From what I've read on here, sounds like it could be the purge valve. Does that make sense???

 

Since I'm getting no response on this, let me see if I can clarify a bit. This problem just developed as the weather turned warm, but I'm beginning to think maybe that had nothing to do with it. It takes a while to start when cold, in the morning -but not bad. If you shut it off, wait a minute or so and start it back up, it fires right up. It's only after you drive a while, then shut it down for maybe 20-30 minutes, or even a hour or two, that it really has to crank a long time before it will start. It seems like it's not getting enough fuel, or not getting it fast enough. (or maybe it's flooding?) Once it starts, it runs fine. It has 165,000 miles on it. I've recently replaced the fuel pump and the fuel pressure regulator, plus the infamous crankshaft position sensor. It has new battery and alternator, and relatively new sparkplugs. I've got a camshaft position sensor and a purge valve. Should I try them, or am I barking up the wrong tree? Come on guys -give me some input here ...............................

 

I've recently replaced the fuel pump and the fuel pressure regulator

OK, sorry. I missed that bit

 

Tim,
Looks like you have made several repairs, all of which could be
the cause of your hard start. Do you have any diagnostic trouble codes getting set during
all this "Turbulence". It would almost be certain that they are there, didn't see any comments
on codes. If you do not have any stored codes, perhaps the purge valve or cps could be
causing slow start. In all your repairs, have you verified the pressure is as required?
Sometimes faulty "New" components work their way into the supply chain. I would
be curious as to the fuel rail pressure value, say close to 47 psi.


Paul

 

I doubt it's the purge valve, my symptoms were nothing like yours when my purge valve failed. Saying that, since you have the purge valve in hand, replace it. It' a 10-minute job.


Go back and check your connections from the prior work as well and see if all the codes are clear.


Bruce

 

I'm sorry I forgot to mention, it has never shown any check engine light or trouble codes. My mechanic installed the fuel pressure regulator the other day and he said he checked and the pressure was good. (I'm not sure what it was) Yesterday, we installed the camshaft position sensor. I drove it a while, then shut it off for a few minutes and started it back up. It started good, but then the check engine light came on for the first time ever. I hooked up my scanner and it showed the code for the camshaft sensor. I figured it was just because I had removed the old one, so I erased the code. Today my wife drove it all over town all day. It seemed better, but today was unseasonably cool. The check engine light never came back on. The verdict is still out on whether this helped or not. I still have the purge valve and a throttle position sensor that I haven't installed. My mechanic doesn't think it could be either of them. I'll let you know if any improvement has been made, Thanks for your input.

 

Well it's still not fixed -after the camshaft position sensor. The weather warmed back up today, and it will have to crank for a good 20 seconds or so, to start. Then when it finally starts, it will die unless you immediately rev it up. Then, turn the key off then back on and it fires right up. Still runs fine and no trouble codes. Seems like the warmer the weather, the worse it gets. I'm baffled ..........

 

Does your diagnostic tool allow you to view the engine sensor data while the engine is running or is it just a basic code reader?

Perhaps your engine control temperature sensor or it's wiring is faulty. That could cause the engine computer to inject too much fuel when you try to start the engine when it's warm. The ambient air temperature shouldn't have much influence on starting though.

If your diag tool let's you view engine sensor data, check the value of the engine temperature an make sure it's showing a plausible value.

Regards.

Scottie.

 

It's a wi-fi scanner. It shows engine temp at startup around 170 (but it had just been running) -then it warms up pretty quick to around 190. I would have to check it under the exact circumstance where it is a hard start -after it sits for an hour or so. I just installed the purge valve, since I had it anyway. We'll see tomarrow if that helps.

 

no change, Still not fixed.

 

Your temperature readings look OK, so the other thing I'd suggest you take a look at is the fuel pressure regulator on the fuel rail. Sometimes the rubber diaphragm inside the regulator splits and causes fuel to leak into the vacuum line after the engine is shut down.

If you start the engine shortly after shut down the engine will start up normally because it usually takes a while before the fuel starts to leak into the vacuum port. It you leave the engine shut down for longer, the fuel will have leaked into the vacuum port and get drawn into the inlet manifold when you try to restart causing an over rich mixture. So, similar symptoms to what a failed ECT sensor would cause.

First check to do is pull the vacuum line off the regulator and have a good sniff to see if you smell petrol. Next, pop the line back onto the regulator and take the car for a test drive. When you shut the engine off, remove the vacuum line again and watch to see if fuel starts to leak out the vacuum port. Don't be in a rush. It can take a few minutes depending on how big the split in the rubber diaphragm is.

Scottie.

 

He's already replaced the fuel pressure regulator-in case you think the new one is bad too.

 

Yes the fuel pressure regulator was our 1st suspect. We didn't do that test, but we did find a crack in the little hose that went to it, so we replaced that too.

 

coolant temp sensor maybe? also check for intake leaks, and vacuum leaks. sounds like the ECM is dialing back the fuel too much under hot start conditions, and it uses the coolant temp sensor to determine this value...

 

I have a similar problem with my 2003 2.7L. Changed the crank sensor with OEM part and the first few starts were normal. Then back to hard starting again. I bought a coolant temp sensor but just haven't installed it yet. I might do that today. I'll let you know if it fixes my problem.

