Hi Scotty, big fan of your videos.
I have a 04 hyundai Tiburon GT V6 5 speed manual transmission. About 111,000 miles on it. I'm having a nightmare trying to get it running again. Bought it only for $2000.00 and yes it needed work. I was willing to put $2000.00 into it. Let's just say I went over my budget and mechanic I brought it too completely scammed me for a lot of money and left my car apart. I replaced TPS, idle air control valve, purge valve, pcv valve, fuel pressure regulator, fuel pump, fuel injectors, fuel injector connectors, two knock sensors, knock sensor connectors, maf sensor, coolant temperature sensor, air intake temperature sensor, crank and cam position sensors, timing belt replacement, water pump replacement, clutch kit with 12 pound flywheel, all 4 shocks and struts, all 4 brake pads and rotors, clutch master cylinder, both catalytic converters, ignition coil pack, new ngk plugs and wires, new denso alternator, few other things I can't remember. Here's the problem, it starts right up. It will idle fine. 30-45 mins no problem. As soon as I step on the gas pedal, it stalls out. Then it's hard to start up again and when it does start back up, it has very rough idle and then it will stall out again. I've tried to replace the ECU to see if it was that. It did the same thing. Mobile mechanic came to check it out and when he disconnected the maf sensor, it was showing on his scanner that it was still connected. He thinks it's either the ECU, which I checked and it's not that, or a short in the wiring.
Any advise or anything you can tell me that would put me on the right path of fixing this car and nightmare? Please. Thank you for your service.
You have already dumped far too much money into this thing. Cut your losses now.
Not yet
The fact that your mechanic says that there's a MAF sensor signal to the ECU when the MAF sensor is unplugged is a huge clue.
There's a long list of work done on this vehicle. A lot of wiring connectors had to be disconnected and wiring harnesses moved during those repairs.
Hyundai uses a lot of identical wiring connectors in areas which are too close together (in my opinion).
So that's something that came to mind when you mentioned a MAF signal with your MAF sensor unplugged.
I took a quick look at some of the connectors which are close to your MAF, and your VSS connector is identical.
So that's neither here nor there. Just something to keep in the back of your mind.
It's time to physically check what's going on at that MAF sensor connector.
You don't need to know anything about auto mechanics or electricity.
Go out and buy a multimeter. You can get one for under $10 on Amazon or even less if you have a Harbor Freight near you.
Your MAF sensor connector has 3 wires going to its connector.
First, tell us the colors of the 3 wires going to the connector.
Then, disconnect the wiring connector from the MAF sensor.
Turn the dial on the multimeter to DC Volts (20 volt range).
The connector to your MAF looks like this:
Connect the Black (negative lead) of the multimeter to the Negative Post on your battery.
One by one, touch the Red (positive lead) of the multimeter to each of those 3 connector terminals WITH THE KEY IN THE ON POSITION.
Write down the results and tell us what you find out.
What you should see is:
Key On, Engine Off:
Pin 1: 0V (ground)
Pin 2: 0V (signal wire)
Pin 3: 12.5V (power) ((this will be battery voltage. May be between 10 volts and 13 volts)).
I'm going to post a video of a guy doing a voltage test on the MAF sensor connector on your vehicle just to show how it's done.
Notice how he has the Black lead of his multimeter on the battery Negative Post as he probes each of the connector terminals with the Red lead of his multimeter.
Don't conclude that HIS problem is YOUR problem.
I'm just posting it so you can see how easy this test is and if a picture is worth a thousand words, a video should be worth a million.
https://www.youtube.com/watch?v=eO55i7X1UII
Sorry it takes me long to reply back. I don't get notifications from here.
Thank you for taking time to give me some ideas. The connector to the maf sensor I actually replaced just recently. Still doing the same issue. It starts fine. Will idle fine. Once I press on the gas pedal, it stalls out. It will start right up again. I actually have that same volt meter here. I will definitely do what you saying. Can't today because it's raining outside. And unfortunately my car is outside. But the colors on the maf sensor connector are brown, red, and black. I rewired it in the same order. Still stalling out. Can a clogged fuel rail or clogged fuel pressure hose make my car stall out when hitting the gas pedal? I did get a code. It's saying cam position sensor. I just replaced it. Should I replace it again?
One last question, can this stalling come from the timing belt not timed properly? Thanks for taking time to give me some advice.
Thanks for the video also. I'm gonna try that out.
Ok. I was able to check with my multi meter. I have these 3 colors on my maf. Red
Brown
Black.
Here are the readings I got for each:
Red- 12.33
Brown- 10.08
Black- 0.00
Well that's not right. You shouldn't be seeing 10 volts on that signal wire
.
The only reason you'd see that is if there were a short in the harness between that 12 volt wire and the signal wire
.
In fact, those voltage readings sound more like what you'd get from the connector on the transmission
.
Maybe pop the connector off of the transmission, write down the colors of those wires and repeat that same test you just did on the MAF connector on that transmission connector
.
