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Started misfiring and oil pressure shot all the way up...

Old 10-06-2011, 04:12 PM
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Default Started misfiring and oil pressure shot all the way up...

I've been having misfire issues. Especially at idle. I changed the plugs, coil, and cleaned the IAC and throttle body. It always starts missing at random times and today it decided to on my way home. Only this time I noticed that the oil pressure shot all the way up so I pulled over, turned it off, and checked the oil. The oil smells like pure gasoline so I had it towed home. Any idea on what could cause this? Injectors?
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Old 10-06-2011, 05:50 PM
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The first thing I'd check is the fuel pressure regulator, it could be building up to much pressure, pull the vacuum line and start it to see if fuel comes out
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Old 10-06-2011, 09:56 PM
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Originally Posted by tcountry View Post
The first thing I'd check is the fuel pressure regulator, it could be building up to much pressure, pull the vacuum line and start it to see if fuel comes out
I'll try that in the morning. What should I be looking for?
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Old 10-07-2011, 05:28 AM
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Put a fuel pressure gauge on the schrader valve on the fuel rail. With an 00, you should have 49 psi, plus or minus 5 at idle. Many big box parts stores will rent you the gauge.
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Old 10-07-2011, 09:26 AM
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Originally Posted by tjwalker View Post
Put a fuel pressure gauge on the schrader valve on the fuel rail. With an 00, you should have 49 psi, plus or minus 5 at idle. Many big box parts stores will rent you the gauge.
Thanks for the information. I already ordered injectors. They should be here today but I don't want to put them on and waste 300 dollars. I am a college student so that's a nice chunk for me. I'm headed to advance auto parts now.
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Old 10-07-2011, 11:35 AM
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I was told that it could be the coolant temperature sensor going bad and telling it to send to much fuel. Can anyone confirm if this is possible?
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Old 10-07-2011, 06:02 PM
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Originally Posted by 00_XJ View Post
I was told that it could be the coolant temperature sensor going bad and telling it to send to much fuel. Can anyone confirm if this is possible?
Changed it anyway, didn't work.

I'm supposed to be on my way home for fall break and I can't leave until this thing is fixed. It's worse than ever now. Idles fine, shutters when put in gear, and the oil pressure shoots up slowly as soon as you give it gas. I've tried everything here with no results. Any other ideas?
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Old 10-07-2011, 07:23 PM
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Take the vacuum line off that goes to the regulator and start it. You will probably find that it leaks gas out of the vacuum fitting, meaning that it is dumping gas into the engine.
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Old 10-07-2011, 10:21 PM
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Originally Posted by andyg
Take the vacuum line off that goes to the regulator and start it. You will probably find that it leaks gas out of the vacuum fitting, meaning that it is dumping gas into the engine.
If that's the case, what does that tell me? That it's the regulator?
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Old 10-09-2011, 04:29 AM
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Harbor frieght has fuel pressure testers cheap.
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Old 10-09-2011, 06:23 AM
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Originally Posted by 00_XJ View Post
If that's the case, what does that tell me? That it's the regulator?
Correct. this happened to me once.
Be sure and change your oil asap after you fix the trouble, gasoline infused oil is no beuno for your mains
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Old 11-03-2011, 08:34 AM
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I found the problem. One of the wires coming from the computer to the coil was shorting out. Fixed that and it runs like a champ.

BUT now I have another problem. Ever since I fixed that, it will only idle for about 30 seconds before it dies. There's no check engine light or anything. It has made quite a few people mad at red lights and is irritating me. The coil is brand new, the plugs are brand new (Autolite Platinums) and my misfire is gone. I'm stumped.
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Old 11-03-2011, 08:35 AM
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Is it ONLY at idle when it dies? Or does stalling occur at other speeds?
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Old 11-03-2011, 11:01 AM
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Originally Posted by tjwalker View Post
Is it ONLY at idle when it dies? Or does stalling occur at other speeds?
Only at idle. It does it every time when the engine is still cold and only sometimes when it's at normal temperature.
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Old 11-03-2011, 05:43 PM
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There are a number of possibilities for stalling, but one of the primary ones is a "marginal" battery. And yes, you CAN have a battery that is strong enough to start the engine, but marginal enough to give the engine management system fits and create "stalling" Have the battery LOAD TESTED. Any parts store will do this for you for free.

It could be something else, but failure to verify the battery early in the troubleshooting process is a mistake.
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