I need help.... 1984 Chevy silver ado

[littleherc]

Well as the title says i need some help... the choke light is staying on... When i unplug the choke from the engine it turns off... I changed out the oil pressure sensor and now the gauge reads 0 and does not go up.... Could this all be from a fuse? or should i changed the oil pressure gauge? All and any help would be great...

 

[chengny]

I am not too familiar with 305's. So let me ask this first;

Does what you have behind the distributor look like this?

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If so, note the text.

The bell shaped sensor is an oil pressure sender and is only used to supply a signal that the dash gauge uses to move it's needle. It has no connection to the choke light.

The other sensor (the one with two prongs) is a pressure switch. It closes when the oil pressure reaches around 10 psi. It can have one or two functions. One thing it does is supply power to the electric coil within the choke heater (this causes the choke to begin opening almost immediately after the engine is started). It's other function is to cause the LOW OIL PRESSURE warning light to illuminate if the engine oil pressure falls below 10 psi.

If you have factory gauges, I think we can assume that you do not have that "idiot light" - to indicate low oil pressure.


When i unplug the choke from the engine it turns off...
This is normal. The CHOKE light is grounded through the body of the choke heater casing. Unplugging it will break the circuit and extinguish the CHOKE light.

the choke light is staying on... & I changed out the oil pressure sensor and now the gauge reads 0 and does not go up....

If you are certain that you have oil pressure and the CHOKE light is lit, it would probably indicate a bad switch - not a bad sender. Unfortunately it sounds like you changed the sender - which as noted above - only drives the oil pressure gauge.


Try a new oil pressure switch and see if the CHOKE light goes out when the engine is started and oil pressure is established.

As to why the dash oil pressure gauge suddenly stopped working after you changed the sender - that's anyone's guess. Double check your wiring connection and look for a broken lead to the sender.

 

[littleherc]

First and foremost i would like to thank you for the reply.. It does not look like that.... My trucks sender hooks up directly to the engine... Where would the switch be located? Again thank you again..

 

[chengny]

Look down above the oil filter. Older 350's often had the pressure switch screwed into a 1/4" NPT bore shown in the image below - maybe 305's did as well:

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Just be aware, the sender has only one lead connected to it. The switch has three leads (in the example shown above it appears that there are only two leads but two of the three are spliced together inside the plug casing):

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If your switch is down there, it might look like this:

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[littleherc]

Yes sir it is right there by the oil filter.. I will switch out tomorrow.. Sorry I'm a newbie at all this stuff and thank you all for your help!.. Will all the oil fall out when i remove the part? should i drain the oil first...

 

[chengny]

No, hardly any oil will be above the switch - just unscrew it. The only oil that might drain out is indicated by the yellow tracings (maybe a couple of tablespoons - everything else will have drained back down into the sump).

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[adamj]

Yes sir it is right there by the oil filter.. I will switch out tomorrow.. Sorry I'm a newbie at all this stuff and thank you all for your help!.. Will all the oil fall out when i remove the part? should i drain the oil first...

Hey Littleherc, I am curious if you were successful in swapping out the sender? I am trying the same thing, but can't get my hand in a good spot to unscrew the old one... Let me know if you have any tricks for doing this.

 

[littleherc]

Hey Littleherc, I am curious if you were successful in swapping out the sender? I am trying the same thing, but can't get my hand in a good spot to unscrew the old one... Let me know if you have any tricks for doing this.

I basically went head first from the top of the engine and used a socket wrench.. its not comfortable but it worked... do you have the new sender? thats how i found out what size socket i needed...