Fuel Line Component - What is it?

[swingjunkie]

Ron,
Test drive today. With timing corrected and fuel pressure improved the engine idles much smoothly. It will hold highway speed without losing power. The engine still lacks power and there is a hesitation when I kick the accelerator. It also develops a noticeable miss after dropping into passing gear. I tried the Clear Flooded Engine Test after the test drive. That was a FAIL. I also let the beast sit and idle a few minutes. It sounded smooth but after 2-3 minutes the engine idled up then down, then leveled out, then idled up and back down to a stall. I can try the test you suggest to locate the leaking injector. Is this the next best step given results so far?

 

[swingjunkie]

Tom,

On the fuel filter replacement I did not find any water, dirt, or debri. The filter looked good, but I figured it to be 29 years old and ready for a change.

I understand your comments on pressure and volume. I did find a spec in the Clymer Ford Ranger and Bronco II 83-87 Shop Manual. It says the fuel pump should deliver 5.6 ounces of fuel in 10 seconds, which would be 33.6 ounces (just over a quart) per minute. I'd like to find one other solid reference on what the expected rate is before atttempting that test.

On current MPG I can't really say. I've driven it less than 100 miles since buying it. I've just been going through it a bit at a time in the evenings, inspecting, checking, tweaking. Visually the fuel gauge seems to be dropping pretty quickly for that little bit of driving so far. Mechanically the things checks out well; it's a solid truck. I just don't feel good enough about the engine performance yet to take it for a long drive.

Thanks for your response and ideas.
Carl

 

[RonD]

Did the engine start on the clear flooded engine test or just fire intermittently?
If intermittently then yes proceed to wet spark plug test.

If it started then throttle cable could be stretched and not opening TPS(throttle position sensor) all the way, so injectors were not turned off, clear flooded engine test was never started.
Have someone press gas pedal to the floor, then try to manually open throttle more at the engine end of cable, if it opens more you need to do the "ranger throttle cable mod", google it.

 

[swingjunkie]

Ron,
The engine started right up. Nothing intermittent about it. I wanted to make sure I had the sequence right, engine OFF, key ON, accelerator to the FLOOR, CRANK the engine. So I warmed it up again and repeated it. Same result, it fired right up. I also had my wife push the accelerator to the floor and tested for further play in the throttle cable. NONE found. It was tight. It seems the Clear Flooded Engine Test never started as you suggest?

This machine is a smoker, and I was surprised to see how much water and carbon were blown out of the exhaust on start up. I don't know if this is another clue as to the engines issues.

Your comment on the TPS made me look into this, and I found yet another new piece had been installed by the previous owner(Yes I am still locating all the componnets as I go thru this engine). The TPS is new.

So the previous owner attempted resuscitation of this truck, replacing the TPS, the high pressure fuel pump, the fuel pressure regulator, the O2 sensor, the plugs, the air and oil filter, and all fluids(coolant, oil, transmission fluid). I think they gave up.

To date I have changed the fuel filter, removed the mystery filter which originated this post, changed the muffler and tail pipe, adjusted the timing.

Not sure where this leaves me, but thanks for your response and suggestions. I am wondering if the catalytic converter could be causing all this mayhem. It looks to be original to the truck.

 

[tomw]

The TPS in the old Rangers needed adjustment when installed. I do not remember the procedure, but if it is not adjusted, it might not sense WOT. OTOH, I don't remember that procedure being in the manual. I am not saying it isn't, but I don't remember it.
As far as the idle getting wobbly, that can be caused by a MAP sensor that is going south. It adjusts the fuel mix (injector 'on' time) based on manifold vacuum which is an indicator of the load on the engine. WOT would give very little vacuum, so the injectors would be 'on' longer. That is WOT with the engine running, not stopped or starting up. Closed throttle at idle would produce higher vacuum, and the injectors would be cycled shorter as the load is way down. I do not remember what happens if you disconnect the MAP, but a bad one will make the idle WAAaaaaay goofy. The MAP is a box with a vacuum line to the manifold and several wires connected. Three, I think, ground, 5V reference and signal. It produces a varying Hz 'buzz' to the computer. If you know the local barometric pressure, there is a table you can lookup the Hz(frequency) to check its accuracy. Some DVOMs have a Hz selection, and can display the Hz.
tom

 

[swingjunkie]

Thanks for the heads up on the TPS sensor adjustment. I found a short video describing the adjustment precedure. It says the voltage range should be .75 - .98 volts. KOEO. Mine was at .749. I adjusted it to the middle of the range .87 Volts. It seems to have helped.

The MAP sensor solenoid is engaging when I hit the accelerator. It has a loud audible click. Whether it's doing it's job properly I can't say.

I did remove and clean the IAC. It seems to be working OK. My only evidence of this is that unplugging it while the engine is idling causes the engine to stall.

I also changed out the plug wires, even though I thought they were good, and that made a significant change. Guess one of them was on the way out.

Thanks for your advice
Carl

 

[tomw]

I do not know of any MAP sensor solenoid. The '85 with EFI, CA emissions, has two solenoids under the plastic cover to the rear of the battery. They do the EGR move and hold functions. The MAP has a simple hose connection to manifold vacuum, and I think 3 wires from the harness. About the size of a deck of cards, with wire & vacuum line. Only thing under the hood like that. I thought under the same plastic cover, bolted to the inner side of the fender, rearmost under the mentioned cover, hose & leads on the bottom.
It does not click. Totally silent. I can send a picture of the gizzards if I knew how to post one.

tom