Gas smell

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undergnd
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Gas smell

Postby undergnd » Wed May 20, 2015 12:24 pm

Hi ppl,

Please, need some help. My main concerns are the gas smell and some funny behaviour while in idle.

** When the engine is cold, I have to hold the ignition key at start position for 6 or 7 seconds. In this case, before the engine starts, the car shakes, like it wants to shut off. Sometimes I need to depress the gas pedal.
** When the engine is warm, it starts normally but the tach needle goes to 2,000 - 2,200 RPM then falls to 1,200 or 1,000.
** When I drive the car at normal speeds and want to brake to 0 MPH, I use to depress the shift pedal and shift to neutral position. So I only need to press the brake until the car stops completely. In this case, the RPM falls to 1500 while the car decreases the speed. But in case the car is still moving and I only depress the shift pedal, the RPM increases to 1800 then falls to 1500. When the car stops, the RPM slows to 950 - 1000 RPM.
** From 0 MPH, at first gear and starting to accelerate the RPM decreases to 700 and increases again, then it goes increasing normally while

>> The fuel consumption is around 18 MPG combined (high traffic). I use 90 octane fuel. When I put 95 octane, it improves a bit.
>> The fan turns on before the temp reaches the middle point of the dial. It's around 2/5 of the dial.
>> The oil pressure when the engine is cold is above the middle point, once the engine is warm it starts to fall. When I depress the gas, the pressure increases, but never passes the middle point. At lights, the pressure is around 9 - 10 PSI.
>> No SES lights (it works). Anyway, trying to fix the gas smell and the idle problems, I've replaced the MAF sensor (3 months ago), the IAC (1 week ago), the CKP (it died 2 months ago) and the fuel pump (it died 2 months ago)
>> The car never shuts off, it only shakes a bit. Runs fine. At idle speed and normal temps, the RPM is 950 to 1000.
>> When installing the MAF sensor, I noticed the sticker about the ECU reflash... so after making some research, I think that I wasted my money with this part...

I'm planning to replace the O2 sensor, but don't know if it will fix the problems. What do you think?
Thanks in advance.

Beretta 88 (87) 2.8 V6 - M/T (90,000 miles)

p.s.: Sorry for my bad english


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Cliff8928
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Re: Gas smell

Postby Cliff8928 » Wed May 20, 2015 12:48 pm

Is it a raw gas smell coming from under the hood? I would check the fuel pressure regulator.


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undergnd
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Re: Gas smell

Postby undergnd » Wed May 20, 2015 1:11 pm

Hi Cliff,
Yep... it's raw gas smell. Not sure if it comes under the hood, but I can smell it while driving, while warming up parked at the street.
Where is the regulator?
Thank you!


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Re: Gas smell

Postby SuzukiGhostRider » Wed May 20, 2015 1:13 pm

Fuel pressure regulator sounds bad to me.


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Re: Gas smell

Postby Cliff8928 » Wed May 20, 2015 1:30 pm

It's sandwiched between the two fuel rails and has the vacuum line coming out the top.. The fuel lines attach to it. They can fail by having the diaphragm rupture inside and leak fuel through the vacuum port and cause some of the symptoms you are describing. If you remove the vacuum line it should be dry; any sign of fuel indicates failure.

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undergnd
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Re: Gas smell

Postby undergnd » Wed May 20, 2015 1:39 pm

Cool!!! thank you guys. I'll check it and let you know how it goes.
cheers


88 Beretta V6 2.8 M/T
Weird car in Peru, weird member in Bnet

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undergnd
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Re: Gas smell

Postby undergnd » Sat May 23, 2015 1:14 am

Hi again!
I removed the vacuum line and it's dry! Is possible that the regulator can fail without traces of fuel in the vacuum line?
I was making some research and figured out that it can also be a worn spring inside the regulator. In this case there is no visible fuel in the line. Is it right?

