2.9 will not take the gas

jprevat · Nov 15, 2014

Never had trouble with it until I ran it out of gas the other day. Added five gallons back to it and it drove home no trouble.

Yesterday I go to crank it and I get no fire. The engine just turns and turns. I get it to fire and idle, but if I press the gas it bogs and then acts like it runs out of gas and turns off.

I changed out the fuel filter and now it will take the gas while in park and neutral half the time, but basically it didn't help much.

I cleaned my IAC, PCV, and the contact points on my throttle position sensor.

No change.

I checked my EEC4 codes and popped a 4-1, so I'm running lean. I don't want to just start throwing parts at it.

Any help for the new guy, would be amazing yall.

RonD · Nov 15, 2014

Reads like either the Fuel Pressure Regulator(FPR) on the fuel rail or, the likely issue, the fuel pump is going bad.
Running the tank dry causes fuel pump to overheat, one there is no gas sloshing around to cool the pump and two pump runs at higher speed pumping air until you turn off the key.

I would rent/get a fuel pressure gauge, hook it to the fuel rail.
'89 should show 30-35psi at idle, remove vacuum hose from FPR and it should jump to 40+ psi
If gasoline comes out FPR vacuum connection, replace FPR.
If fuel pressure is lower than 25psi replace pump.

jprevat · Nov 16, 2014

RonD said:
Reads like either the Fuel Pressure Regulator(FPR) on the fuel rail or, the likely issue, the fuel pump is going bad.
Running the tank dry causes fuel pump to overheat, one there is no gas sloshing around to cool the pump and two pump runs at higher speed pumping air until you turn off the key.

I would rent/get a fuel pressure gauge, hook it to the fuel rail.
'89 should show 30-35psi at idle, remove vacuum hose from FPR and it should jump to 40+ psi
If gasoline comes out FPR vacuum connection, replace FPR.
If fuel pressure is lower than 25psi replace pump.

I just picked up a fuel pressure gauge so I will be hooking it up as soon as the rain quits for a minute.

jprevat · Nov 16, 2014

So I hooked up the fpg and I read about 32 psi. at idle and the rain opened back up so I will finish the test on the next break in the rain.

It is taking the gas at idle and even took it in reverse but as soon as I put it in drive and tried to take off it bogged right back out on me.

RonD · Nov 16, 2014

32psi is right where it should be, so pump should be OK.
Since you have the gauge run engine at 2,000 RPMs for 30 seconds make sure pressure holds.
Also, after shutting off engine leave gauge connected, pressure will drop a little, but no more than 8-10psi, and it should then stay there, check it after 5 minutes, if it's the same then system is good, no leaks.

What are the RPMs at cold start, should popup to 1,500+ , then drop to about 1,100 in a few seconds.
This is the computer reading engine temp(ECT sensor) and setting cold engine "target" idle.
As engine warms up idle should keep dropping until it gets to 800, computers "target" idle for automatic transmission vehicles.

After engine is warmed up unplug IAC Valve, RPMs should drop to 500 or engine may even stall, either is fine.
If RPMs stay high then you have a vacuum leak, leave IAC Valve unplugged and start checking.
If RPMs drop then check MAP sensors vacuum line, MAP sensor is usually on the passenger side firewall behind main wiring harness, follow the vacuum line.
Unplug its connector and make sure it is clean and dry, check vacuum line.
MAP(manifold absolute pressure) sensor data lets computer set air/fuel mix, if this is slightly off then you can end up with lean mix and have that loss of power.

jprevat · Nov 16, 2014

RonD said:
32psi is right where it should be, so pump should be OK.
Since you have the gauge run engine at 2,000 RPMs for 30 seconds make sure pressure holds.
Also, after shutting off engine leave gauge connected, pressure will drop a little, but no more than 8-10psi, and it should then stay there, check it after 5 minutes, if it's the same then system is good, no leaks.

What are the RPMs at cold start, should popup to 1,500+ , then drop to about 1,100 in a few seconds.
This is the computer reading engine temp(ECT sensor) and setting cold engine "target" idle.
As engine warms up idle should keep dropping until it gets to 800, computers "target" idle for automatic transmission vehicles.

After engine is warmed up unplug IAC Valve, RPMs should drop to 500 or engine may even stall, either is fine.
If RPMs stay high then you have a vacuum leak, leave IAC Valve unplugged and start checking.
If RPMs drop then check MAP sensors vacuum line, MAP sensor is usually on the passenger side firewall behind main wiring harness, follow the vacuum line.
Unplug its connector and make sure it is clean and dry, check vacuum line.
MAP(manifold absolute pressure) sensor data lets computer set air/fuel mix, if this is slightly off then you can end up with lean mix and have that loss of power.

