Buick problem

Sparticle · #1 09/01/13, 08:12 AM

Hi. We have a 89 Buick Century Estate Wagon, 3.3 liter. Been having problems. Code showed mass airflow sensor. Cleaned it out and replaced the connector, which might have been bad. The car starts but stops immediately. Unplug the alternator and it runs but its rough. While running, plug in the alternator, it dies. Any ideas? Thanks.

agmantoo · #2 09/01/13, 11:24 AM

Will the vehicle continue to run as long as the ignition switch is held in the start position?

Sparticle · #3 09/01/13, 11:45 AM

Not sure I understand the question. The car runs with the alternator disconnected. When I connect the alternator, it stops. The key is in the normal run position.

rickpaul · #4 09/01/13, 12:14 PM

http://www.agcoauto.com/content/

Try this site, they have helped a lot, you can either call or e-mail them

agmantoo · #5 09/01/13, 12:17 PM

The car starts but stops immediately. I read this is while the alternator is connected. With the alternator disconnected it will continue to run but runs rough. I want to know with the alternator connected and you hold the ignition in the start position will the car continue to run? I also would like to know The car starts but stops immediately. if all the instrument lights come on when it dies?

Sparticle · #6 09/01/13, 12:26 PM

I am sorry for not understanding. The car tries to start as long as the key is in the start position, it won't start until I let the key go to run and then it dies. A couple of lights come on when it dies.

agmantoo · #7 09/01/13, 12:45 PM

The conclusion (best guess) I come to is that the alternator is shorted. This short is then disabling the computer since the 12 volts which the alternator should be delivering is instead sending the computer input (12 volts) to ground. The rough running is because the computer is not operating as it should.

I have seen a similar situation on a Honda where the ignition switch created a problem due to the manner the switch design handled the distribution of the vehicle power.

Obviously I cannot state for certain that substituting the alternator will fix your problem but I believe it would be worth the try. I can tell you I have seen a number of alternators short. PS...it is actually the regulator in the alternator that shorts. The diodes blow.

Sparticle · #8 09/01/13, 01:09 PM

I put in a new alternator this morning. I thought there was a knock/rattle coming from it so I replaced it. Another thing: I noticed recently that the metal fresh air intake tube was touching the positive battery terminal and sparking. I fixed it. Do you think it damaged the computer?

agmantoo · #9 09/01/13, 04:41 PM

I do not have a schematic of the vehicle and I am uncertain as to what and how the fresh air intake and the materials thereof would be configured into the overall electronics. I know that many of the computer functions are controlled by the making and breaking of the ground (negative side of the DC voltage) and you would be sending the positive voltage to ground. Whether this could feed to the computer is unknown to me. I would expect blown fuses however.

dodgewc · #10 09/02/13, 06:12 PM

unplug the mass airflow sensor
if it continues to start and stay running, it needs a maf

Sparticle · #11 09/12/13, 05:47 PM

I had to take to a shop. It needed: a mass air flow sensor, an injector, and a computer. The injector had a short in it that messed up the computer. Got the car back today and it has a terrible shake now. The mechanic said it was the torque converter. It shakes when accelerating up a hill, smooths out when it shifts to a lower gear. Didn't have this problem before all this mass air flow sensor stuff happened. Did replacing these parts cause this other problem to show up?

dodgewc · #12 09/13/13, 07:41 PM

the 3.3 isn't the smoothest running engine, but you probably have a misfire
check the coil to plug connection i'll lay odds the 2/5 coil is carbon-tracked

Sparticle · #13 09/16/13, 05:16 PM

Yes, a misfire. My NEW mechanic has the car. Cylinder one doesn't fire at all. The quad things are showing up in the codes. The car did not act like it misfired before I took it to the former mechanic. I don't understand what happened while it was at the former mechanic to make it misfire. The belt tensioner makes a rattle, it always has, since we've had it, 4 months. Thanks all.

Bret4207 · #14 09/17/13, 07:01 AM

When you unhitch an alternator on a running engine, you generally fry the alternator. Same as when you "test" an alternator by unhooking a running vehicles positive battery terminal. Yes, we could do that back int he day with a generator, but not with an alternator.