car is slowly killing me... *UPDATE* fixed! Options

[Scott-thundercat]

Okay so i've run the gammit of crap for this car. new cap, new rotor, new points, new condensor, new plug wires, new coil, adjusted valves, replaced BENZ fuel pump with late 914 fuel pump (thinking maybe too much pressure was problem). replaced all fuel hoses, replaced fuel tank (no kinks in lines), replaced fuel filter.

questions are thus- when i start the car it runs, it runs rough but it still runs. let it warm up- can drive it while cold- when it warms up it dies and wont restart for quite some time. plugs dont have oil on them but do have some signs of way too much fuel. this sounds like it could be the CHT sensor. Question- i have a black wire coming off of what looks like the CHT sensor slightly in front of the rear cylinder on the passenger side's spark plug... doesnt connect to anything- dont see where it could connect to... where does this wire usually live?

also going to bypass the Cold start injector cause i think it might be leaking into the engine fueling the oil.

the engine runs quite rough (like at least one cylinder is missfiring)- until i let off the throttle from around 3K rpm- then it runs perfectly (but at 2000 RPM) for a few seconds before becoming rough and crappy again- why?

this car is slowly killing me- i've found so many problems and fixed em only to have more left. i'm going to head down to go work on it-(parked at a gas station where i limped it to while trying to drive to my new apartment).

if anyone has some great advice or wishes to help please call me at five three zero 220 four zero 33... sorry for the wierd way of writing it- dont want any autoscanners to pick it up.

Scott

[r_towle]

dude, its the CHT.

the wire from it goes into the wiring harness right next to it...kinda on top of the tin, near the rear firewall area...back of the motor passenger side.

If that is not hooked up...all of what you said will happen.

Rich

[Bartlett 914]

Okay so i've run the gammit of crap for this car. new cap, new rotor, new points, new condensor, new plug wires, new coil, adjusted valves, replaced BENZ fuel pump with late 914 fuel pump (thinking maybe too much pressure was problem). replaced all fuel hoses, replaced fuel tank (no kinks in lines), replaced fuel filter.

questions are thus- when i start the car it runs, it runs rough but it still runs. let it warm up- can drive it while cold- when it warms up it dies and wont restart for quite some time. plugs dont have oil on them but do have some signs of way too much fuel. this sounds like it could be the CHT sensor. Question- i have a black wire coming off of what looks like the CHT sensor slightly in front of the rear cylinder on the passenger side's spark plug... doesnt connect to anything- dont see where it could connect to... where does this wire usually live?

also going to bypass the Cold start injector cause i think it might be leaking into the engine fueling the oil.

the engine runs quite rough (like at least one cylinder is missfiring)- until i let off the throttle from around 3K rpm- then it runs perfectly (but at 2000 RPM) for a few seconds before becoming rough and crappy again- why?

this car is slowly killing me- i've found so many problems and fixed em only to have more left. i'm going to head down to go work on it-(parked at a gas station where i limped it to while trying to drive to my new apartment).

if anyone has some great advice or wishes to help please call me at five three zero 220 four zero 33... sorry for the wierd way of writing it- dont want any autoscanners to pick it up.

Scott

The CHT is located on Cylinder #3 passenger side rear cylinder. This bkack wire may be the wire for the CHT. Remove the cold start valve from the intake to see if it leaks. If so, plug off fuel hose. Vacuum leaks cause so many problems. Make sure there are none. Your problem can be so many things. I hope this a start for you.

[Scott-thundercat]

found a leaky fuel injector on the pass side front cylinder. found what looked like some of the pics of the CHT on the block aft of the distributor.... (clearly not cylinder HT) with a wire that went right into the wire harness... maybe oil pressure? still could not find any wires that the black one matched with. tommorow i'm going to put one of my spare fuel injectors on and see how it works. i remember looking over a wiring diagram for this car (70 1.7 D-jet) that showed a temp sensor hooked to the cold start injector as the switched ground (the cold start injector had a wire coming off that was the right length to match up to the CHTish thing... i put my multimeter on the CHT- and it was open- so it seems like it could be a switching ground for when it gets cold out... i dunno- very odd. none of the things i look at for the DJet have the same stuff as my engine...

thanks for the input guys- i'll look again tommorow in the light.

