Manifold Pressure Sensor (MPS) for 2.0L

[3D914]

Where can I find a source for the MPS?

I am need of a NOS or used MPS for a 74 2.0L, Bosch part#: 0 280 100 043.

I am not interested in rebuilt MPS.

TIA,

[Amark]

Here's one ??



http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2404354655&category=34198


Mark


73 2.0

[anthony]

You should be able to buy a new MPS from Pelican. They cost around $600 last time I looked. You can also use an 049 MPS from a 1.7. They are pretty close and more commonly found used. Consult Brad's web site for details:

http://members.rennlist.com/pbanders/DJetParts.htm#Compatibility

[Alfred1]

Right here at Pelican Parts: Pressure Sensor, 914-4 1973-76 2.0L
0-280-100-043 $595.00 . It's always wise to shop around, though. Have you tried your local Porsche dealer?

Alfred

[chrisreale]

The 1.7 is different. Runs leaner, but it does work. Try Rich Bontempi's place High performance house (??), Triad West, Junkyards... I have an extra 1.7 mps, but I think in the lond run you want the 043...

[Bleyseng]

Yes, a 049 MPS will run but it will be too lean at WOT w/ lots of pinging. Keep running it and you will drop valve seats. Post in all the classifieds, here, 914club, rennlist and one will turn up.
Geoff

[Dave at Pelican Parts]

The price in our catalog may be out of date... The 2.0 ones have gotten exceedingly hard to come by any more.

--DD

[3D914]

Dave,

Are the ones in the catalog new, used, rebuilt?

TIA,

[Dave at Pelican Parts]

New. At least they were... I suggest talking to our friendly Sales staff to find out the details, though!

--DD

[pbanders]

Prices continue to rise on these. I bought one from www.thepartsbin.com about 6 months ago for a bit over $500. New price there is $741. If you can find a new one for near $500, get it.

Once these are all gone, then rebuilts will be the only option. We've found that the Bret rebuilds are all adjusted to the same specs, regardless of application (i.e. a 049 is a 043 is a 037, etc.). Additionally, the rebuilts use a different part for the diaphragm that is thicker and does not have the same bellows structure as the OEM part, resulting in a different mixture transition from part to full load.

[3D914]

Thanks guys for the response and the leads. I may end up getting it at PP.

I still need to convince myself that this is the source of the problem - especially before dishing out $600.00. Mine is definately bad, but I have yet to find a spare that is a complete solution (spares only seem to solve part of the problem) - until the engine reaches a mid-range temperature - then the idle drops again.

That's with CO set correctly for the particular test MPS.

Thanks again,

[Bleyseng]

Before you spend $600, does the one you have hold a 15hg vacuum for 5 minutes without bleeding down? If it does hold a proper vacuum and has not been opened up or the epoxy & plug drilled out, it should be fine. What goes wrong with a MPS is the diaphram cracks so the vacuum test will detremine if its good or not. If the MPS has been "adjusted" that could be your problem.
So tell us what problem you are having?
Lots of people decide its the MPS or ECU when that is not the problem at all.
Geoff

[Bruce Allert]

There are quite a few 2.0's runnin' round in the Phoenix area. Try getting together with a few and see if using one of theirs changes your problem. I remember one get together I attended, one of the guys had a problem. We all started puttin this & that on his from ours until the problem was solved. Was fun too!
bruce

[Alfred1]

Originally posted by pbanders
Prices continue to rise on these. I bought one from www.thepartsbin.com about 6 months ago for a bit over $500. New price there is $741. If you can find a new one for near $500, get it.

Once these are all gone, then rebuilts will be the only option. We've found that the Bret rebuilds are all adjusted to the same specs, regardless of application (i.e. a 049 is a 043 is a 037, etc.). Additionally, the rebuilts use a different part for the diaphragm that is thicker and does not have the same bellows structure as the OEM part, resulting in a different mixture transition from part to full load.

Are all of the new 914 MPS's NOS from as late as 1986?

Alfred

[chrisreale]

Hell, ask if you could meet pbanders somewhere. He lives where you live.

[Bleyseng]

Chris, Brad lives waay out in the boonies in Mesa but its a good idea. He should test his MPS first.

[chrisreale]

Originally posted by Bleyseng
Chris, Brad lives waay out in the boonies in Mesa but its a good idea. He should test his MPS first.

oh, his info below his name say Phoenix. At least I got the state right

[3D914]

Geoff,

My MPS passed the test you described, along with the other tests Brad has outlined. The only one I haven't been able to complete is the test for the aneroid cells - which I suspect is the source of the problem.

*********************** The Problem ***********************
Newly rebuilt engine with Euro pistons & #73 Web cam.
Cold starting (above 50deg) is rough and won't maintian idle without applying gas pedal. After a minute or two idle holds fine (with latest test MPS), but only until engine temp reaches mid-way on dummy gauge, then idle drops to around 200rpm or engine dies. It does restart, but requires gas pedal to come around.

A failed aneroid cell in the MPS affects idle and mid-range fuel delivery, causing rich mixture. This fits the symptoms and the plugs that were checked. What's really weird though was that plugs 3 & 4 were soaked and cold, but 1 & 2 were hot and tan colored.

The current test MPS I'm using is an improvement over mine, but it still drops idle down to a few-hundred rpm once mid-range engine temp is reached. Also checked the Cyl Head Temp sensor when hot and it was at 100ohms.

************************************************** *******

I have a source here for other MPS's at Don Jacksons. The one I'm currently trying only resolves part of the problem (as mentioned above). He has another I can try as well. We'll see how that goes this weekend.

Most of the 2.0's I've seen around the Phoenix area (aside from Brad's) run carbs. And I may end up giving him a call, I just want to go as far as I can before getting others involved. I don't mind wasting my own time, but it bothers me if I waste other's.

Thanks again,

[Bleyseng]

So your AAR valve isn't working at start up? You should be getting a idle of about 1200-1500 when first starting due to the extra air from the AAR valve.
Also, check the trigger points in the distributor. Are they new? Sometimes the new ones are defective so check them as you might be getting funny FI pulses because of that. (the lean on one side, rich on the other)
Also, check for a vacuum leaks with starting fluid as you could have one on one side of the motor causing the rich/lean syptom.
I haven't seen a bad aneroid cell yet just the funny steel ones that Brett uses that don't work very well.
Part of the problem is the cam you are using which doesn't have the same strong vacuum signal as the stock cam. (more valve overlap)
Geoff

[hardflex]

I don't think it's the MPS at all, because of the pairings of the richness. Remember, ECU sends signals to pairs of injectors, 2&3, and 1&4. therefore it can't send a signal to 1 which is correct and 4 which is rich, the signal to both would be either rich or correct.

It could be dirty injectors not spraying in a cone shape, or never shutting off completely. Could be wrong injectors on 1&2, or 2&3. Could be an ignition problem like worn distributor shaft bushings, Could be fouled spark plugs on 3&4. But this is good news, all of these things are a lot cheaper than an MPS

I would try this. pull 3&4 spark plug wires at the distributor and lay them in the cap loosely. start the car and warm it up, then pull the wire one at a time away from the cap. This will create a hotter spark which can fire fouled plugs, which you can see and hear. when pulling it away, does that cylinder come back to firing? if so, it's an ignition problem, not a fuel problem. if it doesn't, then pull the injectors and check them.

Hope this helps.