What kind of problem is that, John? How does it manifest itself (symptoms)? I've never heard of the "speed pulse interface" (amongst alot of other things )
Glenn

John Speake

Hi Glenn,
Basically, it's a no start. The fuel pump doesn't run because of the lack of this signal.

This speed pulse is the signal from the EZK to the LH which tells the LH to energise the fuel pump. The speed pulse also times the injectors to fire at the correct time.

The EZK genrates the signal from the signal it gets from the flyheel sensor (on top of the bellhousing)