Dave944s87

1987 Porsche 944S

Issue:
It smells like it is running rich.
Strong odor from tail pipe.
Doesn’t run as smooth as would be expected when slowly increasing throttle.
Light vibration at low to medium RPM.

History:
NEW parts installed:
Sparkplugs
OEM Bosch Fuel regulator
O2 Sensor
Injectors
Engine DME Temperature Sensor (NOT Coolant Temp sensor)
Timing Belt
Rotor Cap
Remanufactured DME
Exhaust cat back OEM stainless

Tested:
AFM
AFM Air Temperature Sensor
New O2 sensor for operation

Gentlemen I’m lost. I have spent hundreds of dollars and countless hours trying to fix the smell. Tonight I tested the O2 sensor and installed a new Fuel regulator with no luck. I have ran through every Forum I could find and still no luck.

My next move. What do you guys think?
I installed a new timing belt as soon as I got the car because I didn’t know the history. I sent the timed it using the factory timing marks, but I noticed a paint mark, as if someone marked it, on the cam shaft sprocket. I really don’t want to rip into it again but do you think that the valve timing is off? Should I have used the paint mark for timing instead of the factory timing mark?

Dave944s87

Any thing I missed?
I've hit a mechanic block

Dave944s87

Additional symptoms: so I drove the car around today and went into a couple of stores. When I came back out and start the car it started fine but when I went to leave the car would hesitate badly and sound if it would almost die. If I gave it throttle it would almost die. I had to feather it until it got up in rpm. It then smoothed out and ran fine (by fine I mean slightly rough and smelly). It did this every time I stopped today.

mel_t_vin

Dave, as a brand new "user", it couldn't hurt to introduce yourself, provide a snippet of how you came across your car, and post a few pics.

Regardless, back to your issue...

Have you examined every vacuum hose and control line for splits/cracks? Pull the control line off the FPD [fuel pressure damper] and look/smell for fuel.

What is an "engine DME temp sensor [not coolant temp sensor]"...the sender on the block between cyl 1/cyl 2 for the in-dash coolant temp gauge? If so, that sender does not provide any input to the DME...you need to replace the DME coolant temp sensor on the block coming off the water neck.

How was the AFM tested? Tested throughout the full range of the "barn door"? Matters not...could still be your problem. Also, test/swap/replace your TPS [throttle position switch].

Lastly, your hesitation/stutter at idle is most likely a gummed up ICV [idle control valve]. It resides under your IM [intake manifold] between runners 2 and 3.

Dave944s87

@mel_t_vin
Where should I post my intro as a new user? And that I am new. I haven’t used forums much.
Ill check the FPD tomorrow. I was told that a vacuum leak would make it run lean, it that correct?
There is two identical coolant temperature sensor from what I have gathered. One for the gauge and one for the DME. I replaced the one toward the front of the car which I believe is the DME sensor from the pictures I’ve seen.
I do have a New TPS I haven’t put it on yet.
I haven’t heard of the ICV. I check it out.
Thank you for the feedback and advice

mel_t_vin

Dave, post your intro right here.

"Hi, my name is Dave and I've had my '87 944S for XX years. Here are a couple photos. Strange thing happened on my way to Starbucks, XX years ago..."

The two coolant temp sensors are not identical...the one toward the front of the car, coming off the water neck on the block, is the DME temp sensor. It has a blue connector head. The one residing on the block between cyl 1/cyl 2 is the in-dash gauge sender. If you changed the [blue head] sensor on the water neck, you are good to go.

When you install your TPS, make sure it's done correctly so the idle contact circuit opens/closes properly [with an audible click]. Spend some time on: clarks-garage(dot)com.

I also noticed you installed new plugs, cap, and rotor...what about ignition wires?

If you search the forum, you'll find the AFM has an internal spring-loaded arm that sweeps across a contact area to provide a variable output voltage. Over time, the arm wears a "rut" in the contact area. Solution: bend the arm, carefully, to sweep a slightly different path.

jr10cross

I had the same issue on my 84 that I recently purchased. mel_t_vin is right on the money. I first clean my throttle body, adjusted my idle/fuel screw, but I couldn't stand in the garage with the door open while the engine was running. The fumes were that bad. My vacuum lines were incorrectly connected. Here's a video of how to connect the lines correctly.


Check out my channel, it has other repair videos that might be helpful as well.

Thanks!