'89 Ranger Blowing Smoke and Burning Gas

[Korey5640]

Hello. I just bought a '89 Ford Ranger XLT 2.9L, with an Auto transmission.

It runs rough and loud(new muffler/exhaust would fix it). But my big problem is that it runs rich while blowing black smoke. We checked spark plugs, all fairly dirty and were replaced, and then checked the air filter just to see how bad it was...it was pure black , basically a clump of dirt and grime. It was removed for now. We started it back up and let idle, still blew smoke fairly bad.

We checked the timing with a timing light, found that it was off. If the timing was fixed, would that help this problem? If not, what else could be the problem? Where else do we go from here to fix this problem? After we replaced the spark plugs and removed the air filter(just so it could get air for now) it idled smoother and did not have as much rattle in the cab but still blows smoke, black smoke.

Please help!

[Psychopete]

It's running rich. Sounds like all plugs had black carbon, so a sensor is in need of replacement. Check the codes in the computer for something obvious.

http://www.troublecodes.net/Ford/

If the codes come up 1..1....1..1, the computer couldn't find any electrical faults. Here's where it gets tough. Wiring diagrams make it easy though. I don't know you're specific wiring because they changed colors throughout the years.

The fuel pressure regulator could be shot. Check for fuel in the vacuum line running from the vacuum splitter to the FPR on the fuel rail. (Driver's side, near firewall) If you have gas in that line, the FPR diaphram is ruptured. Not all bad FPRs go out like that, you'll need a fuel pressure gauge to really determine if you have a fuel pressure problem.

Check the voltage from the o2 sensor. **Though, the o2 normally won't cause an issue until after the truck reaches operating temperature. It won't read until the o2 is heated. (2.9L Rangers have HEGO) Located on the Exhaust y-pipe before the catalytic converter.

I believe there is a table for resistence vs. temperature on the ECT in one of the Hayes or Clilton's manuals. Check this. This sensor will also cause a rich mixture if it's bad. Located on the lower intake manifold, passenger side. It's the engine coolant temperature sensor. Not the gauge sender. The gauge sender has 1 wires, the ECT has 3?

The IAT will also cause a rich mixture if it fails and thinks it's cold outside. (cooler air = closer air molecules = needs more fuel) Located on the passenger side of the upper intake, I believe the middle runner.

Check the voltage at the TPS. If the TPS is giving a higher voltage (should be around .9 at idle, 5.5 at WOT), it will give it more fuel because it thinks it's getting more air. Located on the passenger side of the throttle body.

Lastly, check all of the vacuum lines and pay close attention to the MAP sensor. I converted my Ranger to MAF, and really generally don't have any clues on how to test the actual MAP. Usually located on the firewall, passenger side. Little black box.

There are other factors, but these were the most common that I could think of off hand.

Pete

[Korey5640]

Thanks.

With all this, could the Timing be the problem? It sounds like the timing is off enough so that all fuel is not burt until being released by the truck, therefore buring in the tailpipe, and causing the problem. Could this be?

[Psychopete]

Originally Posted by Korey5640

Thanks.

With all this, could the Timing be the problem? It sounds like the timing is off enough so that all fuel is not burt until being released by the truck, therefore buring in the tailpipe, and causing the problem. Could this be?

Cam timing? I've only heard of 2.9L jumping timing when the engine was turned backwards. Even turning it the wrong direction, chances are it's not going to jump.

What would happen is that the intake valve would open and close at different times affecting the powerband. In extreme cases, your engine would be fried, but if the cam timing were to jump, the effect would probably be pretty extreme.

Ignition timing? Check it if in doubt. Make sure you pull the SPOUT on the injector harness. It's a little square thing. The computer advances and retards the timing, pulling the spout will allow you to check/set the base timing. If it were advanced, it would probably detonate and maybe ping. It sounds like the fuel is burning, just the computer is telling the injectors to stay open for too long because a sensor is giving it a reading that makes it think the truck is running lean, hence the black spark plugs. Definately scan the codes .

Pete

[megamoonie]

Just a question:

If the timing belt was off, wouldn't it misfire? What else can an off timing belt do/cause?

[Korey5640]

Ok, recently we found that it flooded a few times, to the point we went and bought new spark plugs. In the process we found that 2 spark plug wires were now un-usable and cracked beyond repair. Replaced those and now it runs better and has much more pickup to it. However, it now blows White(with some gray tint, mostly white) smoke if I hit the gas enough to jump above 3,500 RPM's very suddenly.

When driving on side streets/at a constant speed it does not smoke, however at idle and sudden acceleration it smokes badly.

Any new ideas?