Help! 92 Q oil change and problems!

[1watson]

Just purchased a 92 Q45 that is in sweet condition with 98K. it is a "basic" Q model . A lady owned it out of Atlanta who moved to MI and decided to sell the Q. Absolutely clean but was in need of an oil change.

I changed the oil and filter. While spending countless minutes pondering how to get to the oil filter, I decided to removed the air box and access it from above. Big mistake. I have the following problems that appeared immediately after the oil change:

1. Very difficult to start, starter spins for ever and car wont start until I press the gas pedal to floor. Once started car runs ok but "misses" under load intermittently. Car idles fine. I was reading a post last evening and found that the MAF sensor/harness perhaps could be teh problem.

2. The check engine light is lit

What must I do to restore previous condition.

[DAEDALUS]

The MAF is my first guess since it's attached to the top of the airbox. A bad connection would cause rough running, but not missing I don't think. The CEL might be related to the misfiring...check your knock sensors. I'll post a link to a procedure later.If you have to mash the pedal to the floor to get the car started, then it's flooded (pedal to the floor shuts off fuel at startup). Once the car is started, wiggle the MAF connector to see if there's any effect on the idle. You can either reset the check engine light manually, or disconnect the battery for 24 hours. The manual reset is more work, but the procedure will also reveal the error codes setting off the CEL to give more insight to the problem. How many miles have you put on the car since buying it?

[1watson]

Less than 400. I am certain that the MAF is the problem but it seems very strange that this occurs. Simply removed airbox cover and retaining screws, changed the filter and then immediately upon restarting, the CEL is lit and vehicle is dificult to start. Would you suggest changing the unit out, replacing the witing harness to the MAF or just resetting the computer to see if the proble is resolved ?

[DAEDALUS]

MAFs rarely go bad unless physically damaged. They aren't cheap. Do what you can to make sure the connection is good. Also, if you have a multimeter, take a voltage reading at the terminals with the car at idle. Make sure it doesn't jump around much and post what it is. Should be just over 1V I think. Do you have a service manual? A lot of the checks are in there. Look around and make sure there aren't any other harnesses and hoses that might have been knocked loose when you were taking the filter off. There's a hose under the plastic intake hose that runs back under the throttle body, one hose on top of the intake, and a couple small vacuum ones toward the front. Also check the purge cannister hoses.

[forecast]

I'd bet you broke a wire in the MAF harness. If the plastic coating had cracked previously and let water on the wires, the wire gets brittle and will break even if moved gently.

Check it with an ohm meter. Do you have a manual? If not a book manual (not CD) is an essential piece of equipment for any DIYer who dares to pop the hood. The manual shows which are the relevant connectors on the ECU terminal and how to test the MAF. Follow the intructions for checking the MAF both at the MAF itself and at the ECU, if the results are the same; bad MAF. if they different - bad wiring harness.

A broken wire would be consistent with problems you have, especially if the two broken ends remain in contact and form a variable resistance bridge, one momment full contacnt and a second later nothing and so on.

Dan

[DougQ45]

Sometimes the pins that are located inside the plastic connector plug get bent and do not properly crimp onto the electrode on the MAF. Look at the connector plug, are the pins not centered??crimped???, pushed out of the plug area where they do not make contact with the MAF???