240 Drain/replace fluids, hesitation, throttle body Topic is solved

[cgreygoose]

it was an engine speed sensor that was replaced, NOT the engine temp. sensor. it's getting worse, today stalled a few times trying to accelerate from a red light. i had introduced Seafoam per instructions last week and upon changing out the oil & filter this past weekend, the flame shield & pvc hose was full of junked up oil residue but after cleaning those areas still no difference in acceleration.

[cgreygoose]

Bill,

I got it back from the Volvo place where they removed the whole throttle body housing and cleaned it out, new gasket, new adjustments at , TPS, throttle arm linkage & adjusted the accelerator cable where it wraps around the circular disc. I also installed a new speed sensor, and before I replaced the MAF from another volvo,the hoses's were all full of oil again as was the flame shield all gunked up. but still not much difference when trying to accelerate. I put my original MAF back on but forgot to connect it. the car sputtered, almost stalled during idleling but once I put it in drive I was off. felt like a turbo, drove like it should with great pick up, (well way way much better than before), but once I plugged it back in, it was back to slow acceleration.

So, what does that tell you? why plug the MAF back in ? I'm still getting really bad gas mileage for this 4 cylinder. This might be way out in left field but could the transmission be contributing to this slow acceleration? I'm on my 2nd fluid refill/drain and it's come much cleaner since the first draining.

I don't really know what else to do.

thanks,
Aaron

[cgreygoose]

FINALLY WE ARE DONE ON THIS POST. IT TOOK THE 3ED BOSCH MASS AIR SENSOR FOR ALL MY ACCELERATION PROBLEMS TO BE TAKEN CARED OF. MANY THANKS.

AARON

[donlab]

Wow, I just read this complete thread. I am also having this exact problem and replaced everything except the Bosch Mass air sensor. I will try and change this. Thanks for the heads up!

[wojeepster]

Code: Select all

I want you to check the fuel pressure regulator on your car. It serves as a "accelerator pump" when you depress the throttle and since this seems to be where you are having your problem it may be what is wrong. The fuel pressure regulator is located on the fuel rail that feeds the injectors. It will have a hose on it that connects to the intake manifold just after the throttle body. Inspect this hose for cracks and splits replace if necessary. If hose is ok pull end off of fuel pressure regulator and smell end of hose. If you smell gasoline it means the diaphram is ruptured and you need a new fuel pressure regulator. If you have a fuel pressure gage I would check that too but most folks don't have one.

[frances]

Hi Everyone,
I just registered and was hoping the talks between Aaron and Bill from 3/18/11 can go on. I have an 88' 245 Volvo. This weekend I removed the throttle body and all air hoses in order to replace the Oil Separator. In removing the throttle body, I had to detach the Throttle Position Sensor from it's Electrical Lead, it was tight but I got it off, carefully with a flathead. I didn't know the TPS screws actually adjust the sensor, in the process I loosened them as it gave a better angle for the flathead. I managed to replace the flame trap, PCV hose, nipple, Oil Separator and cleaned the throttle body. It was today that I came across Bill and Aaron's posts about the TPS making a click when you go clockwise and than counter clockwise. As I had both screws completely removed from the TPS, I turned the unit back and forth (5) five times unaware that I was disturbing the unit in it's function. I tightened the TPS in no particular way, just so it was tight. Having read all the posts, I want to set the TPS as best as I can. Does the TPS need to be attached to its electrical lead to "click"? and does the key need to be in the ignition turned at I, II, or III? I do little work with electric and all.
Thanks,
Avery