94 SS Loses power under positive manifold pressure

alcyone · Post by **alcyone** » Thu Oct 20, 2005 2:33 pm

Hey all-

I just picked up a 94 SS from another member here. Fantastic car! But, some issues. Here are all of the problems:

*Check engine light on. Many varying sensor codes thrown.
*Car sometimes hard-starts, other times it starts right up.
*Car sometimes loses power when manifold pressure is positive. As soon as the car goes into boost, it loses power right away, let the manifold pressure return to negative, and it runs perfectly.

Any thoughts from the experts?

Mike

legacy92ej22t · Post by **legacy92ej22t** » Thu Oct 20, 2005 2:47 pm

On the positive pressure problem. It sounds like it could be an issue with the MAP sensor that is causing that problem. Is that one of your codes?

alcyone · Post by **alcyone** » Thu Oct 20, 2005 8:57 pm

Some new information:

I hooked up the select monitor today and got the following codes:

Injector #1
Coolant Temp Sensor
Air Flow Meter

Now, the interesting part. I tried to clear the codes, and they wouldnt clear. The select monitor indicated they were cleared, but when i went back into the check codes screen, they were still there. This kind of makes me think it may be a problem with the computer. What do you think?

Mike

vrg3 · Post by **vrg3** » Fri Oct 21, 2005 1:07 am

You removed the key when the Select Monitor said "KEY OFF" and then waited about ten seconds before putting it back in?

alcyone · Post by **alcyone** » Fri Oct 21, 2005 8:41 pm

vrg3 wrote:You removed the key when the Select Monitor said "KEY OFF" and then waited about ten seconds before putting it back in?

I turned the key to the off position, but didn't remove it. Does this make a difference?

Mike

0perose · Post by **0perose** » Fri Oct 21, 2005 10:16 pm

this is off topic, but I couldn't help but notice your username.... I too am an alcyone owner... just the father of your alcyone

(3 XT6's)

THAWA · Post by **THAWA** » Sat Oct 22, 2005 2:20 am

Hi Mike, good to see you back round these parts.

For the third problem also inspect all the vacuum hoses. If they are leaking and they have anything to do with the wastegate solenoid, pressure exchange solenoid, or MAP sensor as Matt pointed out, it will throw a code and cause the exact problem you are describing.

Something i've noticed is that when one code is thrown, it causes the other sensors to go nutty and sometimes throw a code. It's possible you only have one problem, or two, but the other codes were throw because of the original problem. The MAF sensor does this a lot on my car.

vrg3 · Post by **vrg3** » Sat Oct 22, 2005 4:15 am

No, you shouldn't have to remove it... but did you wait for several seconds before turning it back on? Cuz it shouldn't be possible for codes to remain after using the Select Monitor to clear them and before starting the engine again...

91White-T · Post by **91White-T** » Sat Oct 22, 2005 4:01 pm

This may sound obvious, but have you checked for a leak in the intake tube? Maybe one that opens under boost?

555BCTurbo · Post by **555BCTurbo** » Fri Oct 28, 2005 6:41 am

I can just about guarantee your Coolant Temp Sensor is causing you the most problems.

When my car's CTS went out, it started hard, ran rich, idled like crap, shuddered on boost, all sorts of stuff...

It's worth the $35!!

legacycentral bbs

A forum for 89-94 BC-BF(BJ) Legacy Owners and Fans

94 SS Loses power under positive manifold pressure

94 SS Loses power under positive manifold pressure