2.3L ('83-'97) No Start Unless Gas Pedal Floored

[RonD]

I do that every morning to start my HIGH MILE 1994 4.0l engine, 400+K
I crank it with foot to the floor to pump oil through the engine FIRST, then let off the gas pedal so it starts, wet with oil, no DRY starts, lol

 

[LIMA BEAN]

I would go FPR first. You know some of those 91's had an accumulater/resevoir after the filter and I believe we have it in a tech section from many years ago. They say straight on them "Do Not Twist Off" of sorts . OEM Fuel Reservoir Accumulator for Ford E150 E250 F150 F250 Ranger Bronco | eBay

 

[LIMA BEAN]

Back then there was a rash of this mystery, the bowl doe's have a filter/screen inside it that is not accessible. I believe I and other old timer TRS guys came up with a part # that did have a removable bowl, hell even getting the part was cool so folks didn't have to cut fuel lines.

 

[Reece’sPieces]

I do that every morning to start my HIGH MILE 1994 4.0l engine, 400+K
I crank it with foot to the floor to pump oil through the engine FIRST, then let off the gas pedal so it starts, wet with oil, no DRY starts, lol

Okay this is weird. So I tried cycling the key on and off three times, and then holding down the gas pedal before turning the key, and I continued to hold it down while trying to start it. So the fuel injectors should have been off and it would have started if fuel had been leaking into the cylinders. But the engine just cranked and wouldn't start. I then tried to just start it normally and it did the same thing, it wouldn't start. So then I turned the key, let it crank for a second or two and then pushed down on the gas and it started. So the only way I can start the truck is if I let it crank for a few seconds normally and then put the truck into clear flooded engine mode while it's cranking.

I think fuel isn't leaking per say, but the injectors might be putting in too rich a fuel mixture for it to start on its own.

 

[Reece’sPieces]

Back then there was a rash of this mystery, the bowl doe's have a filter/screen inside it that is not accessible. I believe I and other old timer TRS guys came up with a part # that did have a removable bowl, hell even getting the part was cool so folks didn't have to cut fuel lines.

I'm pretty sure my truck doesn't have the accumulator. It's the 2.3l and it only has one fuel pump, which is inside the tank. Do you think it's the FPR that's gone bad?

 

[Bgunner]

When you say you put your foot on the throttle what exactly do you mean?

Are you putting it to the floor or maybe half way open?

 

[Dirtman]

The computer doesn't actually know the position of the gas pedal. The throttle position sensor does. So my best guess would be your TPS sensor is out of range or faulty and giving the computer false information.

 

[Reece’sPieces]

When you say you put your foot on the throttle what exactly do you mean?

Are you putting it to the floor or maybe half way open?

putting it to the floor

 

[Reece’sPieces]

The computer doesn't actually know the position of the gas pedal. The throttle position sensor does. So my best guess would be your TPS sensor is out of range or faulty and giving the computer false information.

I did pull the engine codes and didn't get one for the tps.

 

[Bgunner]

The TPS can go bad and not throw a code and why I mentioned using a multimeter to test it.

RonD gave the voltages the sensor will read at closed and wide open throttle but in between make sure the voltage goes up linearly and smooth. If there is a dead spot in it the voltage will drop till you get past that point and start to climb again. If the voltage is off at fully closed then it may give you the problems you are seeing.

 

[Reece’sPieces]

The TPS can go bad and not throw a code and why I mentioned using a multimeter to test it.

RonD gave the voltages the sensor will read at closed and wide open throttle but in between make sure the voltage goes up linearly and smooth. If there is a dead spot in it the voltage will drop till you get past that point and start to climb again. If the voltage is off at fully closed then it may give you the problems you are seeing.

okay thanks, I'll test that next with a multimeter to see if it's working.

 

[Reece’sPieces]

Oka

The TPS can go bad and not throw a code and why I mentioned using a multimeter to test it.

RonD gave the voltages the sensor will read at closed and wide open throttle but in between make sure the voltage goes up linearly and smooth. If there is a dead spot in it the voltage will drop till you get past that point and start to climb again. If the voltage is off at fully closed then it may give you the problems you are seeing.

Okay so I tested the TPS. I got around 0.8V with the throttle closed, and 4.6V with it open, and it’s getting about 5V of power. And the ground wire is showing 0 volts. It seems like it’s working fine.

 

[Bgunner]

As you opened it slowly did you notice any drops in voltage? It will be a very fine spot that it would do it if it has a dead spot so opening it slowly is the key here.

If it tests good then I would test the air flow meter to insure that is good as you need 3 things for fire, air, fuel and spark.

 

[Reece’sPieces]

As you opened it slowly did you notice any drops in voltage? It will be a very fine spot that it would do it if it has a dead spot so opening it slowly is the key here.

If it tests good then I would test the air flow meter to insure that is good as you need 3 things for fire, air, fuel and spark.

Okay,
I’ll have someone help me with the throttle to check for dead spots. I just checked my fuel pressure again with the key on and it’s about 38psi which is a little bit low.

 

[Reece’sPieces]

As you opened it slowly did you notice any drops in voltage? It will be a very fine spot that it would do it if it has a dead spot so opening it slowly is the key here.

If it tests good then I would test the air flow meter to insure that is good as you need 3 things for fire, air, fuel and spark.

Just checked the tps again slowly. No dead spots. Any chance this could be a timing issue? Should I check the MAS next?