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914World.com _ 914World Garage _ 1.8 CHT sensor
Posted by: djway Jul 12 2016, 04:49 PM
I have a bad head temperature sensor on my 1974 1.8 914. I called Pelican Parts and they say they are not available. My car is just dumping fuel and I cant drive it until I get a new one.
Where can I find them?
Thanks
Dwayne
Posted by: Dave_Darling Jul 12 2016, 04:55 PM
The D-jet ones should work, at least to some extent.
--DD
Posted by: djway Jul 12 2016, 05:04 PM
The D-jet ones should work, at least to some extent.
--DD
According to all the sources I can find the CHT sensor is the same part for all the years. Many VW models used the same part. Cant find it.
Posted by: Big Len Jul 12 2016, 05:26 PM
Does this help?
It's.....gulp, Auto Atlanta http://www.autoatlanta.com/results.php
Posted by: The Cabinetmaker Jul 12 2016, 05:51 PM
http://www.bughaus.com/type_4_fuel_injectors_and_seals.htm
Posted by: djway Jul 12 2016, 05:57 PM
Does this help?
It's.....gulp, Auto Atlanta http://www.autoatlanta.com/results.php
out of stock
Posted by: djway Jul 12 2016, 05:58 PM
http://www.bughaus.com/type_4_fuel_injectors_and_seals.htm
Not available per the page
Posted by: jim_hoyland Jul 12 2016, 06:40 PM
Try a VW shop that's servicing buses....virtually the same motors IIRC
Posted by: 914Sixer Jul 12 2016, 06:42 PM
What is the part #? The bughaus page is showing 0280130012 that is for a D-Jet. It is a common head temp sensor.
Posted by: djway Jul 12 2016, 09:22 PM
What is the part #? The bughaus page is showing 0280130012 that is for a D-Jet. It is a common head temp sensor.
When you click on the part to order the next page says "Not available" The part number is the same, the D and L both use the same CHT sensor.
I have tried all sorts of web sites and once you click to order they are not available.
Posted by: MarkV Jul 12 2016, 11:46 PM
http://www.ebay.com/itm/Porsche-Sensor-Cylinder-Head-Temperature-70-76-914-4-914-6-0280130012-/222115129865?hash=item33b717ea09:g:g3oAAOSwlfxXFkex&vxp=mtr
Posted by: jcd914 Jul 13 2016, 12:45 AM
Not to say that you don't need a CHT sensor but how did you determine you need one?
The CHT is not a common failure point and I dont think I have ever seen one thta failed such that the engine was being flooded with fuel.
I would be more suspicious of the Air Flow Meter than the CHT sensor. They are known for sticking and binding.
Jim
Posted by: djway Jul 13 2016, 12:46 AM
I have a bad head temperature sensor on my 1974 1.8 914. I called Pelican Parts and they say they are not available. My car is just dumping fuel and I cant drive it until I get a new one.
Where can I find them?
Thanks
Dwayne
After hours of searching I finally found a place that provided a new part number.
Engine Cylinder Head Temperature Sensor-Bosch 802 54117 101 Around $30
It list all of the same vehicles as the old part number.
Funny that all the Porsche sellers don't seem to know this.
It made no sense that this many vehicles would have no supply
Posted by: djway Jul 13 2016, 03:22 AM
Not to say that you don't need a CHT sensor but how did you determine you need one?
The CHT is not a common failure point and I dont think I have ever seen one thta failed such that the engine was being flooded with fuel.
I would be more suspicious of the Air Flow Meter than the CHT sensor. They are known for sticking and binding.
Jim
Measured its resistance. I had another one sitting around that gave a better reading and put it in. it runs now. I want to put a brand-new unit in to get even better reading.
Posted by: djway Jul 13 2016, 03:23 AM
http://www.ebay.com/itm/Porsche-Sensor-Cylinder-Head-Temperature-70-76-914-4-914-6-0280130012-/222115129865?hash=item33b717ea09:g:g3oAAOSwlfxXFkex&vxp=mtr
Price is nuts
Posted by: djway Jul 13 2016, 04:51 PM
Well, I ordered under that new part number and guess what, not available.
I finally talked to someone that actually knew about the problem at the Bus Depot. He was baffled about what to do.
Every single type 1,2,3,4 aircooled and some watercooled with fuel injection use that same exact sensor.
Posted by: 914Sixer Jul 13 2016, 08:37 PM
I do not understand what happened to all the sensors, you could buy them all day long for less than $30 bucks. I checked all my sources and they came up empty. 