Some YouTube videos shows that the regulator mechanism is pretty simple: vacuum, spring and diaphragm. The vacuum pressure comes from the intake manifold and it makes the spring and diaphragm works mechanically up and down to tap/untap the fuel flow to the returning line... so... I think that the fuel flow is more related with the vacuum pressure/intake manifold than the diaphragm or spring specs.

I also found diaphragm kits on EBay... I called some local Chevy parts shops and none of them have the regulator in stock
And some questions comes to mind:
In case the diaphragm is ok... Can I replace only the spring with another one?
In case the diaphragm and spring looks worn... Can I replace those parts with similar ones?
In case the I replace the entire fuel regulator with a new one and the odor remains... are the problems related to the vacuum line and the intake manifold? In case is positive what sensor or part must I check next?

By the way, the last night while coming home, the fuel odor was really, really high and the car started to shake and felt that the engine was working rough (it never happened before), like it was trying to tell me "change the fuel regulator asap!!!"

Anyway, I'm going to another Chevy parts shops looking for the regulator.
cheers.


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Re: Gas smell

Postby SuperLbody » Sat May 23, 2015 7:47 am

Its not the regulator if you didn't see fuel. I would reinstall the old MAF and conduct a fuel pressure test. I would also recheck the installation of the fuel pump since you said you replaced. I would guess its either a leak somewhere or a very badly leaking injector which would drown the motor out when trying to start.



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undergnd
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Re: Gas smell

Postby undergnd » Sat May 23, 2015 1:29 pm

Update after my last post...
Because I couldn't sleep, at 3.00 a.m. I planned to went for a ride and test the car to check if the rough condition was remaining....

It started instantly!!! (after 12 hours parked in my house). The RPM needle reached only 1500 and started to decrease normally while the engine was warming.
Once the car started to move, I was surprised that the RPMs were very stable and decreasing to normally to 1000-1100 while depressing the clutch pedal (as stated before, it used to increase +200 RPM), so, it was working fine like never before since I own the car!!. No gas smell, no shakes...

So, I stopped the car (with the engine on) and warmed it until the fan started to work. Then I tried again. Everything was fine!!! no gas smell, no shakes, nice shifting and revving.

Everything was happiness in my heart... :Yahoo!: Until I turned off the engine and started it again... :x the RPM reached 2200 at start, started to fall slowly until 1500... then 1100... the gas smell came back, RPM increase while shifting, etcetera...

Tried the process several times turning off and on the engine... same faulty conditions.

The last test was to depress and release fastly the gas pedal while moving (in neutral position) until 4000-4500... And guess what... the car fixed itself!

So, in conclusion, the symptons happens randomly (hate randomness!!!), but if I depress hardly the gas pedal the problems are gone. Now (thanks to you all and Super) I'm pretty sure that it's something with the fuel system. I'll make a pressure test this Monday and double check the fuel pump. Anyway if I find the holy fuel pressure regulator, I'll replace it.

have a nice weekend!


88 Beretta V6 2.8 M/T
Weird car in Peru, weird member in Bnet

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undergnd
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Re: Gas smell

Postby undergnd » Tue Jun 02, 2015 2:40 am

Hi ppl,
Here is an update: The fuel smell is gone!! :good: was a leaking injector!!
Finally, went to a fuel injection specialized shop. The technician opened the hood and after a few minutes inspecting the engine bay told me that one injector wasn't working well, just because the sound of the engine... :D
After removing the injectors, he put them in a test machine. There was one test where all the injectors had to stop to spray, but the number six was still leaking fuel.
Soooo... went to a shop, bought a new injector and the technician replaced it. That's all!! (I'm feeling like a dumb)

I still have some issues with the idle, but I will take the car to another technician who was a Snap On scanner with the GM specific cartridge.

Thank you so much guys! You rock!


88 Beretta V6 2.8 M/T
Weird car in Peru, weird member in Bnet


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