1994 Chevy Lumina Van Problem

Hi Everyone,

When I'm driving down the road, the engine surges and then bogs down and I notice that the odometer increased by 10 mpg or so, but the speed doesn't increase. Sometimes the engine will quit running. Are there any ideas what could be causing this? I'm really hoping it's not my transmission.

On cold mornings the check engine light comes on when I first start the engine. It runs for a couple of seconds and then quits. I keep trying to start it until it starts without the check engine. The other night it took 5 times to start and keep running. I noticed a strong smell of gas at that time. My OBD-1 connector is a 12 pin connector, but it doesn't have a wire going to the B position (diagnostic terminal). Someone said I have something in between OBD-01 and OBD-2 so I can't short A and B together to make the Check Engine Light Flash to get codes. I don't know anyone with an OBD-1 scanner or have the money to pay someone to do it right now.

I replaced the spark plugs and wires. When I compared the plugs that I took out to the photos in the Chilton manual, it read that they had been in too long because the gap had increased to 0.09 in. They were a brownish white color

I found some bad vacuum hoses and replaced them. I have a vacuum pump that I used to check to make sure I can create a vacuum going to different components. This is what I found:

  1. The vacuum hose going to the Transmission does not leak.
  2. The vacuum hose going to the Evaporative Canister Purge Valve leaks slowly.
  3. The vacuum hose going to the Evaporative Canister does not hold a vacuum at all.
  4. The vacuum hose going to the Fuel Pressure Regulator does not leak.

The only thing that I haven't checked for vacuum leaks is the Cruise Control. I have to remove components that are on top of it to see what condition the vacuum hose is in and where it goes.

If someone has any ideas on what else to check or knows what is going on I would really appreciate some help.

Thanks in advance,

Ken

Reply to
Ken
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I wish my vehicles would increase by 10mpg while I was driving down the road. Why don't you try that again though. I'm sure you meant your tachometer (not your odometer), but how many RPM does the engine increase while driving? 10 would not be noticable on a tach. If you are experiencing RPM increases there's a good chance it's the torque converter lockup. You can verify this by driving and lightly touching the brake pedal. Just touch it and you should see/hear/feel the lockup drop - the RPM will rise some. If that is similar to what you are experiencing while having your problem then you are on you way to knowing what's wrong.

What motor is in your van?

Reply to
Mike Marlow

I'm sorry. I meant the speedometer quickly increases 10 mph and then drops back down.

I have a 3.8 liter 6 cylinder.

Reply to
Ken

I think you're going to have no choice but to get the vehicle scanned Ken.

Reply to
Mike Marlow

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