Posted by: Keith914 Jul 13 2016, 08:56 PM
I have one recently removed from my '72, Yours for the cost if shipping and $5 for my effort to ship.
Posted by: McMark Jul 13 2016, 09:46 PM
$30 I'll send you one of my custom ones that are better than stock.
Posted by: djway Jul 13 2016, 11:31 PM
$30 I'll send you one of my custom ones that are better than stock.
How are the different from stock?
Posted by: RohJay Jul 14 2016, 12:14 AM
http://www.ebay.com/itm/Porsche-Sensor-Cylinder-Head-Temperature-70-76-914-4-914-6-0280130012-/222115129865?hash=item33b717ea09:g:g3oAAOSwlfxXFkex&vxp=mtr
Price is nuts
That is astounding..
I bought the following on ebay for 23.70 last Aug. It had sold last at 74.95 :
http://www.ebay.com/itm/361069640496?item=361069640496&viewitem=&vxp=mtr
If USED is ok, have you checked Samba? Here's a couple I came across:
http://www.thesamba.com/vw/classifieds/detail.php?id=1586361
http://www.thesamba.com/vw/classifieds/detail.php?id=1804271
Posted by: Mikey914 Jul 14 2016, 12:24 AM
$30 I'll send you one of my custom ones that are better than stock.
Please elaborate,(better accuracy?)
Always nice to know what's out there.
Posted by: saigon71 Jul 14 2016, 07:02 AM
http://www.ebay.com/itm/Porsche-Sensor-Cylinder-Head-Temperature-70-76-914-4-914-6-0280130012-/222115129865?hash=item33b717ea09:g:g3oAAOSwlfxXFkex&vxp=mtr
Price is nuts
That is astounding..
I bought the following on ebay for 23.70 last Aug. It had sold last at 74.95 :
http://www.ebay.com/itm/361069640496?item=361069640496&viewitem=&vxp=mtr
Think I paid around $20 for an 012 a few years back from ebay. I guess the supply is drying up again and sellers are getting greedy.I'm quite curious about McMarks CHT - it may be the best solution now.
Posted by: jim_hoyland Jul 14 2016, 06:31 PM
See:. http://www.ratwell.com/technical/TempSensorII.html
Useful info on a variety of related topics too
Posted by: McMark Jul 15 2016, 08:24 AM
The stock sensor is some spring based variable resistance setup. I don't really know how it works, and I'm sure for it's time it was the status quo in terms of technology, but nowadays we have thermistors. Solid state components.
I had two stock sensors go out on my turbo car, possibly due to heat, but regardless it's really not a component that should fail.
I found a unit that matches the stock heat-resistance curve and embed it into the shell of a stock unit. Which reminds me, I'd need core sensors to build off of.
Posted by: Mueller Jul 15 2016, 09:09 AM
The stock sensor is some spring based variable resistance setup. I don't really know how it works, and I'm sure for it's time it was the status quo in terms of technology, but nowadays we have thermistors. Solid state components.
I had two stock sensors go out on my turbo car, possibly due to heat, but regardless it's really not a component that should fail.
I found a unit that matches the stock heat-resistance curve and embed it into the shell of a stock unit. Which reminds me, I'd need core sensors to build off of.
Hey Mark,
Can this sensor be used with Megasquirt installs?
Posted by: stugray Jul 15 2016, 10:02 AM
connect the sensor wire to the input of a switch with the output of the switch hooked to GND.
Warm up the motor with the switch open, and when it is warm, flip the switch closed.
As the CHT warms up it's resistance approaches zero ohms (a 'short' to GND).
The switch can simulate this.
If someone knows the exact resistance of the CHT when warm/hot, you can put a fixed resistor of that value on the output of the switch.
Not a permanent solution, but it would get you driving again.
Posted by: Marty Yeoman Jul 15 2016, 10:18 AM
I like the way you think.
Posted by: McMark Jul 15 2016, 10:34 AM
Can this sensor be used with Megasquirt installs?
Works on mine.
Posted by: djway Jul 15 2016, 11:52 AM
The stock sensor is some spring based variable resistance setup. I don't really know how it works, and I'm sure for it's time it was the status quo in terms of technology, but nowadays we have thermistors. Solid state components.
I had two stock sensors go out on my turbo car, possibly due to heat, but regardless it's really not a component that should fail.
I found a unit that matches the stock heat-resistance curve and embed it into the shell of a stock unit. Which reminds me, I'd need core sensors to build off of.
I have the unit that would not allow the car to work at all I can send you and purchase one of yours.
Let me know how to get one of yours and I can send you the core.
