2001 Tiburon Starting
My 2001 Tibby runs great! However, after driving for a bit, and shutting it off, it
doesn't start right away. It hits for a second but won't catch and run. After a
spell, it cranks perfectly. Anyone know the problem? I've checked the MAF
and the IAC, both are fine. It was suggested maybe a fuel or fuel pressure
relay was opening somewhere?
Your description is a little confusing. I think you mean that if you crank it over, the engine will not fire right up. Like it's not getting any fuel. Then after sitting for a period of time, you can crank it over and it will start normally. If you were losing fuel pressure, it wouldn't matter if the engine was hot or cold. It simply would have to keep cranking until it started. I think in your case it's an issue with cold VS hot. When engine is cool, it starts great. When engine is hot, it will not fire right up on the first try. Only after it cools for a while. You may have a bad ECT. (Engine Coolant Temp) sensor. It may be bad causing too much fuel to be injected. This would cause an overly rich fuel air mixture. You could also have a bad crank sensor as well. If your check engine light is on, I would have the codes read.
Sounds interesting and your are correct with the hot/cold thought. It would try to catch briefly but wouldn't start and only turn over continuously. However, it doesn't throw any codes. I'll check that ECT out. It has a new crank position sensor. Can you comment on the location of this sensor? TKS
The ECT sensor that is...
On most vehicles the ECT sensor is located right next to the thermostat. It's a brass plug with a connection for the temp wire.
Yes thanks. I found and changed it out. Then I drove the car about 15 minutes; shut it off and waited about 20 minutes and tried to start it. Same thing. It sputtered some but did finally catch and run. One thing to note however. A week ago I was driving to the dentist and the alt belt broke. It ran hot by the time I made it to the office. Since I replaced that belt, it has been more consistent in not starting as described. One reason I thought you hit the nail on the head with the ECT?
Take a volt meter and test your battery with the engine off. See how close to 12 volts you are. If you find it below 11.8, it may be time for a new battery. I would remove a couple of plugs and inspect them. See if they are black and sooty. This would indicate a rich fuel mixture. The only other component I can think of that may be causing your problem is a faulty MAP sensor. Is your check engine light on by chance? If so, I would get the codes read. A bad O2 sensor could also give you starting issues.
No codes are happening. I'll troubleshoot this sensor and see what happens. Could back pressure from a clogged CAT cause this? When I got the car, I had to replace the flex part of the exhaust because it had burned apart. However, I am not getting codes of any type. TKS - Keith
I've had a clogged cat before. You usually have a great decrease in power and acceleration. Especially up hills. Hard to go over 50 mph. on the interstate. So unless your car has suddenly turned into a complete dog, I don't think it's a clogged cat. Not to mention if the cat was clogged, it would be affecting the start on both hot and cold starts.
Reelin68, thanks for all your help here. I was checking the car over again for possible reasons why this starting issue existed and I came across a sensor in the air cleaner box called IAT. I cleaned it and from the appearance of it determined it was a temp sensor. I checked the ohms as I breathed on it both warm and cool air, and the resistance changed. I put it back on and haven't had the starting issue again (yet). As you suggested, I also checked the battery and it was well over 12 volts. If the starting issues repeats, I will comment further. Per chance, do you know how this IAT affects the engine?
Yes, it's the intake air temp sensor. As it sucks air in, it measures the temp and densiity. The computer then combines the fuel/air mixture ratio. If not working properly, it will make the mixture too lean or too rich. Either of which will give you starting issues. Good call! Hopefully you nailed it!
Okay, it started fine all week until yesterday then took 15 minutes to get it to catch. I believe I will get a new IAT and see if that solves it completely. A fellow employee also mentioned the positive wire and/or fusible link in the wire from the battery to the power distribution fuse box may be an issue.
I replaced the IAT sensor but car still wants to choke down when trying to start it after a short drive and a short rest. I did have to replace the battery which failed last week. I'm not sure where to go next. The fuel relay was mentioned as a possible cause?
I have heard of relays not having good connections. People usually try bending the pins out a bit to get a tighter fit. It's worth a try. Or just replace it. Very cheap part. I just looked at a ton of forums and there were a few Tiburons with the same no start issue, but as usual, nobody offered up a solution. There were some people that replaced the crank sensor, and that seemed to work. But that usually throws a code. Another guy replaced the pressure reducer on his fuel rail and that cured his problem. But that was on an Accent. Maybe you should have the fuel pressure tested. You can do that yourself with a pressure gauge. That's the only other thing that comes to mind.
