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Posted by: srb7f Sep 4 2009, 10:22 PM

I just want to give a shout out to Dave Sprinkle who is now making brand new TPS circuit boards for the 914 FI system.

This is seriously the best $35 I've spent on the 914 in as long as I can remember. It's a simple installation with the included instructions, and only took me about 30 minutes. After this, all of the jerkiness in the acceleration was gone just like that.

A new TPS is NLA, and cost about $150+ last I checked when they were available. This $30 part restores the switch, so get one while you can.

This will certainly keep me happy with my 2.0 until I have the time and $$ to convert to a 6!

Posted by: Dr Evil Sep 5 2009, 12:59 AM

Badass! Way to go Dave

Posted by: saigon71 Sep 5 2009, 06:53 AM

Steve:

This is great news! What is Dave's "handle" on this forum. I would like to order one.

Thanks,
Bob

Posted by: jimkelly Sep 5 2009, 07:14 AM

now THAT is truly stepping up to the plate - wow

http://www.914world.com/bbs2/index.php?showuser=2943

Posted by: saigon71 Sep 5 2009, 07:18 AM

Thanks Jim. Just sent email.

Posted by: zymurgist Sep 5 2009, 09:27 AM

I got mine yesterday. Thanks Dave!

Now it's on my "to do" list for this long weekend.

Posted by: srb7f Sep 5 2009, 10:42 AM

Amazing, no doubt. I can do just about anything in terms or wrenching on these cars, but generating one of these circuit boards is definitely out of the prowess of an amateur mechanic like myself.

Posted by: gothspeed Sep 6 2009, 11:22 AM

I need one of these ....... this will work on the 1.7 D-Jet also right ...... ??

Posted by: jsayre914 Sep 6 2009, 11:41 AM

pm sent

Posted by: PH1 Sep 6 2009, 11:51 AM

I received my TPS circuit board and plan to install it today. The instructions do not say to remove the TPS. Step one says to remove the cover and step 2 is to drill out the rivet. I'm not sure it is possible to drill out the rivet while the TPS is installed.

My questions are:

1.) Do you completely remove the TPS ?

2.) Do you have to recalibrate the TPS after this procedure?

Posted by: davesprinkle Sep 6 2009, 09:39 PM

Kelvin has correctly identified a weakness in the instruction sheet. (Thanks, Kelvin.) Yes, the first step should be: remove the TPS from the throttle body.

Obviously, reinstallation will require that you follow the TPS calibration procedure. (My understanding is that it can be found on the Pelican site.)

Thanks again for pointing this out, Kelvin. I'll update the installation sheets.

-dave

Posted by: davesprinkle Sep 6 2009, 09:41 PM

Sorry, the 2.0 liter and 1.7 liter sensors are different. I am currently setting up to make the late 1.7 liter boards. Should be a month or so.

How can you tell if you've got an early or late board? The early boards had wires soldered to the board. The late boards have spring-loaded contacts.

Posted by: srb7f Sep 6 2009, 09:52 PM

Well, I thought they were great instructions, but I didn't even open them until I got the TPS out on the workbench.

Posted by: blitZ Sep 7 2009, 07:26 AM

I've been trying to sort out some poor idle and hesitation and think it may be my TPS. Is there anyway to determine if it is bad? Visually, it looks fine and I have calibrated it.

Posted by: davesprinkle Sep 7 2009, 09:07 AM

The TPS has two functions:
1. Idle indication. The TPS has two contacts that indicate when the throttle is fully closed. The TPS calibration procedure takes care of this function. Your car will idle poorly if the ECU doesn't know that the throttle is closed.
2. Transient throttle detection. The serrated traces on the board act to detect changes in throttle position so that the ECU can add additional fuel. The car will have poor throttle response if this circuit isn't working properly.

If you've performed the TPS calibration procedure and you still have poor idle, you should verify that your sensor wiring is OK. Check the continuity of the leads from the TPS connector to the ECU connector.

Posted by: jim_hoyland Sep 7 2009, 09:57 AM

Nice update and follow through Dave. Tell me: how is the 1.8 L-Jet TPS different ?

Posted by: zonedoubt Sep 7 2009, 12:30 PM

It's not a wiper style, just a two-position contact switch.



http://manuals.type4.org/ljet/tests/ljet13.htm

Posted by: jsayre914 Sep 7 2009, 01:11 PM

the paypal address you gave me is not working. can you please send me the correct address.

joe

Posted by: zymurgist Sep 7 2009, 03:05 PM

I installed the circuit board in Babydoll today and WOW, what a difference! No more bucking! This is the most awesome (and necessary) part I've seen in a long time. Thanks Dave!

In other news, I'm so happy it came with 2 rivets. I promptly lost one in my kitchen and it still hasn't turned up.

Posted by: roadster fan Sep 7 2009, 03:06 PM

OT but I have to ask. Are you the Dave Sprinkle I saw the other night on TV that is involved with Motoczysz?

I thought I recognized the name when watching "Birth of a racer" but couldn't remember from where. If it is you, what an amazing company!

Jim

Posted by: Todd Enlund Sep 7 2009, 03:50 PM

Yep, that's him. Dave is a very humble guy... I rode to Everett and back with him one Teener Tuesday last Autumn to Mr Bovey's house, and he never mentioned MotoCzysz or TRD. All that I knew at the time was that he was an unemployed engineer...

Posted by: SirAndy Sep 7 2009, 04:07 PM

Posted by: davesprinkle Sep 7 2009, 05:59 PM

I'm gratified to hear your repair was successful. Thanks for following up.

I'm glad you were able to use the spare rivet. That 3/32" rivet can be troublesome to source -- most hardware stores only carry 1/8".

Posted by: zymurgist Sep 7 2009, 06:07 PM

It doesn't show up very clearly in these pictures, but the center circuit actually has a little divot worn into the board right at the point between the traces.

Posted by: Gint Sep 26 2009, 09:10 AM

How does a guy go about buying one of these Dave? PM on it's way. Do you have a thread in the member vendor forum here?

Posted by: davesprinkle Sep 26 2009, 09:25 AM

You can PM me and I'll send you my Paypal address. I don't think I'm in the vendor section yet. Guess I should do that...

By the way, the thread title is a bit misleading. These are $35/each, not $30.

Posted by: Gint Sep 26 2009, 09:53 AM

Fixed the thread title. Thanks Dave!

Posted by: thewheel69 Oct 12 2020, 10:05 PM

Hey @http://www.914world.com/bbs2/index.php?showuser=2943 , we meet again! (Talhina ride and some Dallas events) anywho...
Ive read through this thread and also done a fair amount of researching any mention of a 1.8 DJet TPS board???

Did you happen to make these by chance and if so what is the best means to contact and procure?

Thanks for your amazing dedication!

John Foster

1974 Ravenna Green 1.8 (Wazabi)

Posted by: davesprinkle Oct 13 2020, 11:47 AM

John, thanks for the kind words. Sorry, I never made any of the Ljet boards. Not sure how you would go about getting that fixed. Probably just need to get a replacement sensor.

With regard to the Djet boards, I have a handful left, but I'm not going to make any more. I believe that 914rubber is now making these. I'm glad to have supported the community with these, but there's just not a big enough market to support two vendors.

Thanks again. Good luck.