the flyin' scotsman

Just rxd a refurbed MAF from John Speake and installed it tonight.........the car was idling so fast on start up I had to back off the throttle cable twice to get the idle where it should be.

Then I went for a ride............instant throttle response, smooth power and comes back to idle as it should; great improvement and that from a MAF that when I sent the original to John was not that bad!

If your experiencing a rich tailpipe, so-so off line power and only a OK punch when flooring the pedal you may want to consider the age of your MAF. As has been posted many times, get the car back to how it was when leaving the factory and then if required go looking for more power.

Have a couple of other 'chips' to add and will report form there.

Thx John........excellent product................Malcolm

bwebb77

Hey Malcolm what was the cost? I was thinking of doing it also. PM if you want.

the flyin' scotsman

bwebb77..............I bought a refurbed MAF and GT chips for the ignition and injection brains all at the same time. Contact John though his web site; JDSPORSCHE.COM for a quote to your needs.

He responds very quickly.............Malcolm

bwebb77

Thanks

jyoon

i think i'm gonna go ahead and get a rebuilt mass air also. hopefully it will solve some of my stuttering problems. price was $350 + 100 core when i e-mailed jds porsche fyi.

Garth S

Another happy camper!
I'm pleased with the GT EZK in my S4, but haven't bothered installing the GT LH module ... yet ( with its slightly higher idle). So pleased that you are to be the test mule for this step!

Thaddeus

I replaced my MAF 2 weeks ago with a new unit and am very pleased. Smoother idle, starts up in half a turn (seems like), idles at the same RPM hot or cold, starts fine hot or cold (was balky when warm before). More responsive to the pedal and the power come-on is smoother. The exhaust used to smell of gasoline but no more.

Just like magic! I think the engine is running as well as I'm ever going to get it. Which is to say, running great.

the flyin' scotsman

Thank you Garth

step 2; replacement of the stock EZK S4 eprom with a GT mapped active device. For those who have not done this before and/or have little electonic background you may want to engage the assistance of a friend who does.

DISCONNECT THE BATTERY
The brains are located below the passenger shelf and are best accessed by removing all the carpets and the shelf itself. Both brains are mounted side by side in a frame that is in turn is attached to the passenger footwell by 2 5mm hex bolts. To access these bolts you have to remove the substantial wiring harnesses to each of the brains and gently move them out the way. Once the bolts are removed disconnect the other electrical components and take the framework with both brains to your grounded work bench.

The EZK (ignition) brain is attached to the framework with 4 8mm nuts. The EZK brain is then further disassembled by removing the 8 screws (4 at each end). You can now remove the 2 circuit boards from the covers and open them up leaving the ribbon cable connecting the 2 in place. The eprom is easilly identified as the only socket mounted prom close to the main CPU. Carefully remove the original, there's a small cover over the eprom, and replace with the new eprom, be carefull with the orientation of the 'chip in the socket'. Replacement is the reverse. Keep yourself grounded while doing this operation to prevent ESD.

After all is put back together reconnect the battery and fire her up. My car started with half a turn of the engine setteled to a strong ~700 rpm idle responding very quickly to throtlle input. Out on the highway the car has better low down power and when it hits the 4k rpm it takes off like never before doing well over 200kph before shifting to 4th (auto box).

Not a huge time consumming job especially if your familiar with removing the centre counsel etc.

Observe the electrical cautions and enjoy the re-mapped power band; well worth it. Many thx once again to John Speake.

I'll do the LH soon and post the results...............Malcolm

928Quest

Where are you getting the GT ROM's? If somewone would post a binary image of the ROM (read by a ROM burner) there are probably a few of us who could burn our own copies.

H2

Rather than just change the MAF...would it make sense to make sure that the air/fuel mixture ratio is correct first before going to this expense?

James-man

Does anyone have a favorite thread or tips link for checking MAF?

I have a multimeter lying around somewhere....

James-man

New MAF = New Car, so dash cracks will disappear too?

Just kidding, of course.

I really like the sound of what you have described. Glad to see that your money was well spent on this.

the flyin' scotsman

Chuck..............I got both GT mapped eproms for the injection and ignition brains from John Speake of Cambridge, England. If your not familiar with John's work check out his web site; JDSPORSCHE.COM

I also believe his products are available in the USA from 928 Specialists.

the flyin' scotsman

My car was running rich before the MAF swap. I posted on the topic sometime ago and followed the given advice but no change. The car smelled rich, the tailpipe was sooty and off the line acceleration was not crisp. Given that my car sits in the garage 4-5mths of the year due to our Canadian winter it was an easy decision to remove the MAF and send it to John Speake for analysis. His findngs were that indeed my original MAF was underperforming so having a replacement refurbished MAF was the only way to.

the flyin' scotsman

Thx James.............I believe that Jim Bailey once said that returning the car to original performance status should be the first priority before adding all sorts of other 'goodies'. While I like the thought of 'supercharged' additional performance I want the car to be where it was (or slightly better) when it left the factory. With the new MAF, GT eproms, Nology wires, Disti caps and rotors, Quad 4 plugs, new motor mounts, RMB and regular maintenance items I'm getting there. New Eibach/Bilstien springs and shocks are next to improve the handling; has a 'big boat' wallowing feel over 200!!! also have ordered a X pipe from Tom C that will wait until he's back in production.

Dash cracks will meld together if I go much faster