Oil level sensor bypass

[MrSteff]

I believe i have a bad oil level sensor on my 88 2.9l. It is causing a no start the oil pressure switch has been replaced and the pan is full. Any help would be great

 

[rusty ol ranger]

You sure thats whats causing it?

Mines just got the wires cut.

 

[adsm08]

I believe i have a bad oil level sensor on my 88 2.9l. It is causing a no start

You are wrong. Chevy used to do that kind of stuff, but Ford never did, at least not on the 2.9.

 

[rusty ol ranger]

There is an oil level sensor on the 2.9. It just wont kill the engine. All it does to my knowledge is trip the little check oil light.

Ive never ran one low enough to know though.

 

[Mac]

Just a level indicator, nothing more. Looks elsewhere for problem.

 

[MrSteff]

hmm well it wont let the fuel pump turn on, there is power to the relay the side going to the computer will not prime the pump. My theory was the computer wasnt letting the engine start because of info the sensor's where giving it. The oil light is on so makes a little sense to me, furthermore I did a little googling and it is common in other vehicles have not found anything on a Ranger. I understand i may not be able to wiring around it depending how the sensor talk the the computer. Is there anyway to test it though? I have gone threw all of the fuel system and checked to make sure wires where solid where i am missing the power i am covinced it is a sensor issuse as for which on i do not know. Are you sure the level sensor would not result in a no start?

 

[rusty ol ranger]

Yes. The level sensor wont cause a no start.

So you got power to the relay but the pump isnt running?

The computer is what pops the relay off.

You got a bad relay or bad pump.

 

[adsm08]

hmm well it wont let the fuel pump turn on, there is power to the relay the side going to the computer will not prime the pump. My theory was the computer wasnt letting the engine start because of info the sensor's where giving it. The oil light is on so makes a little sense to me, furthermore I did a little googling and it is common in other vehicles have not found anything on a Ranger. I understand i may not be able to wiring around it depending how the sensor talk the the computer. Is there anyway to test it though? I have gone threw all of the fuel system and checked to make sure wires where solid where i am missing the power i am covinced it is a sensor issuse as for which on i do not know. Are you sure the level sensor would not result in a no start?

The oil level sensor will not cause a no start. It just drops a float and grounds the oil light when you are a quart low.

There are actually no sensors involved in fuel pump priming at all on that truck.

In the passenger foot well, pull the carpet up at the firewall, you will find the inertial shutoff switch for the fuel pump.

Use a test light to check for power on the green wire when the key is first turned on. You may need a helper as it will only last a few seconds.

If you have power there jump power onto the pink wire and listen for the fuel pumps to run.

If both of those tests give you a positive result punch the inertia switch a few times and then push down on the little button oon the top.

 

[MrSteff]

No, I have already checked the inertia switch, but of course, I don't have any power to anything after the relay, I know the relay is good as well. like Ol Rusty ranger said the computer is what pops the relay off, I am not getting this at the relay. My ECU is not telling the pump to turn on.

 

[MrSteff]

would the oil pressure sensor cause a no start? I suppose I should be going through my wires making sure they are intact, The oil light may have nothing to do with the no start but no the less it is still on something is wrong with that system

 

[Curious Hound]

Everybody is telling you the oil level sensor will NOT cause a no start in a Ranger. You have something else wrong. Time to look at the wiring diagrams.

 

[adsm08]

No, I have already checked the inertia switch, but of course, I don't have any power to anything after the relay, I know the relay is good as well. like Ol Rusty ranger said the computer is what pops the relay off, I am not getting this at the relay. My ECU is not telling the pump to turn on.

So if you jumper across the relay the pumps run?

In that case I'd check that the line between the relay and the computer is intact, and if so, the computer is probably the issue.

would the oil pressure sensor cause a no start? I suppose I should be going through my wires making sure they are intact, The oil light may have nothing to do with the no start but no the less it is still on something is wrong with that system

Ford did not involve their oil level or pressure sensors in the fuel circuit at all. Even if they did, you couldn't have it interfere with the fuel pump priming because there is no oil pressure when the engine isn't cranking or running. You have said you aren't getting a priming. Oil pressure issues won't cause a no start on a Ford. Period.


Now, are you sure that the light isn't on because the engine isn't running and so there is no oil pressure?

 

[rusty ol ranger]

No, I have already checked the inertia switch, but of course, I don't have any power to anything after the relay, I know the relay is good as well. like Ol Rusty ranger said the computer is what pops the relay off, I am not getting this at the relay. My ECU is not telling the pump to turn on.

I had this same issue on rusty #1 back years ago.

I ended up basically hotwireing the fuel pump off the key switch.

I do not reccomend you do this.

It wasnt untill recently when i harvested the ECM out of rusty #1 to put in rusty #2 to try and solve other issues.

I got the EXACT same issue with rusty #1s ecm when installed in rusty #2.

So i pulled codes (which i suggest you do).

I dont remember the number, or exact description of the code that came out, but it more less was an internal ECM fault on the fuel pump circuit.

But let me reittrate....

The oil level sensor IS NOT causeing the fuel pump not to run.