[Dave_Darling]

Most of the D-jet diagrams we have were made for the 2.0 engine. Sorry, that's just how it wound up.

There is a thermo-sensor that lives on a bracket under the manifold. That is what provides the ground for the cold start valve.

The CHT sensor should plug into a wire in the main EFI wiring harness that comes out of the "brain". Look for a single wire that comes out of the harness near where the four wires for the MPS come out of it, and where the four wires for the two right-side injectors come out. Bowlsby has a better idea of the exact places where those things branch off of the main harness, but it's in that area...

--DD

[Twystd1]

I feel your pain......

So I will give ya 500 bucks for the car...

Just my way of trying to help you out of a terrible situation....

Twystd1

[Scott-thundercat]

I feel your pain......

So I will give ya 500 bucks for the car...

Just my way of trying to help you out of a terrible situation....

Twystd1

heh heh, thanks for the offer... i'll wait a while and see... (IMG:style_emoticons/default/biggrin.gif)

thanks for the info on where to look- i shall check it out today.

Scott

[army dude]

replace motor with cheby three fitty!!! I got a tree fiddy!! runz grate!! I'm 8000 miles away from it, but eet runz grate!!

Ian in Iraq...again

sorry I can't any other way, go carbs??

[Jeffs9146]

The CHT sensor should plug into a wire in the main EFI wiring harness that comes out of the "brain". Look for a single wire that comes out of the harness near where the four wires for the MPS come out of it, and where the four wires for the two right-side injectors come out. Bowlsby has a better idea of the exact places where those things branch off of the main harness, but it's in that area...

This is your first problem! You cant get any further until you fix the CHT. That wire needs to be hooked up for the car to adjust the fuel/air mixture when it warms up.

I bought a car from a guy who put a new motor in and never could figure out why it wouldn't run when warm. He put a new harness, brain, fuel/air valve and then gave up and sold me the car to me for $1700. I found that the CHT had stripped threads so it tested ok but sent out in-acurate signals to the computer.

Jeff

[So.Cal.914]

More specificly...Webers. (IMG:style_emoticons/default/smile.gif)

[Jeffs9146]

More specificly...Webers. (IMG:style_emoticons/default/smile.gif)

That will work but it is a hell of a lot more $$$$$$$ than hooking up a wire or replacing the CHT.

Jeff

[banger]

Here are some pics that might make it easier to see where it is, and where it goes. There should be a rubber seal around the wire, missing on mine though.
(IMG:http://www.libraunlimited.com/914pics/cht2.jpg)
(IMG:http://www.libraunlimited.com/914pics/cht1.jpg)
(IMG:http://www.libraunlimited.com/914pics/cht3.jpg)

[Dave_Darling]

There should be a rubber gromet in the hole to keep the cooling air in. I'm not sure how important it is, but it certainly is not a bad thing to have.

The wire appears to be plugged into the EFI wiring harness, right about where it should be. But it really should be insulated; if that bare bit of metal at the end of the connector touches a ground the mixture will go full-rich for as long as that's grounded...

--DD

[Scott-thundercat]

okay couldnt find a loose wire anywhere, kept looking around. finally saw a small crack in the harness and figured maybe it was there for a wire... cut the whole thing open and searched around some in that area and found a wire! connected it to CHT- worked great!!! started right up- no more smoke anymore!!! let it run for a while- still ran when warm! adjusted the dwell and timing a bit, drove it around the parking lot- ran and drove great... then i stepped on the gas and it died... couldnt figure out why- then i didnt hear the fuel pump- checked the ground- and somehow when i gassed it i guess the air cleaner shifted and unhooked the ground- hooked it back up and no problems- cant wait to drive it home tommorow! thank you all for the help, and thanks for the phone call- you saved me a lot of time and backache!!!

Scott

[BigDBass]

(IMG:style_emoticons/default/smilie_pokal.gif)

[Jeffs9146]

cut the whole thing open and searched around some in that area and found a wire! connected it to CHT- worked great!!!

(IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/piratenanner.gif)

I feel good about that!! I am glad you figured it out! (IMG:style_emoticons/default/beerchug.gif)

Jeff