Ok so here are my findings so far.

I am getting some gas weeping from the rear of the FPR, but it is only drops and from the rear of the FPR itself.

I also noticed that when I hold the pedal at a solid position my RPM's will fluctuate around 150-200 with no added input.

My RPM's do as they are suppose to following the 1500-1100-800 order on start-up.

Unplugging my IAC stalled the engine immediately.

The first time I tried the 30-second test my pressure dropped and my engine died, however the next 3 tests went perfectly and my pressure held steady. I turned the engine off between each test.

5 minutes after I turned the engine off my fuel pressure had dropped maybe 2 PSI.

Oh and the MAP vac line is good.

jprevat · Nov 16, 2014

BTW where does the vacuum line go that is located on the bottom of the 4-way hub on the drivers side of the upper intake? Mine is just hanging loose and I have no idea where it could go.

RonD · Nov 16, 2014

You should have a vacuum hose diagram on the rad support, where the hood latch is, next to fan belt diagram.

Abbreviations are here: http://www.therangerstation.com/tech_library/ford_vacuum_diagram_abbreviations_descriptions.shtml

There is a 1989 2.9l vacuum diagram in this thread: http://www.therangerstation.com/forums/showthread.php?t=146313

That is for a manual trans vehicle, your Automatic will have an extra line that goes to the transmission.

The "4-way hub" is called the Vacuum Manifold on diagrams, or "Man Vac"

That line needs to be plugged in or just plugged because it is an active vacuum if hooked to the vacuum manifold

jprevat · Nov 16, 2014

RonD said:
You should have a vacuum hose diagram on the rad support, where the hood latch is, next to fan belt diagram.

Abbreviations are here: http://www.therangerstation.com/tech_library/ford_vacuum_diagram_abbreviations_descriptions.shtml

There is a 1989 2.9l vacuum diagram in this thread: http://www.therangerstation.com/forums/showthread.php?t=146313

That is for a manual trans vehicle, your Automatic will have an extra line that goes to the transmission.

The "4-way hub" is called the Vacuum Manifold on diagrams, or "Man Vac"

That line needs to be plugged in or just plugged because it is an active vacuum if hooked to the vacuum manifold

Thank you very much. Those are the same schematics I was able to find on here, but I was unsure of my "extra" line. I put a screw in the end of it just because I could not find where it needed to go and I am getting gasoline weeping around the screw.

As far as my running issue would it be a good idea to pick up an FPR and see if that remedies my problem?

RonD · Nov 16, 2014

jprevat said:
Thank you very much. Those are the same schematics I was able to find on here, but I was unsure of my "extra" line. I put a screw in the end of it just because I could not find where it needed to go and I am getting gasoline weeping around the screw.

As far as my running issue would it be a good idea to pick up an FPR and see if that remedies my problem?

FPR should have a vacuum line attached to it, so I bet that vacuum hose goes to FPR, and FPR diaphragm is leaking fuel and it is going down that vacuum line, if it is then yes FPR needs to be replaced.

jprevat · Nov 16, 2014

RonD said:
FPR should have a vacuum line attached to it, so I bet that vacuum hose goes to FPR, and FPR diaphragm is leaking fuel and it is going down that vacuum line, if it is then yes FPR needs to be replaced.

The FPR has a vac line that runs up to the tree that is attached. This unused line is hanging off the low side of the tree so I'm thinking that the FPR is leaking gas into the tree and draining into the unattached line. I will pick up a new FPR tomorrow and update when I see some results.

RonD · Nov 16, 2014

Yes, but just check the FPR vacuum line for fuel, that will tell you.

jprevat · Nov 17, 2014

RonD said:
Yes, but just check the FPR vacuum line for fuel, that will tell you.

I did find a small bit of gas there but what amount would constitute a replacement of the FPR

RonD · Nov 17, 2014

jprevat said:
I did find a small bit of gas there but what amount would constitute a replacement of the FPR

Any gas or even the smell of gas in the FPRs vacuum line would mean "replace it".
Only way for gas to get there is thru cracked FPR diaphragm

jprevat · Nov 18, 2014

RonD said:
Any gas or even the smell of gas in the FPRs vacuum line would mean "replace it".
Only way for gas to get there is thru cracked FPR diaphragm

Then that is at least one of my problems. Thank you very much for helping me out.

Ill chime in again when I have the result.

2.9 will not take the gas

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