Keithr726

Yesterday I drove my 83 for about a half hour and then it started idling low (500RPM). I just revved it a little and turned around to go home and notice that the temperature gauge was reading maximum. I stopped at a friends house on the way home hoping that it would cool down while I was chatting. I talk for about ten minutes and go to start the car and I hear a "zzzzzzz" and it doesn't attempt to turn over. I pop the clutch to start it and drive home. I pull into the garage and it is still idling low and temperature still reads max. I turn it off to see if I can start it up again and nope, just the fan comes on and the "zzzzzzzz(fuel pump maybe?)" I let the car sit for about 45 minutes and it starts right up. Then it begins to surge/pulse from 500 to 1300 RPM over and over again without slowing down or stopping. The garage also smells of gas really bad.

Today the car starts right up no problem and idles fine. The temperature bar rises quickly. It reaches the 1/2 mark in about 4 minutes and begins to do the surging idle thing again. The bar reaches max in 4 more minutes. The exhaust smells like gas. I put it back in the garage and go right to the computer.

Here is a video showing the idle pulsing:
http://s22.photobucket.com/albums/b3...0610061407.flv

I'VE BEEN TRYING TO SELL THE CAR AND NOW THIS
PLEASE HELP!! I'M DESPERATE

Keithr726

I'm guessing fuel regulator.

Keithr726

No ideas?

mel_t_vin

how often have you been driving the car? did these things [low idle, indicated high temp, no hot start] all happen at once?

first of all, you need to determine if the car is actually running hot or just indicating hot. driving the car when it is actually overheating [in the red zone] will lead to very costly repairs. if you can get your hands on a laser thermometer, take some readings of the head, the radiator, and the upper and lower radiator hoses, and post the figures here for folks to look at.

a high temp indication can be caused by a number of things [faulty temp sensor, faulty grounds, faulty gauge]. that would be best for you, meaning the car is not actually running hot. a hot running condition can also be caused by a number of things [faulty thermostat, faulty radiator, faulty water pump, air in the system]. this would most likely require replacement of parts.

a hunting idle is often times caused by a faulty idle control valve, a vacuum leak, a faulty air flow meter, or a faulty throttle position switch. both the factory workshop manual and the haynes manual have operating specifications for each of these sensors [acceptable voltage/ohm readings]. a little bit of elbow grease and an investment in a good multimeter will pay dividends here.

your hot start problem could be caused by a faulty fuel pump, a faulty fuel pump check valve, leaking injectors, a faulty fuel pressure regulator, and maybe a faulty fuel pressure damper. most folks here would probably recommend that you take pressure reading off of the fuel rail during various operating conditions [off, starting, idling, throttling] to get a better picture of you fuel system. many problems are caused by the simplest failure...and since you said you are experiencing excessive gas vapors in the garage and a heavy fuel odor in the exhaust [running rich], i would venture to say you have a faulty FPR.

keep us posted...

Keithr726

Ok, I read over some old posts and started cleaning grounds. I go to take off the reference and speed sensor connection holder and one of the lower plastic connector breaks into a bunch of pieces. The one above is now cracked too. Which one is which? Well i can get the reference sensor at autoatlanta.


I've heard that the reference/speed sensors can be a fix to my problem also...Is that right?

Keithr726

Do I need a speed impulse sensor (g94460621000) or a rear speed sensor(g94460640102)?

Keithr726

mel_t_vin, I drive the car a few times a week, mostly on weekends. I've only driving it about 2,000 for the year and a half I've had it. Everything started at once. I'm thinking the idle and the temp are cause by two seperate bad parts.

The hood is warm but not hot to the touch while the engine is hot to touch. No smoke, nothing is melting.

Bad reference and speed sensors can do this too right?

Keithr726

Now the car won't even start....great, puts me in a wonderful mood.

mel_t_vin

first of all, you should probably spend a little more quality [driving] time with your 944. she would really appreciate it. second, yes, your hunting idle and [indicated] high water temp are probably two separate problems. third, putting your hand on the intake manifold or cam tower to determine engine operating temperature is probably not accurate enough. and fourth, yes, a faulty speed or reference sensor WILL prevent your car from starting.

the speed impulse sensor you referenced [944 606 210 00] is actually the speedometer sender that resides in the transmission. replacing this part WILL NOT help your no start problem. and regarding the other part you referenced, the rear speed sensor [944 606 401 02], at this point, i'm not sure what that part actually is. the speed and reference sensors which attach to the top of the bellhousing are the SAME part [944 606 115 00].

while you are there, i would recommend that you replace both of your sensors, as the second one is probably not far behind the first one [in disintegrating]. the procedure for removing, gapping, and reinstalling the sensors is described in the factory workshop manuals, on www.clarks-garage.com, and probably somewhere here on the rennlist water-cooled forum. the procedure is not too difficult but it is important that the sensors are properly gapped to the flywheel [0.8mm if i recall correctly]. if you have questions reinstalling the speed/ref sensors, start another thread here. there are many knowledgeable people on this forum. once you replace the two sensors and get the car running again, we can start tackling your other issues [hunting idle, high water temp, no hot start].

keep at it and good luck...