My hard start problem was slightly different. Sitting cold (and actually the colder the temp, the better it would start), it would mostly start up fine. Driving was also fine although I did get the crank sensor code with the CEL but I hope I'm past that now. If I drove it then let it sit, even for 15 minutes or so, it would be hard to start again. And hard start would be 5 seconds or so of cranking then it would start. If I started it within 15 minutes, it was fine.

I read the other user's comment about the fuel pressure regulator and I do remember taking the vacuum line off of that when I replaced my valve cover gaskets a few weeks ago and there was a little bit of fuel in the hose. That might be part of my problem too.

Keep us all posted on your situation as this seems to be a common problem with Hyundais.

 

I bought a coolant temp sensor but just haven't installed it yet.

Before fitting the new sensor, why not use it to see if the engine temperature is what's causing the problem. After you've driven the car and the you have your hot start problem, disconnect the hot sensor on the engine and plug in your new cool sensor and see if the engine starts normally when the cooler sensor is connected.

Just a thought.

Scottie.

 

I spoke today with a mechanic that worked for the past 10 yrs. at a Hyundai dealership. He never mentioned engine temp sensors, but he said a common problem he remembers having on these was the evap vapor cannister would get raw fuel in it (instead of just vapors), and they used to replace the canisters. I told him I replaced the purge valve and he said that may not be enough.

 

he said a common problem he remembers having on these was the evap vapor cannister would get raw fuel in it

It would be easy to eliminate that as the cause. Simply remove the hose on the canister side of the purge valve. If the engine starts OK with the hose removed then that could be the problem.

Scott.

 

How do you tell which is the canister side? There is an arrow on it. Is that pointing away from the canister or towards it?

 

There are two hoses on the valve. One goes to the engine and the other goes to the canister at the rear of the car. Follow the hoses and see where they go. I'd imagine that the arrow points in the direction of vapour flow, so the canister would be on the tail end of the arrow.

 

It's hard to tell, as all the hoses are behind the engine where you can't see. I assumed the arrow would point away from the canister, though, so I disconnected the hose on that side of the arrow. It shouldn't matter anyway -either hose would cut off the evap system. I started it up. It started a bit difficult, but I figured maybe 'cause the raw fuel was already in there. I let it run a few minutes then shut it down. I waited a full half hour, and it's 80 degrees now. I went back out and hit the key again -it fired up instantly, just like it used to! I'll have to test it out tomorrow, under more realistic everyday conditions. But maybe we're on to something ............I guess what we're trying to determine is -is it getting too much fuel or not enough on these hot starts. What would happen if I drove it some with that hose disconnected? Would the computer freak out or what?

 

It shouldn't matter anyway -either hose would cut off the evap system.

No, it does matter because removing the hose on the engine side of the valve will cause a big vacuum leak. I think you removed the correct hose on yours though.

 

I don't think it would do any harm to run it with the hose off for a while...for testing purposes. It will probably bring the CEL on though.

Having said that, the tank purge system over here in the UK is quite different to the more complex system employed on your side of the pond. We very rarely get evap/purge trouble codes over here but there seems to be posts on the forum every other week about purge codes from owners in the US.

 

Well, I left it off and drove it some. Eventually, as the day warmed up and it sat for a while, it did the hard start thing again anyway -so I hooked it back up. I may pull the canister off and see if it's got fuel in it, and maybe I'll try that temp sensor. I don't know -I'm running out of ideas.

 

Just to update everyone, the hot start problem ended up being the engine temp sensor. After replacing almost $400.00 worth of stuff that wasn't broke, that fixed it.

 

I had a similar problem and was the camshaft sensor, may be you need yo check yours crankshaft and camshaft sensor.

Enviado desde mi R1 HD mediante Tapatalk

 

Having the same issue Tim, 2004 2.7, does the engine temp sensor also control the temp gauge on the dash?

 

Originally Posted by tim robinette View Post
Just to update everyone, the hot start problem ended up being the engine temp sensor. After replacing almost $400.00 worth of stuff that wasn't broke, that fixed it.

Having the same issue, 2004 2.7, does the engine temp sensor also control the temp gauge on the dash?
Thanks

 

does the engine temp sensor also control the temp gauge on the dash?

Generally on Hyundai engines there are two sensors inside the one housing, one sensor for the gauge & one for the engine PCM.
So although it is the one component, a fault with the engine PCM side of the sensor won't effect the gauge and vice versa.

 

Thanks, I ordered the purge valve solenoid. Although I did not experience the at a gas station after filling up, I'am experiencing the same type of starting issue as described in this post. Ran the car about 10-15 miles it was at rest for about 30-40 minutes and experienced very rough starting. Parked the car in the garage after returning from trip went back about 20 minutes later again rough start but this time since it was in the garage a distinct smell of gas was present which lead me to start at the purge valve.
Any thoughts?

 

I had the bad purge valve problem and it always seemed to happen after fueling up.

First step is always scan for codes, even if no mil light.

If no codes, the most common hot soak issue IIRCC on the 2.7 is the crank position sensor.

SBR711 says you can often see fraying or signs of wiring wear on these sensors when they go bad.

Free advice is worth everything you pay for it. Purge valve is a wear item, I have eventually replaced it on 5different hyundai I have owned.

Cheers Mark

 

I replaced the crack sensor about 2 years ago and they wires were frayed but it was functioning properly. The manufacturer I used was standard ignition from Rock Auto.