Mass air flow , how to trouble shoot brake booster vacum leak

[jyoung1z]

HI, a couple thing on a s/c 1995 Riviera. Have had the check engine light come on and then go off. Replace EGR and O2 sensor. The car drops rpm's when I come to a stop while driving. Then the engine - car rocks alittle.
Do to rpm's drop to 4-500 , put tranny in N and rpms go back to were they should.

I cleaned the MAF sensor Sunday, put the connector back on - started car it ran good, better throttle response, ect... I unplugged the connector with car running and got no throttle responce or rpm's when tried to rev it up. Plugged back in , ran pretty good.

Drove car , same thing , light comes back on and drop of rpm's at any stoplight stopsign.

Today went to look at other issure " heater blower motor " got done with that and my dad and I heard a " Vacuum Leak. What is was is the vacuum line from the " Brake power booster " The big line going to engine.

He unplugged it and closed it off with his finger and the Vacuum leak went away. I then unpluged MAF sensor and the car idled much better even when I put car in gear.

Plugged everything back, Drove home " NO check engine light on the whole 13 mile trip. Unplugged MAF and engine ran like heck again. I took off the brake vacuum line plugged with finger and it ran better.

So I guess I need to replace brake vacuum booster first. Then see how it runs - drives ect.

Is there any thing else anyone could help me trouble shoot the " check engine light - Maf sensor , with? Any troubleshooting info would be appreciated.

Thank you

James YOung

[jyoung1z]

Originally Posted by jyoung1z

HI, a couple thing on a s/c 1995 Riviera. Have had the check engine light come on and then go off. Replace EGR and O2 sensor. The car drops rpm's when I come to a stop while driving. Then the engine - car rocks alittle.
Do to rpm's drop to 4-500 , put tranny in N and rpms go back to were they should.

I cleaned the MAF sensor Sunday, put the connector back on - started car it ran good, better throttle response, ect... I unplugged the connector with car running and got no throttle responce or rpm's when tried to rev it up. Plugged back in , ran pretty good.

Drove car , same thing , light comes back on and drop of rpm's at any stoplight stopsign.

Today went to look at other issure " heater blower motor " got done with that and my dad and I heard a " Vacuum Leak. What is was is the vacuum line from the " Brake power booster " The big line going to engine.

He unplugged it and closed it off with his finger and the Vacuum leak went away. I then unpluged MAF sensor and the car idled much better even when I put car in gear.

Plugged everything back, Drove home " NO check engine light on the whole 13 mile trip. Unplugged MAF and engine ran like heck again. I took off the brake vacuum line plugged with finger and it ran better.

So I guess I need to replace brake vacuum booster first. Then see how it runs - drives ect.

Is there any thing else anyone could help me trouble shoot the " check engine light - Maf sensor , with? Any troubleshooting info would be appreciated.

Thank you

James YOung

Fixed my own problems, the problems mentioned above were do to a Vaccum leak in the Brake Power Booster. Replaced that and no problems with the car at all now. Runs like Champ now.

Have a good day and hopefully someone can fix there Rivier's problem with this info.

[PimpMyRiv82]

I had the same problem with mine. My vacuum line wasnt hooked up. Retard told me that they install two lines, one being a dummy line and the other one you need. I shouldve slapped him in the mouth for that. Luckily my uncle hooked me up later that day and the shuddering stopped and the car ran alot smoother..but that sensor problem, Im trying to figure out myself. I dont have a plug on the harness to the MAP sensor I think..the one that goes on the top by the passenger side, really big sensor, right by the alternator...