Running rich, bad fuel injectors?
- Thread starter DW5.0L
- Start date
-
Sponsors (?)
I hook the gauge line up to the black vacuum tree on the fire wall. Its just too low at idle. Not sure why. I replaced all of the vacuum hoses and plugged unused ports, not sure what could be leaking but somethings is obviously wrong.
Yeah, the sound compression numbers were the one bright spot of the day. The car seems to idle and run like it has a stuck choke, its rich and lots of exhaust smoke.
My friend says I should just go with a carb/intake kit and forget about it. I want to keep the FI set up however and its all brand new.
Yeah, the sound compression numbers were the one bright spot of the day. The car seems to idle and run like it has a stuck choke, its rich and lots of exhaust smoke.
My friend says I should just go with a carb/intake kit and forget about it. I want to keep the FI set up however and its all brand new.
In regard to vac readings, your WOT reading should be almost zero. Your idle setting should be near as high as it ever gets (sans unusual situations like decelerating from higher RPM's while still in gear, where the throttle is closed but the engine is pumping like crazy).
I would want to nail that down for my own edification, even if it doesnt help fix the issue.
Good luck.
I would want to nail that down for my own edification, even if it doesnt help fix the issue.
Good luck.
fidstang
New Member
If you have oil on the spark plugs when you pull them out your rockers might be improperly loaded (tightening sequence) or the valve guides are gone as 90mustanggt said. I thought black smoke was rich, blue smoke was oil and white smoke is lean. Also, when do you get the black smoke? under WOT or when you let off to shift, is it while at idle?
fidstang
New Member
Have any pictures of the plugs. To me it sounds like your injectors are staying open to long. What pressure are you getting with the vacum line off.? Do you have an aftermarket chip installed or tuning done? What plugs do you have? maybe they're tp cold of a range. Just thoughts. I would let the rings set in for the break in period then see how things are. Only 20 miles isn't enough for them to set in. I know that oil is blue smoke and you said it was black. If you don't want to wait take it to get tuned or play with the timing to see what it likes. Seems to me that if black soot is building up on the plugs it would be a spark issue. Not burning the fuel or a restriction of the exhuast. Which could be from improperly tightening of the rockers.
The guy that rebuilt my engine is a Master rebuilder. I doubt that his tolerances were improper in any way. Something is very wrong however in that the car had no such issues prior to taking out the engine and rebuilding the car. I originally had factory spec motorcraft plugs in the engine. I took those out and replaced them with Autolites. No pics of the old plugs, but like I said they were sooty from carbon with no traces of oil. I did not want to drive the car any more than I did with it running this way. No chips or tuning either. The fuel pressure regulator and injectors were replaced after the rebuild and the same condition exist.
I am just at a loss for solutions and trying to figure out my next step.
I am just at a loss for solutions and trying to figure out my next step.
fidstang
New Member
You said the motor was rebuilt, did that include the cylinder heads? Just trying to narrow down the list. Have you asked the engine builder to look at it? If the heads were untouched and the only thing that was worked on is the short block. I would suspect the short block to be the issue, as that is the only part that has been worked on.
The entire engine was dissassembled and given the full machine shop treatment. The cylinder heads were completely rebuilt. The compression test revealed solid numbers. Don't think its the motor. Some sort of computer or sensor problem is more than likely the culprit.
fidstang
New Member
Have you checked the pvc/baffle. Maybe, there is a vacum leak there or a cracked intake. Dumb question, but, what would happen if the MAF was facing the wrong direction? ( I've always wondered that)
I don't think the MAF is that easily reversed - different size inlet versus outlet. Well, on mine it is, anyway...
This all sounds a lot like what's going on with my car. I'm getting the same rich condition, though not quite as severe as yours - just chewing up my gas mileage a bit, throwing rich codes, and backfiring between the WOT 1-2 or 2-3 shift with a puff of grayish smoke. Subscribing...
This all sounds a lot like what's going on with my car. I'm getting the same rich condition, though not quite as severe as yours - just chewing up my gas mileage a bit, throwing rich codes, and backfiring between the WOT 1-2 or 2-3 shift with a puff of grayish smoke. Subscribing...
From the code you got, it seems that the O2 sensors are not working like they should. The 43 code says they are not switching and providing signal to the computer.
There's the text on how to measure the output voltage to check their operation.
The following is a Quote from Charles O. Probst, Ford fuel Injection & Electronic Engine control:
"When the mixture is lean, the exhaust gas has oxygen, about the same amount as the ambient air. So the sensor will generate less than 400 Millivolts. Remember lean = less voltage.
When the mixture is rich, there's less oxygen in the exhaust than in the ambient air , so voltage is generated between the two sides of the tip. The voltage is greater than 600 millivolts. Remember rich = more voltage.
