Now that I read the codes I need help.
1991 F150 XLT Lariat 4X4 Truck with 5L motor running bad.
117K + miles
The current owner uses this truck for whenever they need to haul stuff

The truck will start and run BUT it does not take too much gas and on Sat I think I flooded it out because I had to wait 20 mins after it stalled in the back yard.

I been told the plugs and wires have say under 5 K miles on them.
I cleaned the cap and rotor.

Where should I start fixing this truck?
What other info could you use in helping?
Thanks


So the light went out BUT problem continues.
I read the codes and found.

11
11
11
29 Insufficient input from vehicle speed sensor. Would be nice if I fixed it. Speedometer does not work How hard to fix?

33 EGR valve opening not detected. I wonder if valve bad or sensor?

41<table table="" style="font-size: 100%;" border="1" cellpadding="2" cellspacing="0"><tbody><tr><td>HEGO sensor circuit indicates system lean (right side).</td> </tr> <tr> <td>
</td> <td>
</td> <td><center>X</center></td> <td>No HEGO switching detected always lean (right side).</td></tr></tbody></table>what is this?

51
Engine Coolant Temperature Sensor (ECT)

ECT sensor signal is greater than the Self-Test maximum of 4.6 volts. ECT sensor.

87
<table table="" style="font-size: 100%;" border="1" cellpadding="2" cellspacing="0"><tbody><tr><td>Fuel pump primary circuit failure. When the FP relay was activated by the EEC, voltage was not detected on the control circuit.</td> </tr> <tr> <td>
</td> <td><center>X</center></td> <td>
</td> <td>Voltage was not detected on Fuel Pump Monitor while the engine was running.</td></tr></tbody></table>Oh this could be bad ?

96
Fuel pump secondary circuit failure. The EEC did not sense battery voltage on the Fuel Pump Monitor circuit.


I will close this post and open new
Thanks

 

Check fuel pressure at the rail it should be about 40psi with vacuum removed from the regulator. The other items flagged by the codes won't have much effect on engine operation.

 

Is this the coolant temp sensor?
I removed the wire.
Checked at 70 outside cold motor no resistance.
Ran motor for like 5 mins and temp gauge started to move and still no resistance.
Using this site for checking http://fordfuelinjection.com/?p=28

<table style="width:auto;"><tr><td><a href="http://picasaweb.google.com/lh/photo/NqwHqT4J0h65ODY-ypNIBw?feat=embedwebsite"><img src="http://lh4.ggpht.com/_W2tJw7DhtBY/S94ZP2uOJZI/AAAAAAAAA7s/k5XnIJzI30w/s144/P1090016.JPG" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/Ken2400/Free?feat=embedwebsite">free</a></td></tr></table>

Thanks

 

It get better. I went to check flue filter. It was not mounted to the frame. Two mins later I mounted it. Unknown who has been working on this truck. It looks rusted BUT I live in rust belt central NY State.

Did not see vac line just red wire to top of what maybe regulator.
I do see what looks like new flue line to it. So I need to ask owner if they had flue line fixed in the last few years.

I did see black plastic cap on what looks to be connector coming off the top of the rail.

So can be checked with just turn off key and not starting truck?

Or should truck be running to get good reading.
Fuel Injection Pump Tester

Harborfreight has one. I need to see someone I know has one. I think it would be 5 min job to check?

 

As for code 29, speed sensor, I went under and I was able to just pull the cable right off. Something tells me I should not been able to do this without removing bolt.
Need to look at it again.

Thanks

 

I replaced the coolant sensor with one from a 1990 F150 5.8 L motor. It fit.

Clearing codes now by disconnecting battery for 1/2 hour.

Thanks

 

I found a plastic vac can from a 94 F250. It made the truck run a little better BUT other things still need fixing. Still no vac at the EGR valve.

 

I have 28 without changing the vac to the regulator.

 

I have 28-30 PSI. I changed the fuel BUT that did not make much difference.
Truck overall runs better than when I first got it BUT still does not like to take too much gas.

Thanks

 

The owner had the truck looked at and it turned out to be

A BAD coil.

I did not look at the coil, cap, rotor, plugs and wire because she said she had the plugs changed and the wires looked good.
Oh well should have left no stone unturned.

They are having something else done but the could not remember.
Hope to report back once I find out.