Off idle engine bog
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Off idle engine bog
My '93 f-150 5.0 has recently developed a engine bog while accelerating off idle and when shifting gears. If it were a carburetted engine I would suspect the accelerator pump but this is efi. Could it possibly be the throttle position sensor? If it were not set up properly the throttle valve would open before the tps sends a signal for more fuel. If this is the case, what is the method for setting the tps? Are there any othr suggestions. It does this whether it is warm or cold. I also have to clean the idle control bypass valve too as tthe cold idle is a bit erratic, wants to stall at the first stop unless I warm it up for a while. Thanks for any help you can give me. SR.
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From: Vestal USA
Off idle engine bog
You might want to check your EGR relay. Try uplugging the Green vacuum hose to the valve and see if it goes away. The relay is about $35. It worked for me when I had similar symptoms.
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Off idle engine bog
HI. I have had my egr blocked off for about 8 months now with no side affects at all . This is something that just started 2 weeks ago. I havn't had time to clean my idle air controll yet but will this weekend. The symptoms mimmick a lean condition just off idle, a real bog then accleleration. I will also have alook at the throttle valve and tps when I clean the iac. Could it be possible that the first section of the tps rheostat could be worn out as this is where the position would be used the most in normal driving? There may also be a delay in the time that the throttle starts to open and when the rheostat actually starts to move causing a delay in the signal to the computor. I a not sure what the proceedure is for checking and setting this up. Any suggestions? SR.
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Off idle engine bog
I am also having the same symptoms on mine ('92 F150 5.0 w/manual). I had been having the EGR related missing at ~30-35 MPH, so I blocked my EGR (installed thin metal plate with 1/8 inch hole drilled in center). I had previously replaced both in-tank pumps (front & rear) to replace flow problems with them (rear had no pressure--front was heat sensitive).
On the front tank, occasionaly (at traffic lights, stop signs, etc.) the idle will become rough and will have no power when the throttle is pressed. The engine seems to be starving for gas---however if I'm moving (above 20 MPH) switching to the front tank causes no hesitation or stalling. When the engine is having the problem at idle and is about to stall completely, immediately switching to the rear tank corrects the "bogging" / stalling problem. Is there a pressure gauge that can be installed on the injector fuel feed so I can monitor the pressure? Is the problem related to the tank selector switch? Is there an idle adjustment?
Thanks in advance
Gembeau
On the front tank, occasionaly (at traffic lights, stop signs, etc.) the idle will become rough and will have no power when the throttle is pressed. The engine seems to be starving for gas---however if I'm moving (above 20 MPH) switching to the front tank causes no hesitation or stalling. When the engine is having the problem at idle and is about to stall completely, immediately switching to the rear tank corrects the "bogging" / stalling problem. Is there a pressure gauge that can be installed on the injector fuel feed so I can monitor the pressure? Is the problem related to the tank selector switch? Is there an idle adjustment?
Thanks in advance
Gembeau
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Off idle engine bog
There is no idle speed ajustment, it is done by the computor. Most idle problems stem from a carbon buildup in the idle control valve. How this stuff gets there is beyond me but it does and it gets onto the throttle buterfly as well. Cleaning these with carb cleaner usually solves this problem. I haven't had time to do mine yet, maybe today.... anyway, your switching tanks to solve the stumble doesn't work for me, i've tried it. I think my problem may have started with the use of an in tank fuel injector cleaner so perhaps my fuel filter is plugged although it is only a year old now. I just have to get my lazy ##### off the couch and get to it but now winter has returned and it is bloody cold out again and I don't have a heated shop, just the great outdoors so the couch and fireplace are awfully inviting and besides, there is a Dallas Cowboys cheerleader calender thingy on tv and that really warms me up.....
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