I have an intermittent (it has happened twice: once in Feb, once today) problem with my 2006 Ford Ranger. Sometimes, when I start the car, the engine idles erratically, black smoke pours out of the engine and there is very little power when I push the gas. Last time this happened I struggled with it to the Ford dealer for fear that turning the car off would kill it and I’d have to tow so I can’t be sure that this happened both times, but this time I pulled over and opened the hood to hear a ticking sound coming from near the distributor cap. I took a video to try to figure it out, but it’s not very good, it’s on youtube here: http://www…pISrcWQRw. The problem stops as soon as I shut the car off and restart it. I have an extended warranty and I took it in to the dealer last time these are their remarks on the invoice:
TEST EEC NO CODES. PIN POINT TEST, TEST IGN SYSTEM, FOUND GOOD SPARK ON ALL CYLINDERS. ROAD TEST WITH IDS RECORDER MONITOR. FOUND ERRATIC MAF SENSOR. HAS SIGNAL SPIKES, NOISY SIGNAL. FOUND AIR CLEAN LID SECURED PROPERLY. AIR FILTER CLEAN. REPL. MAF SENSOR AND RETEST, PASS ROAD TEST VEHICLE OPERATED PROPERLY.
They replaced the mass airflow sensor assembly but were not able to reproduce the black smoke and other problems, so I think that that may have been something else that was weird and not related.
Any advice, I don’t want to take it back to the dealer without knowing something about the problem… last time that didn’t fix it.
Black smoke is an indicator of a fuel problem. Intermittent problems are the worst to try and fix. 2 problems in the last 6 months I would try to understand how to replicate problem so you can stop by in failure mode to get it fixed. The ticking may be due to too much gas washing out the oil, so if I had to guess it would be a failing injector. Try some sea foam every now and then or get it fixed in failure mode.
Sorry, I meant black smoke comes out of the tail-pipe, not sure why I wrote engine…, does that make a difference?
No, I knew what you meant.
At least Youtube clarified something. Your truck doesn’t have a distributor cap.
A misfire in the secondary ignition can cause a symptom similar to too much fuel and can explain the ticking sound; which could be a spark jumping.
This can even happen on an erratic basis.
How old are the spark plugs and plug wires? The former can cause problems with the latter, and even into the coil pack.
I’ve never replaced either, platinum plugs are supposed to last 100K miles, right?
The MAF sensor provides a major input to the Engine Control Module for its fuel injection amount calculation. So if the MAF sensor is intermittant that could have been the problem for the excess fuel and black smoke. There are other sensors that can cause the ECM to command excess fuel. Those would be the Throttle Position Sensor, the Engine Coolant Temperature Sensor, and the oxygen sensors.
It would be great to have the problem present at the repair shop so they can put the scanner on the truck and view the streaming data to see what is out of tolerance. The shop you are using appears to be capable but they are working on the truck when it is operating satisfactorily. Troubleshooting an intermittant is always a ‘tough dog’.
Good luck on this.
Yes, a Mass Airflow Sensor can definitely cause your symptoms, as explained by researcher. The black smoke is carbon, and that and the erratic idle were caused by the engine trying to run too rich. Too much fuel + too little oxygen = black smoke and erratic idle. The MAF sensor is a key input to the computer that determines how much fuel is fed in.
Honestly, it sounds to me like you’ve found a shop stocked with real diagnosticians and not just part-changers. This is a good thing. They took the correct steps and did the job right.
It’s normal to be uneasy about car repairs. But in this case I believe your fears are unfounded. Sleep soundly. Your problem has been properly corrected.
mb, I think you are being too hard on the shop. The report the OP presented was in top notch form and the tech justified what he did and did not do anything he could not justify. The people that review the extended warranty claims look very carefully for justification for the direction the tech takes. Now the OP certainly is free to ditch her extended warranty and let a garage that does not have an auditor looking over their shoulder take over.
Justification was provided for MAF sensor replacement.
Good thought OK, If it fails at night, open up the hood listen and look for a stray spark! The poor running condition may shorten the suggested plug change interval.
Huh?
My post supported the shop. I credited them with being diagnosticians rather than just part changers. I said they took the correct steps and did the right thing. I supported their having changed the MAF sensor. I said nothing but good things about them.
Wha?
My error, skimming posts got me there, I read it , you should find a shop, not, you have found a shop, sorry.
In theory, yes. In practice, seldom do any spark plugs fire as well at 100k miles as they do at 30k and I consider the 100k miles practice ill-advised.
Spark plugs can degrade over time and the vehicle owner becomes acclimated to a gradual loss of performance, much like being unable to notice a loss of ride quality due to failing shocks or struts. It creeps up on you gradually.
There’s also the issue of leaving plugs in for that long of a period and having the threads seize; especially true with aluminum cylinder heads where steel and aluminum do not always co-exist very well. When the plugs are removed they will sometimes bring the threads with them and this means spark plug hole repair with Heli-Coils, etc.
Something I should have added. Many of the old air cooled VWs used resistors on the plug wires and when one of these resistors would fail it often lead to poor running, black smoke, and believe it or not; gasoline diluted engine oil.
One would automatically think that engine oil that smells like pure gasoline, ignites readily, etc. would point to a fuel system fault but that was not always the case. It was the ignition.
No problem. We can use it for an excuse for a “beer summit”.