Okay, this is unusual to me but the car has settled down and has started perfectly for a week now! The last part I replaced was the Intake Air Temp Sensor. I am just guessing that the cars ECU had to "learn" the new sensor and now works as designed. Thanks for all your help and input Reelin68.
Not a problem! Glad it's now working for you!
After several more repairs I am back to square one with this car. Drove about 40 miles and shut it off. About 20 minutes later it wouldn't start. It just sounds like it isn't getting fuel? After about ten minutes or so of cranking, it finally caught and sputtered slowly to a smooth idle. Once the engine is running, it is fine. It will restart easily immediately after shutting it off, but after about 15 to 20 minutes, forget it. Any new ideas what causes this?
Koolpoppa, please list off every part that has been replaced so we can get an idea of where to start. Thanks.
I have replaced the intake air sensor, the ECT sensor, the manifold and catalytic converter, the battery, idle speed control, and the fuel pressure regulator have all been replaced. I cleaned the MAF sensor. Along with these although not related is everything from the trans out to where the rubber meets the road!
Also, I had began getting a P1128 code is why I replaced the manifold. The manifold had split open. However, just this morning the code reappeared after I had to sit in traffic idling for a while.
Well since you've already replaced the manifold, cat, and fuel pressure regulator, that leaves a faulty MAF or O2 sensor. The P1128 is a fuel lean code. This is most often caused by a vacuum leak or it can also be caused by a clogged fuel filter, unmetered air entering the air intake system, leaking exhaust system, canister purge system not operating or a weak fuel pump. You fixed the manifold leak, exhaust, and fuel pressure regulator so I would suspect the MAF or O2 sensor.
Okay sounds good. It may still have an exhaust leak however, or at least it "sounds" like it does, so I'll check that. I will ohm the sensors, replace the fuel pump and filter and see what we have then.
A quick question on the exhaust: The center muffler is where the leak is. Is that muffler necessary for proper operation? I'm thinking about welding in a piece of straight pipe there.
If you mean Cat converter, sure, you can remove it and put a piece of pipe there. But, if you have to pass smog, it will fail. It may also trigger the CEL if you bypass the Cat. I put a straight pipe on my '89 4x4 and it didn't trigger the CEL.
It isn't the Cat converter. The CAT is part of the manifold that I just replaced so it has a new CAT. This "center" muffler as it is called has rusted on the connection. I'll give it a try and see how it goes.
I found that the rear muffler was stopped up pretty bad. I cut the tail pipe just past the toner and it is blowing freely now. Yet, the car still has the same original issue not starting after a short break with a hot engine. One observation I have made is that the engine compartment get extremely hot! Even the hood prop rod will burn your hand when propping the hood with it, but the engine doesn't overheat! I'll keep plugging away at it as long as I can do it without spending a lot of $$.
Okay, I'm back for another round! I have the non-starting when hot issue covered. I got the missing air filter box snap-down replaced and the correct size air filter in place. This seems to have stopped the starting issue. Now, the car will skip or "cut- out" at higher RPM'S just before shifting and also when kick- down to pass a car. Any thoughts?
From what I have seen on other forums, the problem sounds like the transmission is not shifting correctly, causing the stall issue. This is pretty common on the Tiburon. In some cases it's the kick down switch or the pulse generator. You should get the codes scanned and see what the issue really is. Tranny issues can run a lot of money in a hurry. Best to know exactly where to start.
Actually, the trans shifts fine when I accelerate at a more modest rate. The tail pipe is still off though at this point and I am wondering if that bit of missing back pressure could cause the misfire. It will also skip occasionally when cruising with control. Also, I can sit in park and rev the engine to 4.5 - 5 and it misfires.
Okay, this is my final comment here for the benefit of anyone with a similar issue. The car is running perfectly now! Read through the previous comments for a list of parts and sensors I replaced, but the last thing I did to make it purr, was getting the correct air filter, and replacing a missing clamp on the air filter box lid. I put the ORIGINAL MAF back on then did a "capacitor discharge" as described on another forum.
