QuestionQUESTION: Hello,
I could really use some assistance with this problem, it really has me puzzled.
I have a 91 New Yorker 3.3l with 136k miles that the engine will not run. It tries to start but dies as soon as the starter disengages. Up to this point the car has never had any engine issues.
Back story:
Nothing unusual happened on my morning commute. Later that morning I filled up the gas tank and then got on the freeway. I had only been on the freeway for about three miles when I needed to pass a car. When my car began to accelerate I heard a noise that is similar to an exhaust manifold gasket giving away on one cylinder. Kind of like a “puff...puff…puff” sound to slow to be once every revolution of the crank shaft. I have never had an engine start to misfire on one cylinder before so it did not enter my mind yet that this could also be what I am hearing. Anyways, as I let off the gas and let the speed fall back to the cruse control the sound goes away. With the cruse set and 70mph over the next couple of miles I repeat the scenario; accelerate hear the sound, fall back to 70mph the sound goes away. I figured I needed to check my exhaust bolts until the sound started to be noticeable at 70mph, about seven miles after the first signs of trouble. Then not to long after that the noise started to sound like two cylinders where “puffing” then three! At this point I decided I needed to get off the freeway only 16 miles after filling up. When I touched the breaks to turn off the cruse control, the RPMs dropped and the engine died. While coasting down the exit ramp I tried to start the car (with the transmission in neutral) and all it would do is attempt to start but would not get past a stumble of misfires. I tried holding down the gas while starting it, out of desperation, and made the engine run backwards for a few seconds, blowing power steering fluid all over the engine compartment. The misadventure ended with me not being able to restart the car. It tries to start but will not get past stumbling, misfiring and rocking on the engine mounts. Giving it some gas makes it try harder, but it still will not run.
Trouble shooting I have done:
There is no error codes, “12 and 55” are the only codes that show up. I have pulled spark plug #4 and made sure there was a spark. Fuel pressure is dead on at 48psi when starting. Needless to say the fuel pump sounds like it is working. Coil pack resistance checked out, but I tried a new coil pack anyways and it did not make a difference. I have also replaced the crank and cam sensors to no avail. I have tried unplugging the O2 sensor and the MAP sensor, separately and together, still no improvements. In desperation, I went through the effort to pull the timing chain cover and the sprocket markers line up, and chain slack is within spec. After getting everything back together, I still have to same issue, still with no error codes.
My gut feeling is this is a “weak spark” issue and that maybe the PCM (computer) is bad.
What else could be I be missing?
Thank you for your time,
Jason
ANSWER: Hi Jason,
Take a look at the exhaust gas recirculation valve which may well be stuck ajar. It has a flange between the body and the vacuum actuator and in that flange area is the valve stem that has a slot. Move the stem back and forth with the tip of a screwdriver in the slot to see if it moves freely against spring-action that tries to close it. If it isn't closing all the way then spray some WD-40 on the stem where it enters the valve and then move the stem to free it up. Once it is closing tightly that may solve the no start issue and all the rest.
Roland
---------- FOLLOW-UP ----------
QUESTION: I do not think I have a EGR valve. There is the mounting point on the air intake just behind the MAP sensor. My repair book shows it located there, but I do not have anything there. No loose wires, no vacuum line or hoses. Is it located somewhere else? I am not the first owner, could it have been removed? If it was removed it was not done hastily because there is no sign it was ever there.
AnswerPS Another possibility is that the catalytic converter's honeycomb has come loose and is blocking your exhaust gases.
Hi Jason,
When you said 'freeway' I immediately thought 'a California car'. The 3.3L sold in California in '90 has the egr, otherwise not. What does the sticker under the hood show? any sign of an egr there? If it were there it would be in a small diameter pipe that branches off the middle of the rear exhaust manifold and runs back to the area underneath the throttle body where the valve would be located.
Without any codes I am at a loss too; that is why I thought of the egr also. Another possibility is the MAP sensor has gone inaccurate without doing it so badly as to set a fault code. That happened to me with my '89 2.5L. It sounds to me like a mixture issue rather than a spark issue. That is why I thought of the egr and now the MAP. I am not sure that unplugging the MAP would reveal a MAP problem if the the MAP were inaccurate. If you have access to a DRB II readout box then you could look at things like the MAP reading.
That is how I found out it was my MAP that caused the no start with no codes. Where are you located?
Roland
