coolant temp sensor causes 6bolt not to start..?

[98mitsubishigst]

Explain this one to me.. My new DD, has the 6 bolt swap done.. and if i leave the temp sensor in the car refuses to start after it stalls out..

It'll just crank and crank and crank..

But if i take that sensor out, it'll fire to fine and run fine..

Explain that to me!

Also this wiring harness on my 6 bolt is totally hacked up.. The last owner mistreated this car so bad..

 

[ericemery]

I am dealing with a similar issue. Only mines a 91 with a trashed harness. The good news is, those sensors are cheap. 20 bucks or so from advanced. Are you using the 2g ECS or the 1G ECS? (I dont know that it makes a difference though.)


If your not sure that the sensor is bad. (sounds like it is to me.) you can test the sensor with a multi meter. I dont remember exactly what ohm values your looking for though.

 

[954TalonTsi]

I had the same problem. Make sure theres no short in the wire. I replaced mine only to find out it was a short. Im not sure why itd start without it though...

 

[Cassanova122407]

as far as i can tell it is a saftey measure thru mitsu.

 

[98mitsubishigst]

Well i have a hacked up 2g wiring harness from last 2owners.. i have replaced literally almost everything besides the knock off turbo and BOV.. New motor/trans all that jazz.

So i should check the measurements of volts on the sensor? do you think its wiring? or the sensor itself?

 

[jaysonatticus]

Sounds to me like its a wiring issue. Throwing any codes? I'm having similar issues with my car, but its electrical all around. I'm in the process of "starting" a wiring harness swap as my harness is trashed. Keep us up to date

 

[Hal]

Without a working sensor the ECU sees the temp as something along the lines of -74f (IIRC)

So the cold start fuel enrichment dumps too much fuel.

It might start, but usually not.

 

[kmarttalon]

hmm mine starts, i forgot to plug it in then my temp gauge didnt work but still started and I am not sure though I would start looking for a used harness

 

[SexyDSM95]

Without a working sensor the ECU sees the temp as something along the lines of -74f (IIRC)

So the cold start fuel enrichment dumps too much fuel.

It might start, but usually not.

Correct, the temp sensor must be seen by the ECU or the car won't start.

Some background info - newenginewontstart [ECMTuning - wiki]

Not saying you have a Blown ground sensor, but definitely worth checking the harness. With my 6-bolt swap I found the tab that locks onto the sensor was busted so I wasn't getting a true connection. It would just slide off slightly. Reading your profile, you do have DSMLink, so you can just follow the instructions in the link I provided and do the ECU stream to see if you have any funky readings when the car decides not to start. That should point you in the right direction.

hmm mine starts, i forgot to plug it in then my temp gauge didnt work but still started and I am not sure though I would start looking for a used harness

There are two sensors on the lower housing. One is for the ECU (the larger one), and the other is for the gauge (the tiny one). The one for the gauge can be off and the car should start no issue, it's the larger plug (to the left of that) for the ECU that can be issue.

 

[92AWDHX40]

With my 1g with a bad sensor it wont start, found that out in 97 when my 1ga had problems.

 

[sparky1987]

I just went through the same thing with my car and it was causing it to just dump fuel. It would start but I had to hold the pedel to the floor and crank on it forever it would start and usually throw a fire ball out the exhaust. So id say go with a temp sensor. And as far as the wiring id definetly start looking through the harness and see if the wire is bare or broken somewhere. I had the same problem with my current car the previous owner was a for lack of a better word idiot he treated this car horrible.

 

[1badnova]

Correct, the temp sensor must be seen by the ECU or the car won't start.

Some background info - newenginewontstart [ECMTuning - wiki]

Not saying you have a Blown ground sensor, but definitely worth checking the harness. With my 6-bolt swap I found the tab that locks onto the sensor was busted so I wasn't getting a true connection. It would just slide off slightly. Reading your profile, you do have DSMLink, so you can just follow the instructions in the link I provided and do the ECU stream to see if you have any funky readings when the car decides not to start. That should point you in the right direction.

There are two sensors on the lower housing. One is for the ECU (the larger one), and the other is for the gauge (the tiny one). The one for the gauge can be off and the car should start no issue, it's the larger plug (to the left of that) for the ECU that can be issue.

I believe I'm going through this very problem with a car I just picked up. ECMtuning mentions it could be a burned ground off pin 24 or under IC101 also, does anyone know where that is? I've been searching for hours trying to find a diagram of a 1g ECU but only am coming up with pinouts.

 

[dalesocks]

If no voltage is signal back to the ecu the ecu will run with out that input. If the sensor is bad or short it could signal a voltage that is not in a range of the ecu map. Just my theory

 

[codeofdastreets]

With my 1g with a bad sensor it wont start, found that out in 97 when my 1ga had problems.

Had the same problem but the wire came off the clip and the car would turn over and turn over but no start. My friends were like its defenity not the coolent sensor wire and sure enough I tryed it out and connected it back and the car started right up

 

[OOO_ROB]

hmm my car has the same problem, maybe i will try to change my sensor also.

 

[CrawlinZX14]

Just change out the sensor. Its your ECU temp sensor. It tells the ecu what your engine's temp is to control fuel flow in to help prevent knock or detonation due to high heat. Replace the sending unit there and you will be fine. If you can unplug the sensor and its OK, but plug it in and its bad, you are likely getting a false ground in the sensor and its grounding to the water housing.