Let's see if that connector gives the voltages that the MAF connector should be giving
.
Is it possible that these 2 identical wiring connectors are plugged into the wrong components?
Maf connector on a transmission??? Never heard of a maf sensor on a transmission before. My car is a 5 speed.
Sorry Im new on here and navigating threw here I hit wrong key.
But thank you for your advice. Any other ideas are greatly appreciated and welcomed.
The maf connector in question is the one on the air intake system
No.
He said you need to test the transmission connector now. (the same TEST that you performed on the MAF connector.)
His point was that they are both 3-pin connectors, and could have been mixed up.
What is vss connector?
VSS = Vehicle Speed Sensor
(Google is usually pretty good for providing meanings of acronyms.)
Ohh ok. Yes that connector is right near the transmission. Ok tomorrow I will check on that. I will check the vss too. Thank you. 👍
Sorry if I wasn't clear, Gizmo. I didn't mean to confuse you.
.
I hope MountainManJoe @mmj cleared it up
.
My point is that you have the identical 3 wire connector on your manual transmission as the 3 wire connector on your MAF sensor
.
In most cases, with those voltage results you got I'd suspect a short to power on the MAF signal wire
.
However, we're dealing with a hyundai here and like I said, they like to use identical connectors for different circuits/components
.
You had a lot of work done on that tiburon and we can't ignore the possibility that somebody may have gotten the 3 pin connector that's supposed to be going to the MAF sensor, mixed up with the identical 3 pin connector that's going to your manual transmission
.
Just to illustrate, here's the 3 pin connector that goes on your manual transmission speed sensor
.
Notice how it's identical to that MAF sensor 3 pin connector that you just got done testing?
.
Ok I been checking today and I can't find that connector on my transmission. I see a connector on the transmission but it's completely different from this connector. The connector I seen is right on top of the transmission. Is there another sensor that is on the transmission? This is crazy. My car starts right up. Will idle fine. Once gas pedal is pressed, it stalls out. Almost sounds like it's getting too much air. But everytime I go to disconnect the maf sensor, nothing happens. Isn't the car supposed to stall right out once you disconnect the maf sensor?
Disconnecting the MAF sensor connector to see if the car stalls isn't a valid test. You can find just as many youtubes where that works as you can for where that doesn't work
.
What's interesting is that your mechanic said that your MAF sensor was reading airflow at KOEO (key on, engine off) and your own test found 10.08 volts on the MAF Signal wire with the MAF sensor connector unplugged
.
To give you an idea of what the voltages on your MAF sensor signal wire should be when the connector is plugged into the MAF sensor, at idle (around 700 rpms) 0.5 volts
.
At 3,000 rpms around 2.5 volts
.
Unplugged 0 volts
.
You didn't mention if you have a scanner or not
.
If you don't, it's time to get one. You don't need an expensive one. Use the magnifying glass icon in the black banner at the top of the page and do a forum search on, Scanner
.
Scanner recommendations have been done to death here and there's some good info in those threads
.
You need to see what the computer is seeing when your Tiburon is running at idle
.
Specifically, the MAF sensor Voltage and the MAF sensor airflow data
.
Here's a pic of what that will look like. The guy has his set to Imperial measurements so he's displaying MAF airflow in Lb/sec. You'd set yours to metric to read the MAF airflow in grams/sec
.
What you should see on yours is, like I said, around 0.5 volts at idle with an airflow of around 2.7g/s
.
(Image should get bigger if you click on it)
.
.
If the computer is seeing that 10.8 volts you measured on the signal wire with your multimeter, then you have to disconnect the harness at the computer and do some tests on the harness to see if you have a short to power on that signal wire
I switched the wires like you told me to do and now my car is running good. Does not stall when I press on the gas pedal. It sounds a lot better too. Idle is more calm too. I am still getting a cam position sensor code. That I can replace.
But I want to thank everyone on here for helping me with everything. Tomorrow I will take it out for a test drive.
Thank you for helping me with this nightmare I been dealing with.
If I have any other questions, I'll definitely come back on here. Thank you all. 👍👍✌️🙏
I'm glad you got it running good and came back to let us know how it turned out
.
It's always good to rule out that some previous mechanic didn't screw up something
.
It happens more than you think.
That is true. I been stuck with my car like this for a year. But now it's not stalling out. I'm still waiting on the cam position sensor to put it in. Haven't test drive it yet because I'm waiting to put cam position sensor on and then put it all back together and test. Thanks to everyone again. If I have any questions I'll definitely come back here. Thank you.
Sell it for about $80 per ton scrap value. This is a classic example of a "Dollar chasing a dime."
If you disconnect the MAF sensor, do you still have the stalling issue?
Yes
Yes. I replaced the maf sensor 2 times. Can it be the connectors? Sorry late reply. I had a lot going on. I even put a newer throttle body. Still having the same problem