Here's a tip: the newer the sensor, the more the voltage changes, swinging from as low as 0.1 volt to as much as 0.9 volt. As an oxygen sensor ages, the voltage changes get smaller and slower - the voltage change lags behind the change in exhaust gas oxygen.
Because the oxygen sensor generates its own voltage, never apply voltage and never measure resistance of the sensor circuit. To measure voltage signals, use an analog voltmeter with a high input impedance, at least 10 megohms. Remember, a digital voltmeter will average a changing voltage." End Quote
Measuring the O2 sensor voltage at the computer will give you a good idea of how well they are working. You'll have to pull the passenger side kick panel off to gain access to the computer connector. Remove the plastic wiring cover to get to the back side of the wiring. Use a safety pin or paper clip to probe the connections from the rear. The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter.
Most of the common multimeters have a resistance scale. Be sure the O2 sensors are disconnected and measure the resistance from the O2 sensor body harness to the pins on the computer.
Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter. Do not attempt to measure the resistance of the O2 sensors, it may damage them.
The O2 sensor ground (orange wire with a ring terminal on it) is in the wiring harness for the fuel injection wiring. I grounded mine to one of the intake manifold bolts
There's the text on how to measure the output voltage to check their operation.
The following is a Quote from Charles O. Probst, Ford fuel Injection & Electronic Engine control:
"When the mixture is lean, the exhaust gas has oxygen, about the same amount as the ambient air. So the sensor will generate less than 400 Millivolts. Remember lean = less voltage.
When the mixture is rich, there's less oxygen in the exhaust than in the ambient air , so voltage is generated between the two sides of the tip. The voltage is greater than 600 millivolts. Remember rich = more voltage.
Here's a tip: the newer the sensor, the more the voltage changes, swinging from as low as 0.1 volt to as much as 0.9 volt. As an oxygen sensor ages, the voltage changes get smaller and slower - the voltage change lags behind the change in exhaust gas oxygen.
Because the oxygen sensor generates its own voltage, never apply voltage and never measure resistance of the sensor circuit. To measure voltage signals, use an analog voltmeter with a high input impedance, at least 10 megohms. Remember, a digital voltmeter will average a changing voltage." End Quote
Measuring the O2 sensor voltage at the computer will give you a good idea of how well they are working. You'll have to pull the passenger side kick panel off to gain access to the computer connector. Remove the plastic wiring cover to get to the back side of the wiring. Use a safety pin or paper clip to probe the connections from the rear. The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter.
Most of the common multimeters have a resistance scale. Be sure the O2 sensors are disconnected and measure the resistance from the O2 sensor body harness to the pins on the computer.
Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter. Do not attempt to measure the resistance of the O2 sensors, it may damage them.
The O2 sensor ground (orange wire with a ring terminal on it) is in the wiring harness for the fuel injection wiring. I grounded mine to one of the intake manifold bolts
Does the fact that the engine was off and not up to normal operating temperature impact the signal from the O2 sensor? I would think so as the code description tells you to run the car at 2,000 RPM's until it the water temp reaches normal and to shut it off and see if you still pull the O2 code. But I will test them any way to see what the voltage is. My EGR and sensor are original equipment, so that may be a source as well.
PROBLEM SOLVED
Tonight I cleaned the EGR and IAC. Replaced the TFI module and found that the vacuum line to the MAP was unconnected.
No more smoke out of the exhaust and the car idles better. I let it come up to temp and set the timing at 12 BTDC.
It runs 100% better now and seems to be good to go. Sometimes its the little things that you overlook I suppose. Now I can get the 450 miles out of the way for the clutch break in.
Tonight I cleaned the EGR and IAC. Replaced the TFI module and found that the vacuum line to the MAP was unconnected.
No more smoke out of the exhaust and the car idles better. I let it come up to temp and set the timing at 12 BTDC.
It runs 100% better now and seems to be good to go. Sometimes its the little things that you overlook I suppose. Now I can get the 450 miles out of the way for the clutch break in.
So, all that smoke was from a disconnected MAP sensor? ... or a cumulative thing combined with a dirty EGR, IAC, and old TFI module?
Its hard to say for sure, but the car was dumping too much fuel and burning it very quickly when I drove it. I only cleaned the EGR and IAC due to the sooty residue found on the first set of plugs and what was coming out the exhaust. I'm sure that I was not getting the proper spark with a bad module and the MAP being disconnected had something to do with not allowing the ECU to regulate the injectors properly.
DMAN302
My mom says thanks for the pearl necklace.
Unpluged map was definately the issue regarding the vac readings...plus look at all the nice new parts you've now added, they were likely tired anyway. 
Too often we end up throwing money at the problems looking for an easy fix...been guilty of that myself.
Too often we end up throwing money at the problems looking for an easy fix...been guilty of that myself.
Similar threads
