MPS Options

[Bullet]

I can seem to get my 914 to not run Rich. I have checked Injector spray paterns, replaced cap,rotor, points, condensor,plugs, plug wires. and belive that my vacuum routing is correct. I question the integrety of the MPS. if i remove the vacuum hose that runs to it and clamp it off i get no change at all in performance. I was told by a co-worker that i should drill out the riviots and check to see if it is gummed up. I just removed it and am getting ready to take it apart, when out of curiousity I ohm checked the teminals and this is what i got : pin 8 - pin 10 350 ohms, pin 7 - pin 15 90 ohms. is this normal? does anyone know of any way to check the MPS. Or could any one do a quick ohm check on theese terminals to let me know if that is a correct reading? any help would be greatly apreciated.

[gklinger]

Pretty much everything you could want or need to know is at:

http://members.rennlist.com/pbanders/manif...sure_sensor.htm

[Bullet]

Thanks for the link. I was just surfing around on pelicanparts.com when i ran in to this: Fuel Injection Trigger Points

These are the trigger points that are located inside your ignition distributor. Often overlooked by owners when diagnosing your system, these points send the pulse to fire the fuel injectors. Replace your fuel injection points if you find that your injectors are not firing correctly.

WHOA!!!! what the hell is this, were is this, does my car have this?

[gklinger]

WHOA!!!! what the hell is this, were is this,  does my car have this?

If you have a intact D-Jet system you do. They're in the base of the distributor. Before you get too set on one course of action, check out Brad Anders' site, he's got all the diagnostic info you could need.

[Bullet]

I read through his site and still come to the conclusion that it has to be my MPS. I have a verry rich run from idle to WOT. I have to drive it from my work to my house last night. only 3 miles but more then i wanted to with it running that bad on a new rebuild. the hole time of driving it it blew Black smoke out in huge clouds. according to that link you posded for me the OHM specs are good. and I am going to vacuum test it here in a bit once i find a pump to use. Mine is at work and they are closed today (IMG:style_emoticons/default/sad.gif) . if i fail the vacuum test were is the best place to find a rebuilt, for a reasonable price. I can do a dual webber kit for $800. so if i cant find a MPS for less then that I will be going with the webbers.

[mike_the_man]

First of all, pull a vacuum on the MPS. I bet that the diaphragm is cracked and it won't hold a vacuum. If it does hold a vacuum, test the resistance of the coils. The values that they should read are listed on Brad Ander's website.

Read over everything on Brad's website before you start messing around with stuff. You could also lean out the mixture using the knob on the FI Brain.

[Bullet]

Well it looks like i wil have to wait untill tomorrow to vacuum test the MPS. I cant find one that some one will let me barrow for a minute, and the auto parts stores wont let me open the package real quick.
Now for the FI trigger points is there a way to gap them or how does this work exactly?

[mike_the_man]

Not much you can test with the trigger points, as far as I know. I'm pretty sure they don't need to be gapped. The only way I figured out how to test them was by testing for continuity between the outer and middle terminals on the connection. During half the rotation of the rotor, one side should be making contact, during the other half of the rotation the other side should make contact. Does this make sense? (IMG:style_emoticons/default/wacko.gif) There should be more info on Brad's web page.

[pbanders]

Rich running can have several causes. First thing to check is the MPS vacuum integrity. If it won't hold a vacuum, it's no good and you'll need a rebuilt (~$250) or new OEM unit (~$1000). Other major causes of rich running are:

* High fuel pressure
* Defective cylinder head temperature sensor

Brad Anders

[pbanders]

If your car has over 100K miles and you don't know if the FI trigger contact points have ever been changed, then change them.

[Bullet]

If your car has over 100K miles and you don't know if the FI trigger contact points have ever been changed, then change them.

102k to be exact. yeah I will probally order them up tomorrow. the fuel pressure is at 2.0bar. and for a while there i thought that it was injector spray pattern but i have tested that and they all have nice cone patterns. head temp sensor is new. then cold start vale is not stuck open. and i checked with a noid light for signal from ECM and they dont apear to be squirting more then they should be (steady pulsing of the light)

Rich running can have several causes. First thing to check is the MPS vacuum integrity. If it won't hold a vacuum, it's no good and you'll need a rebuilt (~$250) or new OEM unit (~$1000).

Where can I buy a rebuild one?

[pbanders]

Where can I buy a rebuild one?

Performance Products (www.performanceproducts.com) has them. They're not in the online catalog, call them, it's something like $250 w/exchange of your sensor.

[Bullet]

Performance Products (www.performanceproducts.com) has them. They're not in the online catalog, call them, it's something like $250 w/exchange of your sensor.

I went to that webpage to just look at what they had to offer and i came across this
Webpage And i just found this thing sitting in the glove box today. I didnt think it was for the 914. Now i would like to know what it is, and were it goes.

[tod914]

Goes right behind the Heat level inbetween the 2 seats. Maybe an inch or so foward of the center seat cushion. There is a back plate with a bulb and wire. You should find the wire under your center carpet piece.

[lmcchesney]

Brad has given you the method of checking the vacuum seal and resistance on your MPS. IF you want to buy a different/rebuilt one, I saw this one on evilbay.
http://cgi.ebay.com/ebaymotors/ws/eBayISAP...&category=34198
L. McC

[bob174]

I saw some advice about adjusting the mixture with the knob on the ECU. This is only the IDLE MIXTURE. Check out your MPS per Brad's suggestions. I recently went through this too, and had a bad one in my car--would not hold vacuum. If you find your MPS to be hosed up, contact Bleyseng on this board. He might be able to help you out with yours.

Bob

[Bullet]

Goes right behind the Heat level inbetween the 2 seats. Maybe an inch or so foward of the center seat cushion. There is a back plate with a bulb and wire. You should find the wire under your center carpet piece.

I was putting the center console backin to day and i saw 1 brown wire with a (eye type) conector on the end. in the area you are talking about but i never saw a bulb or another wire that wasnt hooked up to something. What exactly does it do. just indicate wether the defrost is on?

[tod914]

That's it. That defrost cover has a baseplate which contains the bulb.

[Bullet]

Brad has given you the method of checking the vacuum seal and resistance on your MPS. IF you want to buy a different/rebuilt one, I saw this one on evilbay.
http://cgi.ebay.com/ebaymotors/ws/eBayISAP...&category=34198
L. McC

I did a vacummtest on the MPS today and it failed. So i am going to take my chances with "evilbay" Hope to god it is in working order. I e-mailed him asking if he could preform the resistance checks and vaccum test it for me. I dont like taking chances with stuff like this, But i would be pissed to find out it is a good unit and have bought another one for a higher cost.

[4WheelDrifter]

Bullet, make sure it's the right MPS for your engine and FI's CPU. My 2.0 is running rich too and I'll be doing a test on my MPS soon too. If I find my MPS bad and you are bidding on the MPS posted by L McC, I won't bid.