JoeNational

First. I'm new here and wanted to say hello and glad to be here.

Car:
1986 944 turbo with Vitesse MAF kit.

I bought this car in spring of 2012 and everything was fine until last year.

Issue:
Once car warms up she will not go past about 1600 RPM. I have replaced DME temp sensor and TPS (made sure it was set per Clarks-garage) with no resolution to the problem. Once again it starts and can hold an idle and will be even respond with no issues when cold. Once it is warm it just continues to bog. I just had to replace the battery and then when I went to start her up she was fine. let her idle for a while and was giving it gas wiith no issues. I backed it up the drive way and started driving and no problem. Shifted into second and then there it was again. Bogging so bad. I limped it around the block back to the house. Held the idle and never died just completely bogged the car as if I didn't know how to drive stick or hitting rev limiter.

I have been doing reading and see that there is an internal Air Temp sensor for the Vitesse MAF kit. Could this be the culprit? Why after it warms up? I will also add that after starting her countless times today it gets harder and harder for her to actually start and stay running.

No other mods done to the car. I have checked everything you would normaly check. Air leaks, connections, etc... I do not see any thing sticking out.

Please help... I want to driver her so badly and she has been sitting long enough.

V2Rocket

Do you have a wideband O2?

944Phil

I don't have a Vitesse kit in my car but I've seen some threads pass where you need to make sure the grounds are clean or the vitesse can have issues.

JoeNational

Sorry I do not have a wideband 02 at least I dont think so. How does one check.

I'm checking all connections as well.

Van

Since the MAF kit is connected to the factory harness, I'd check those connections first. Sounds like the computer is only "seeing" the idle amount of air going into the engine, so it always sticks with the idle amount of fuel.

That idle amount might be the baseline or the default setting.... so start with those wire connections.

mikeyoman

Did you check the TPS idle switch on pins 4 & 6 with a meter to make sure the switch is opening ?
Although you will be able to hear the switch click when the throttle is opened slightly, if it is not opening properly the engine will go into coast/surge mode at 1600 rpm. or there might be a short circuit on pins 4 & 6 going to the DME ?
Try running the engine without the TPS connected see if your 1600rpm cutoff is still happening.

black944 turbo

Check the maf itself and the power wire going to service port. When I had my maf kit the power wire came loose and the car behaved very much like you are describing. I would venture to say that it something in the maf area. Contact John at vitesse and see if he can help with some diagram steps.

JoeNational

What reading should I get on the 4 and 6 pin's? is this on the TPS itself or on the DME? I do hear the audible click as soon as I start to move it so I know it is set right.

When you say the power wire going to the service port are you talking about this (see attached) you could see as I was chasing the wires they didn't even use the bullet style connector. Does it matter which port I plug it into?

I was speaking with John via email and he mentioned getting a motronic monitor which does look to be a good investment but I need to see if I have the circuit board first before I purchase that. Does anyone have a wiring diagram of the MAF kit available. I cannot find one.

Thanks again!

black944 turbo

It does matter which one. As for the connector it is the correct one for the port. If that is disconnected, then you found your problem. One of the ports sees voltage and the others do not. You can play with it by testing the pins with a multimeter. I believe you should see power with the ignition on.

Cyril

Joe, you have a PM

JoeNational

I do want to make sure I'm clear that this was connected, I just disconnected in this pic because I saw they just shoved this into the port without an actual connector.

I will test each port with ign on!

black944 turbo

That is the correct way it goes, it should go in the connector and fit snugly. The plug for the test port is supposed to have a cap on it and this is the reason why the connector is small, so that the top cap can close. Yours is not supposed to be loose like that and is supposed to have a cap on top that clips on.

JoeNational

Yea this did not have a cap. It was covered with electrical tape.

black944 turbo

Ok, it also supposed to be securely mounted to the bracket pictured in the lower rt. side of the photo. Check voltage at the port and then at the connector for the maf. Make sure the wire is not broken inside.

Tsmith84

I have the install instructions in PDF that John sent me a while back. He was very helpful with my situation. Let me know your email if you'd like me to forward them on.