Posted by: djway Jul 15 2016, 12:12 PM
Since I have your attention 
After putting in the CHT and adjusting the AFS wiper the car idled fine and stopped belching smoke. The next afternoon I put a timming light on it just to confirm advance before taking for a longer drive. Now the car idles around 600 rpm and the adjustment on the throttle body wont bring it up much at all and there is a bit of smoke again.
I did tear apart and reassemble the throttle body and I am thinking I may have the butterfly in a bit off. Full disclosure about a week ago I knew nothing about FI or L-Jet or even how to use a multimeter. Luckily I learn rapidly and was able to get it running again but lack of experience in a hindrance in knowing which spot to look.
I did have some mean backfires the first day I worked on it so I guess that could have damaged something.
If I am not successful with the throttle body, what else should I do?
List so far.
Multi vacuum tube leaks and tear in boot repaired. No more can be found.
Timing correct.
Valves correct.
All 5 injectors pulled and left under pressure for several hours, no leaks.
All 5 injectors have proper resistance. The 4 in the heads at 3 ohm and the cold start valve at 4 ohm.
Fuel pump operates correctly and at proper pressure, a steady 36lbs.
Full throttle switch operates properly.
Aux air valve closes and re opens but I am not sure if it opens completely as I have never looked at another for comaprison.
Timed thermal sensor is giving the proper resistance signal, and again cold start valve not squirting when it should not.
The car accelerates properly and manual movement of the AFS sensor does not help idle.
All I can think of is I did something a little off in the throttle body. I can manually open it slightly and it idles fine. If there were an idle screw I would be OK right now, theoretically. I can create a small vacuum leak and it idles right up.
Any other thoughts out there for this rookie?
Thanks
Posted by: catsltd Jul 15 2016, 01:55 PM
Since I have your attention
After putting in the CHT and adjusting the AFS wiper the car idled fine and stopped belching smoke. The next afternoon I put a timming light on it just to confirm advance before taking for a longer drive. Now the car idles around 600 rpm and the adjustment on the throttle body wont bring it up much at all and there is a bit of smoke again.I did tear apart and reassemble the throttle body and I am thinking I may have the butterfly in a bit off. Full disclosure about a week ago I knew nothing about FI or L-Jet or even how to use a multimeter. Luckily I learn rapidly and was able to get it running again but lack of experience in a hindrance in knowing which spot to look.
I did have some mean backfires the first day I worked on it so I guess that could have damaged something.
If I am not successful with the throttle body, what else should I do?
List so far.
Multi vacuum tube leaks and tear in boot repaired. No more can be found.
Timing correct.
Valves correct.
All 5 injectors pulled and left under pressure for several hours, no leaks.
All 5 injectors have proper resistance. The 4 in the heads at 3 ohm and the cold start valve at 4 ohm.
Fuel pump operates correctly and at proper pressure, a steady 36lbs.
Full throttle switch operates properly.
Aux air valve closes and re opens but I am not sure if it opens completely as I have never looked at another for comaprison.
Timed thermal sensor is giving the proper resistance signal, and again cold start valve not squirting when it should not.
The car accelerates properly and manual movement of the AFS sensor does not help idle.
All I can think of is I did something a little off in the throttle body. I can manually open it slightly and it idles fine. If there were an idle screw I would be OK right now, theoretically. I can create a small vacuum leak and it idles right up.
Any other thoughts out there for this rookie?
Thanks
I took my 74/1.8L to a shop for timing and valve adjustment,car was quiter but had no power.
Finally did my own timing and valve adjustment car runs like a top.
Just my 2 cents.
Car also uses much less oil,and no more smoke out the exhaust.
Posted by: 76-914 Jul 15 2016, 02:26 PM
I'm of no help as I don't know LJet but I wouldn't freak out about CHT senders. Buy one of Marks thermistors. There dead nuts on or but a variable resistor from Radio Shack for < $7 and dial in the value you need with an ohm meter or turn it until you get the idle you want. 
Posted by: 914_teener Jul 15 2016, 03:18 PM
I'm of no help as I don't know LJet but I wouldn't freak out about CHT senders. Buy one of Marks thermistors. There dead nuts on or but a variable resistor from Radio Shack for < $7 and dial in the value you need with an ohm meter or turn it until you get the idle you want.
I am using one that McMark made for me to test a couple of years ago for my car which is inducted with the stock D-jet. It uses a modern thermistor that he made to test with a dedicated ground.
It is running flawlessly. I think the dedicated ground helps. I think after a few years from the heat cycling the stock CHT ground uses the body of the CHT. Over time it builds up oxidation causing resistance. My theory FWIW.
