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Posted by: 914_teener Sep 5 2010, 07:17 PM

Ok...the skinny. Still have the 1.7 d-jet and today had my first mysterious problem.


Driving and cruising at about 3400 RPM's and it cuts out briefly a couple of times so I kick back on the gas and hit the exit. Got off the freeway and the idle would cruise up to 1400 RPM's and then cut out and die. Pulled up underneath the bridge....where I figured I would be out of the sun. Waited ...started up and idled rock steady at 800 RPM. Got on the freeway again ....just kind of cruised back home never above 3100 RPM.

Put it aside for a couple of days.....drove it this morning...did the same thing at a stop light....idle went up to 1400 RPM and then died. Started up....went home.

Any clues.....?

Thought about the MPS starting to go bad or a stuck advance plate on the dizzy.

Thanks for anyplace to start....

Rob

Posted by: Als914 Sep 5 2010, 08:18 PM

Your head temperature sensor may be going bad . It's telling your ECU "I don't know how much gas you need? So I'me going to shut you down " Replace it.

Posted by: jim_hoyland Sep 5 2010, 08:41 PM

See: http://www.ratwell.com/technical/TempSensorII.html

Not exactly the same, but it shows the sensor can be tested. Max resistance at ambient temps before starting, lower resistance as the engine warms. I'm sure the exact measurments have been posted

I had to test mine on the 1.8 L Jet seeral years ago. Turned out it was not the probleem and I saved some time and $$.

Good Luck

Posted by: Rotary'14 Sep 5 2010, 08:51 PM

You described the classic symptoms of a fuel filter that is starting to plug up,, when was the last time you changed it?

-Robert

Posted by: roadster fan Sep 6 2010, 01:26 AM

I was gonna say the same thing, fuel filter. that is what I would check first. The tank could have some crud blocking the outlet too, so if the filter is good to go, make sure gas is getting to it.

After that it is time to test the FI components. Check out Brad Anders djet site on rennlist. it is all you will need.

Jim

Posted by: swl Sep 6 2010, 05:46 AM

Our ecu is not that smart. Bad cht simply makes it run too rich.

Fuel filter sounds reasonable to me. Another possibility is the relay board fuse. They can get heat sensitive when the connection goes bad. That wouldn't cause the surge though.

Posted by: 914_teener Sep 6 2010, 09:09 PM

Ok....thanks all. Think I'll test the CHT sensor and then check the fuel filter.

Think also will test the MPS for bleed down as well.

Thanks...I'll post results.

Hope everyone had a happy holiday.

Rob