EDIT: ENGINE DROPPED A VALVE ---------------------------------------------------------------------------
1986 2.8 V6 GT 65K miles.
For the most part, the car runs very well. It usually starts right up when cold. Idles at 800 rpm. Gets 22-24 mpg. Decent acceleration. No major complaints.
Sometimes it stalls out for no reason while idling or going very slow. It usually takes several cranks to get it going again. That is about the worst thing I can say is happening.
The engine light comes on usually when I'm sitting still for an extended period, like waiting in a drive-thru line. It always goes out on its own. I pulled the codes and found Code 44.
I did some research and found that many things can cause this, weak fuel pump, dirty fuel filter, deteriorating submerged hose inside the tank, stuck injector, O2 Sensor, MAP sensor, vacuum leak. Possibly others.
Here's what I know, I checked the fuel pressure with a gauge and after one prime cycle, it showed 40 psi. Primed it again and got 44 psi. Started it up and at idle, the pressure is 35 psi. When revving it, as the rpms are increasing, it jumps to 42. When the rpms settle at a set rate, even at a higher-than-idle rate, the pressure settles back at 35 psi.
That sounds pretty good but maybe not perfect. What do you think about the fuel pressure?
As far as vacuum, my Cruise Control works very well. Not sure if that is in any way a test of the vaccum system.
I changed the PCV valve recently. I have a new fuel filter to go in it. Should that be my next step? Maybe the MAP sensor? I have a few extra of them.
If you don't know how old the 02 sensor is, you should probably replace it. They are inexpensive. The other thing I would do would be to run some injector cleaner through. If the injectors are just a little bit plugged up the computer will think 'lean'.
Fuel pressure sounds fine.
[This message has been edited by Gall757 (edited 09-16-2013).]
If you don't know how old the 02 sensor is, you should probably replace it. They are inexpensive. The other thing I would do would be to run some injector cleaner through. If the injectors are just a little bit plugged up the computer will think 'lean'.
Fuel pressure sounds fine.
The light came on again today. I'll try the O2 and injector cleaner.
I had this problem about a month ago, It stalled on my 8 times in a row. I replaced the 02 right away along with the spark plugs and plug wires. haven't had any reliablity or drivablity issues so far. I will be getting injector cleaner next.
The SES light is coming on more frequently. I bought a new O2 sensor and checked the codes again. In addition to the 44, now I also have a code 13. I think that is pretty definitive that it's the O2 sensor. I'll prolly go out and swap it between classes. That way I can re-test it on the highway on the way home tonight.
My spark plugs are only a few thousand miles old. I also re-built the distributor. The plug wires are not new. Might be original.
I put the new O2 sensor in, cleared the old codes and drove home. Some interstate, some in-town, stopped at an ATM, went for gas. Pretty good variation of driving situations. I checked for codes. None there. I didn't see the light either. Everything looks good.
It also appears that my idle speed has dropped 100 RPMs. Now it idles closer to 700 RPMs. Accelleration seems to be a tad better. Maybe not. I'm kinda sticking my foot in it to see if it is running any better. Obviously not a scientific test. It is a fun test, though!
Plusses to all those who didn't have one previously!
It did the stalling thing today. It happens the same way every time. Starts easily when cold. Runs well till I shut it off. Doesn't want to start when it is warmed up after shutting it off for a few minutes. It fires immediately but it can't seem to keep the RPMs up and just dies. It always sounds strong and responds to throttle imput. It just needs to be feathered to keep it going when this happens.
Since changing the MAP, it has stalled twice on a first-time-start attempt. Both times the car kept running after the second start attempt. I did not have to use the throttle at all to keep it running.
This is an improvement over what had been happening. Before, when this happened, it would take multiple attempts to start it and keep it running. I had to feather the gas before to keep it running for a few seconds before it would idle on its own. I have not checked for codes since changing the MAP. I'll try to do that tomorrow.
It had been running very well. Drove to my first class. Drove home. Drove to my evening class, car sat for about an hour and a half. Went out to start it and it did the multiple no-go starting routine. I finally gave in and feathered the gas to keep it running and after a few seconds, it decided to idle. I started home.
I was on the interstate doing about 60mph and I started hearing a knocking noise. Then the noise changed to a different knocking noise, then it changed to a third different knocking noise. The car was still running and I was on an incline. I crested the hill and the noise stopped. I checked all the gauges and everything looked good.
I got to my exit and it started again. I debated stopping for fear that if I did, I wouldn't make it home. Well I stopped. It died. I checked the codes. Code 33 was set. I swapped the MAP again. It didn't help. The car was running like crap and it sounded even worse!
It was smoking like a mosquito fogger! It had never smoked before. I was able to limp home by coasting and revving and popping it into Drive.
I started reading the Code 33 threads. Someone suggested trying to start the car with the MAP wiring disconnected. I did that. It did run a little better but couldn't hold the idle and eventually died. Then I could hear a ticking noise at the engine.
I know the fuel pump is good. I could hear it prime. Another suggestion I read was to change the ignition coil. I'll prolly try that as well. It is too dark to look for vacuum leaks tonight.
Does any of this sound familiar to anyone? Was the "knocking" noise caused by the ECM getting false readings and trying to compensate? Why do you suppose it was smoking so badly? Any other thoughts?
Thanks in advance, Jonathan
[This message has been edited by Boostdreamer (edited 09-23-2013).]
There are some tricky vacuum tube connections right around the MAP sensor. If one of those is not tight the car will sound awful.....mine looked good but one tube was not quite sealed.
44 means ECM is trying to Adding fuel to comp lean condition and fails.
You do have ECM scan tool? Use it. My guess is most times BLM is high. A small vac leak or a plugged injector(s) etc can do that.
Check brake booster and line to it when looking for a leak. Easy way just pinch off a line and watch BLM 1-2 minutes. (Do Not Drive when booster line is pinch.)
Can't remember if V6 have enough room to pull a injector plug... That might help finding a weak/plugged injector. I think BLM should change to normal range if 1-2 is weak.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Can I buy new rubber hose for the vacuum lines at an auto parts store? What sizes of hose will I need and how much of each size to completely re-do a 2.8 V6?
It sounds like there is something broken inside the engine. The knocking varies as the RPMs do. It is smoking like crazy. I didn't find any vacuum tube damage. I swapped the ignition coil. Didn't help.
Let it cool down and see how it reacts when cold. Can you get a vid to see how your car sounds? Make sure your distributor is tight and also take a look at the pick up sensor inside of it. While you at it check for play in the distributor shaft.
Let it cool down and see how it reacts when cold. Can you get a vid to see how your car sounds? Make sure your distributor is tight and also take a look at the pick up sensor inside of it. While you at it check for play in the distributor shaft.
Yeah, I had the same thought. I tried it the next day and there was no improvement. If I had to nail it down with my best guess, I'd say that the head gasket failed and allowed coolant into a cylinder and it crunched the rod. The car went through a three-part series of different knocking noises as it was going down the highway.
Like I said, it is smoking like crazy now and it never smoked at all before. White smoke, so that sounds like coolant. It sucks. That engine only had 67 thousand miles on it. All fluids were good, new spark plugs, cap and rotor, re-built distributor, 1988 Oil Pressure Sending Unit, new O2 sensor, etc.
I did everything I could do to make her last. I guess it was just her time.
Jonathan
[This message has been edited by Boostdreamer (edited 09-26-2013).]
Oops. I thought this was my other thread. I'll let this thread die. I've decided that the engine is finished until such time as someone tears it down and re-builds it. I won't be the one doing that so...I'm going to swap engines.
I will be getting injector cleaner next.
