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Discussion Starter #1
My father in law has a 1989 f150 351w and it does not run very often. He went to crank it up and it sputtered and ran very bad. He thought it was the cap and rotor, so he replaced them. Now it will not fire up or even try to start. New plugs and wires are next, but I don't see how all of them would have gone bad at the same time. I checked all the obvious stuff like firing order and the timing and it looks good. The fuel rail has good pressure and all fuses are good. All connections look good. Spark looks a little weak. This ignition has the module on the dizzy and all the Haynes manual checks come out good. I ran the codes and it shows a #53, TP sensor out of range. If this is bad could it keep the fuel from injecting? I doubt it, but figured it was worth a try.

thanks
stephen [/quote]
 

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Hello

First you need to find out what the resistance should be set at. Then hook up your multimeter to the pins going to the throttle position sensor and loosen the adjustment screws. Pivot the sensor on its mount until you get the required resistence. Pretty easy.

Hope this helps.

Tom
 

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Hey dude check out this info on this link its really helpful putting a code scanner is not the same as running a self test BTW I know,

http://sbftech.com/index.php/topic,2471.0.html

This is a page how to read the codes and run engine self tests.

http://sbftech.com/index.php/topic,1031.0.html

That is a page on the base idle reset to hopefully get it back where it should be.


Here is my latest post, read the response should tell you how to read is the TPS is bad, but first try the base idle reset first then go from there.

http://sbftech.com/index.php/topic,17168.0.html


If ya got any more questions ask me I am happy to help


Also TPS being set wrong should not effect spark or injectors, as far as weak spark maybe its a coil, they can be expensive on these cars, I went to a junkyard ford ran the same coil on 3.0 and the 3.8 in the taurus and the 3.0 and 5.0 mustangs and 5.0 5.8 and 460 trucks its all the same some are mounted differently but they all work well with each other if the coil is suspect try using another one.


Good luck
 

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Discussion Starter #4
Re: Hello

747JETMECH said:
First you need to find out what the resistance should be set at. Then hook up your multimeter to the pins going to the throttle position sensor and loosen the adjustment screws. Pivot the sensor on its mount until you get the required resistence. Pretty easy.

Hope this helps.

Tom
I understand that I can adjust it, but I ran out of time today. I was just wondering if it is giving a bad readiung would it keep fuel from being delivered to the cylinder?
 

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Discussion Starter #5
dbu8554 said:
Hey dude check out this info on this link its really helpful putting a code scanner is not the same as running a self test BTW I know,

http://sbftech.com/index.php/topic,2471.0.html

This is a page how to read the codes and run engine self tests.

http://sbftech.com/index.php/topic,1031.0.html

That is a page on the base idle reset to hopefully get it back where it should be.


Here is my latest post, read the response should tell you how to read is the TPS is bad, but first try the base idle reset first then go from there.

http://sbftech.com/index.php/topic,17168.0.html


If ya got any more questions ask me I am happy to help


Also TPS being set wrong should not effect spark or injectors, as far as weak spark maybe its a coil, they can be expensive on these cars, I went to a junkyard ford ran the same coil on 3.0 and the 3.8 in the taurus and the 3.0 and 5.0 mustangs and 5.0 5.8 and 460 trucks its all the same some are mounted differently but they all work well with each other if the coil is suspect try using another one.


Good luck
The first sites are a lot better than my Haynes manual, but I got the codes already. I have already replaced the coil, rotor and cap. You say the TPS should not affect the fuel, and thats what I suspected. It must be something else.

thanks for all ya'lls help

stephen
 

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skosler said:
You say the TPS should not affect the fuel...

stephen
Unless the TPS were to have failed to a high voltage reading, which is the same as holding the throttle wide open, and is a signal to the computer to go into the "Clear Flood Mode" , which shuts off the injectors. So there is a possablity that the TPS could cause it to not start.

Earl

(Edit) I just checked a buddy's Ford service manual and a code 53 is high TPS voltage ( above 4.84 v) so there is a possability that it could be the cause
 

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Discussion Starter #7
PearsonFan said:
(Edit) I just checked a buddy's Ford service manual and a code 53 is high TPS voltage ( above 4.84 v) so there is a possability that it could be the cause
hmmmmm?

I will check this tomorrow. I guess I could just unplug the sensor and it should fail to a 'safe' position, right?
 

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My '94 F250 with 351 did that last winter. Wouldn't start and I dug through the ignition and fuel delivery for an hour before testing the TPS sensor. It was reading like it was at almost full throttle all the time. It was almost impossible to start and when it would start it would rev up and then cut down and then rev up again. The sensor isn't adjustable (clock-able), it just needs the throttle body removed to get to it. It's not a bad job though, takes about a half hour with basic hand tools. I think the wires to test for voltage are the orange and green ones, but I don't remember for certain. Anyway, there's 3 wires and it's pretty easy to figure out which ones to poke with the meter leads.
 
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