I'm not the EE that Stu is......I know enough of that shite to get myself into it and then ask for help.
Posted by: djway Jul 15 2016, 03:53 PM
I'm of no help as I don't know LJet but I wouldn't freak out about CHT senders. Buy one of Marks thermistors. There dead nuts on or but a variable resistor from Radio Shack for < $7 and dial in the value you need with an ohm meter or turn it until you get the idle you want.
I sent him a note that I have a core and would like to get one. The current idle problem is strictly air flow, I think LOL
Posted by: djway Jul 15 2016, 03:54 PM
I'm of no help as I don't know LJet but I wouldn't freak out about CHT senders. Buy one of Marks thermistors. There dead nuts on or but a variable resistor from Radio Shack for < $7 and dial in the value you need with an ohm meter or turn it until you get the idle you want.
I am using one that McMark made for me to test a couple of years ago for my car which is inducted with the stock D-jet. It uses a modern thermistor that he made to test with a dedicated ground.
It is running flawlessly. I think the dedicated ground helps. I think after a few years from the heat cycling the stock CHT ground uses the body of the CHT. Over time it builds up oxidation causing resistance. My theory FWIW.
I'm not the EE that Stu is......I know enough of that shite to get myself into it and then ask for help.
Heck I don't need to know nuttin to dig in deep LOL
Posted by: The Cabinetmaker Jul 15 2016, 04:51 PM
After hours of searching I finally found a place that provided a new part number.
Engine Cylinder Head Temperature Sensor-Bosch 802 54117 101 Around $30
It list all of the same vehicles as the old part number.
Funny that all the Porsche sellers don't seem to know this.
It made no sense that this many vehicles would have no supply
A Google search of that number turned up nothing for me. I searched # 311 906 041 A (Porsche part#) and found several places that have them in stock for around$30. All suppliers showed the part for an Audi.
https://www.audipartssuperstore.com/ProductDetails.asp?ProductCode=311-906-041-A& amp;gclid=CjwKEAjwk6K8BRDM3aCSkdCtzSQSJAA3Vf38Q60TKW9ghi7aRGdp3XoQHYpHiFky3Ufvs8
w--uFc0xoCALbw_wcB
Posted by: 914_teener Jul 15 2016, 04:58 PM
I'm of no help as I don't know LJet but I wouldn't freak out about CHT senders. Buy one of Marks thermistors. There dead nuts on or but a variable resistor from Radio Shack for < $7 and dial in the value you need with an ohm meter or turn it until you get the idle you want.
I am using one that McMark made for me to test a couple of years ago for my car which is inducted with the stock D-jet. It uses a modern thermistor that he made to test with a dedicated ground.
It is running flawlessly. I think the dedicated ground helps. I think after a few years from the heat cycling the stock CHT ground uses the body of the CHT. Over time it builds up oxidation causing resistance. My theory FWIW.
I'm not the EE that Stu is......I know enough of that shite to get myself into it and then ask for help.
Heck I don't need to know nuttin to dig in deep LOL
...."I've been thinking too much......HELP me".......
Posted by: djway Jul 17 2016, 01:11 AM
$30 I'll send you one of my custom ones that are better than stock.
I sent you a pm a few days ago. Did you see it?
Posted by: McMark Jul 17 2016, 07:55 AM
Worked from 7am to 10:30pm yesterday. Just replied.
Posted by: catsltd Jul 17 2016, 08:16 AM
Worked from 7am to 10:30pm yesterday. Just replied.
The red mark on the fan transmission side is the correct mark to set the timing at,not anywhere else.
This is for a 1974.1.8L.I leave it to forum to confirm.
Posted by: Jeff Bowlsby Jul 17 2016, 08:53 AM
Which reminds me, I'd need core sensors to build off of.
Could these be made with a properly sized/threaded bolt, with a drilled out cavity and make them new?
Posted by: McMark Jul 17 2016, 09:27 AM
If this was a newer, more popular car I could have a box of blanks made up. But it's not worth it for 10-15 a year.
Posted by: stugray Jul 17 2016, 11:25 AM
M10x1.00 bolts aren't easy to find, although they are out there. And then there's the matter of most M10 bolts having a 15mm or 17mm head. But even if I did find the perfect bolt supplier, there's still the matter of drilling being relatively time consuming.
If this was a newer, more popular car I could have a box of blanks made up. But it's not worth it for 10-15 a year.
Arent brake line fittings 10.0X1.00 and already have a hole drilled through them?
$1.89 ea at Belmetric or many of us (like me) will have about 50 old ones laying around attached to old busted brake lines.
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