Spazz698

Not sure whats going on with my motor now... the SES light has been on for as long as Ive known the car to exist (so about a yr) I finally pulled the code and it's code 15 (low temp/high voltage @ the coolant sensor) so now I replaced that, SES still on. I didnt replace the pigtail so I assume that's the issue. So now that I replaced that sensor my car backfires, and from what it sounds like the backfire is in the intake not exhaust (it just happened to backfire while my head was under the hood checking for leaks fro mthat sensor) My car's been bogging down when you romp on it and the smell of gas is there when it bogs down or when you first start it. It backfires usually when I shift from 2nd to 3rd and the inital start of the day. Compression is fine but I swear it's running rich, esp considering at the moment Im getting ~16mpg anywhere.

oh and I did have my dad help me get the old sensor out since it was torqued down pretty well + sealant...he broke those 2 TINY black plastic tubes right above the coolant sensor going into the intake. No idea what they're for, if anyone could inform me that'd be great!

bru333

2 tiny black plastic tubes = sounds like the 2 vacuum plastic tubes to the throttle body? Top center of the photo.



If that's them you have a vacuum leak, you need to fix those. You can patch them with washer fluid hose.

Spazz698

Those would be the ones. I'll get on that as soon as I can, thanks!

[edit] Hey out of curiosity would I be able to tape those back temporarily? I tried putting them back where they were to see if the break was clean and they seemed to seal right up, just wont stay in place after a bump. Chances are I wont get the chance to replace them til sat since Im working 10+ hr shifts the rest of the week.

2_point8_boy

You have no other codes, right?

The reason I ask is because if you lose the ground to the coolant temp sensor(ECT) then it'll read 5V at the computer all the time and make it run rich, which could cause intake firing if it's bad enough.

SOmething you might also want to check is the IAT sensor in the Intake "Y." If the light comes on as soon as you start the car, then it might have something to do with that sensor because when the car is cold, the 2 should be exactly the same.

Here's what I suggest. Take a DIGITAL multimeter, not an analog one and turn the ignition but do not start the car. Take a couple of paper clips and backprobe the wires leading to the IAT, then read the voltage at the ends of the paperclips.

Now do the same thing with the ECT. Do this when the car is dead cold and the 2 readings should be darn near identical. Then let me know the voltages and the approximate outside temperature when you tested it and I will look up the values to see if they are within spec.

Spazz698

Yeah that arises a small issue- my dad has my multimeter (I do have one, got it since I finished ASE training in electrical) as my job doesnt require it and his does. Not only that, he has the next 2 days off, so no access it that any time soon.

I have a feeling the ground is bad on it but I dont wanna trace the wires to figure out which is which (me and wiring diargams only go so far, being dyslexic doesnt help a lot either) Cuz I wanna see if I splice and ground it elsewhere if the light will go off (and yes that is the one and only code coming up) I knew all that 2g amp wire that came with the car was gonna be put to good use! lol j/k

2_point8_boy

You're not gonna want to take the sensor directly to ground. You have to find out if it's open between there and the computer. The wiring goes there for a reason, ya' know.

Spazz698

theres a lot of shady wiring on this car, ie my gauges light up by pressing the brake pedal (so do the parking/marker lights) The brake light used to stay on when the right turn signal was on, the issue with fixing that is I have a custom box sitting in the trunk (came with the car) and the thing is proving to be a ***** to get out thanks to the hatch cover clips

but I am in the process of taking ase training, electrical was the first one Ive finished, so I do know I can rewire the sensor alone, given I find out if there's any resistors/fuses/etc on the + end

2_point8_boy

I know that you are taking the ASE training, and take it from another certified tech, don't assume that it's that easy. I've been there, and you want to take a good hard look at the wiring diagrams, figure out how things are wired, and then find your problem without taking shourtcuts. It will come back to bite you later. Take the time to do it right.

The computer uses the ground lead of the ECT to determine the signal from the sensor. if you just take it to ground outside the computer, then you'll have hard starting problems and get codes all over the place. You'll be chasing thoses down later while your real problem was with the shortcut wiring job you took before. I've seen a lot of people do it, that's why I'm warning against it. Don't take it personally.

Blue1989RS

I broke my black tubes as well. To fix them, I used some thick wall heat shrink and was carefull not to shrink it shut.

Spazz698

I was told sometime ago (before I actually had a camaro, this was when my bf had 2 or 3) there was 2 coolant sensors but Im only seeing one on the wiring diagram for my car- didnt realize my tps was connected to the ground either. Or the mats. Now Im wondering if the ground is bad to all 3 since im still dumping gas into the motor (Im starting to really hate the smell of raw fuel) but wouldnt a code pop up for that? The grounds to all three meet at one spot then go to the ecm, so Im thinking replacing that wire and going from there. Im not looking forward to hunting down where the wire goes from the temp sensor to the tps/mats. And dont worry I didnt take it personally, I tend to talk (or type in this case) before I think, but when it comes to working on a car I do check out the wiring diagrams before I touch anything, I just spout ideas before I look to see what'd be the best/right way.


Thanks for that tip on the heat shrink with those tubes, I didnt even think of that, Ive just about given up since all the junkyards Ive been to that have camaros they're either missing or broken too

Spazz698

hmm hey dumb question, but if my temp sensor was bad/not not receiving the right voltage wouldnt the temp gauge be wrong too? That gauge works fine, the inital startup I learned it has a voltage spike causing it to jump to the top (and getting stuck) then reads normal once the needle is moved. Unless of course its controlled by a diff sensor

2_point8_boy

The temp guage is controlled by a different, single wire sensor in the rear of the right cylinder head. The ECM uses the 2-wire sensor at the front of the intake manifold.