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I got a 1987 New Yorker from my mother-in-law. It has a 2.2 liter turbo, and has 161000 miles and has been setting up for a while. It would hardly run when I started working on it. I put on a new oxigen sensor and trottle positioning sensor, as well as a tune up. I was able to drive it from Tennessee to South Carolina. What it is doing now is when I start it, it idles high for about 10 seconds. Then the idle drops, but is still a little high. When I push the accelerator as if I am trying to start from stop , the engine surges up and down continuously. If I barely push the accelerator, it will accelerate, or if I push the accelerator to the floor, it revs up like it should. I checked the diagnostic code through the ignition switch and get a code 15, which is the distance switch. Could the distance switch cause this problem? If so, where is it located. If not, what could be causing my problem.
Tom
Answer -
Hi Tom,
The distance sensor not only drives the speedo/odo but its pulse rate is used to regulate the mixture so it might contibute to a surge. It is located on the top of the trans axle housing which is where the half shafts are inserted. It has an electrical plug which you would want to check for clean contacts and a firm connection. Then disconnect the battery for a few minotes to erase the 15 code and then drive it again and if the code returns it probably means the gear on the shaft of the sensor is damaged. You remove one bolt to take out the sensor. You may be able to get a new gear from a dealer, or a wreck. The gear is often damaged if a mechanic yanks out the right half shaft without first removing the sensor. If fixing the distance signal doesn't solve the surging I would look for a vacuum leak at the throttle body or at any of the seveal vacuum hoses associated with the intake manifold. If not that, then check the fuel system pressure which should be about 55 psi.
Let me know what happens, and good luck.
Roland
Roland:
The distance sensor is OK. Tghe computer is not giving me any further readings. Since I don't have the equipment to check the fuel pressure, and I only know how to check for vacumn leaks visually. I guess it is time to see a mechanic. Unless you have any suggestions.
Thanks for everything.
Tom
Answer -
Hi Tom,
The absence of a fault code makes things a bit more difficult. It may be something that is not subject to oversight by the controller (such as a partially clogged catalytic converter, or a MAP sensor (or other sensor) that is off-value but not non-functional, or a vacuum leak in the line that goes to the MAP that is changing as you put torque on the drivetrain, or the fuel pump, or a loose electrical connector on the harness for the injectors). How does it behave once you have it up to speed, does it still surge? So try looking over the vacuum lines completely using the underhood sticker as a roadmap to check the system from the intake manifold to everything that is shown on the sticker. Maybe a fault code will show up soon.
If none of this works out, then a scan of the controller at a dealership with a good tune-up mechanic using a DRB that shows all the operating parameters will pin-point the problem. You might also want to check the mechanical linkage at the turbo for binding or disconnection.
Let me know.
Roland
Roland:
When I first started working on the car, the computer was showing the MAP sensor as bad. I found the MAP sensor relay was clogged.I couldn't find one, but unclogged the old one. Now, when I disconnect the vacumn line from the MAP sensor, the engine idles up.
I have checked all the electrical connectors. They look good and have been cleaned. When I drive the car, it does fine until I have to accelerate. Then the surging begins.
I havwe checked the vacumn lines using the uder hood diagram. I have not removed the vacumn lines from the protective wrapping. I will do that and see if anything is there.
I can't tell if the vacumn purge silonoids on the fire wall is working or even if the vacumn lines are hooked up correctly. They have lines coming from the top and bottom. When I disconnect some of the lines, nothing happens. Others make the engine idle up or down. Any suggestions on those?
Tom
Answer -
Hi Tom,
As long as the vacuum lines are solid and attached I would not spend any more time on that issue. But if possible without doing damage I would check the vacuum lines that are covered by a wrapping IF they are positioned over the exhaust manifold because that heat can really fry the hose, or if easier, test them by removing at each end and sucking on one end while plugging the other end. Also check the hoses for the PCV valve and the valve for 'action' because those get really brittle.
Because the problem seems to be at speed and then accelerating, the possibility of a plugged catalytic converter or the fuel pump (or fuel filter?) raise a real question. So maybe those would be worth testing (I believe a good muffler shop can check the converter, and similarly a fuel pressure gauge that reads up to 55 psi just needs to be attached to a port on the fuel rail.
Roland
Roland:
I know I am asking a lot of questions. And I REALLY do thank you for all your help.
With this car, I noticed that the rod on the waste gate that operates the turbo does not move when the engine is reved up. I can move the rod easily if I grab it with a pair of pliers and there is vacumn going to it. Could this be my problem?
Tom
AnswerHi Tom,
Unfortunately my experience does not include turbocharger functioning. May I suggest that you try one of the on-line groups that has participants with those engines (e.g. dodgegarage, or the yahoo autos groups for the Chrysler AC-AY bodies, or the Chrysler LeBaron Club. There are some ecperienced folks who can tell you how the wastegate and its rod should function. It would seem that the valve should not be the stiff, but I am a novice on that. Whether that is the problem with the engine performance is uncertain to me. I wouldn't get to focussed on it but keep an open mind about the other possibilities I mentioned earlier.
Roland
