OBD 1.5 Live Data Codes

Hi there,
I am trying to revive my 95 SC Rivi...
Changed air filter
Spark plugs
Cleaned injectors
I also sprayed Carb cleaner into the vacuum
But I still got a very rough idle...
It goes away on higher rpm



I am getting several codes and I also need your expertise on reading live data
Here are the videos:
https://youtu.be/JIHLhyfbkdM
https://www.youtube.com/shorts/P5ION2RhHvQ?feature=share

Have ordered this oxygen sensor:
https://www.ebay.com/itm/132943081466

And am also waiting for a can of Sea Foam

Could it be a vacuum leak from the gasket?
What else should I be doing?

BuickRivieraGeorgia wrote:

Hi there,
I am trying to revive my 95 SC Rivi...
Changed air filter
Spark plugs
Cleaned injectors
I also sprayed Carb cleaner into the vacuum
But I still got a very rough idle...
It goes away on higher rpm



I am getting several codes and I also need your expertise on reading live data
Here are the videos:
https://youtu.be/JIHLhyfbkdM
https://www.youtube.com/shorts/P5ION2RhHvQ?feature=share

Have ordered this oxygen sensor:
https://www.ebay.com/itm/132943081466

And am also waiting for a can of Sea Foam

Could it be a vacuum leak from the gasket?
What else should I be doing?

You should be searching for a scanner that reads live data for your vehicle. Your actron is helpful though.

In the meantime - rough idle that goes away with higher RPM isnt usually spark in my experience.
If you are using a K&N oiled air filter, un-install it and put in any decent paper one. The oil can mist off the filter and wreaks havoc downstream so until you solve this problem, don't do that.

You need to figure out if the wires to the MAF are damaged (happens) o if the MAF itslef is bad (no surprise there). An oiled filter will mess up the MAF, by the way.

This could be a vac leak but I would check the MAF first.

albertj wrote:

BuickRivieraGeorgia wrote:

Hi there,
I am trying to revive my 95 SC Rivi...
Changed air filter
Spark plugs
Cleaned injectors
I also sprayed Carb cleaner into the vacuum
But I still got a very rough idle...
It goes away on higher rpm



I am getting several codes and I also need your expertise on reading live data
Here are the videos:
https://youtu.be/JIHLhyfbkdM
https://www.youtube.com/shorts/P5ION2RhHvQ?feature=share

Have ordered this oxygen sensor:
https://www.ebay.com/itm/132943081466

And am also waiting for a can of Sea Foam

Could it be a vacuum leak from the gasket?
What else should I be doing?

You should be searching for a scanner that reads live data for your vehicle.  Your actron is helpful though.  

In the meantime - rough idle that goes away with higher RPM isnt usually spark in my experience.
If you are using a K&N oiled air filter, un-install it and put in any decent paper one.  The oil can mist off the filter and wreaks havoc downstream so until you solve this problem, don't do that.

You need to figure out if the wires to the MAF are damaged (happens) o if the MAF itslef is bad (no surprise there).  An oiled filter will mess up the MAF, by the way.

This could be a vac leak but I would check the MAF first.

I had K&N style filter but I reinstalled the stock air box & filter about a month ago...
The rough idle began about a week ago though... it ran great for a few days after changing sparks, filters & cleaning injectors, but then this happened.


The gas tank must also have a hole in it, because I cannot fill it all the way - it pours out anything over a certain amount...
So, I am guessing dirt must be getting through that hole in the tank and keeps clogging up the fuel system- is that something plausible?
Because I cannot find any vacuum leaks... I also had the antifreeze checked for CO, they said the gasket was fine....
I spray-clean the MAF this morning and added a bottle of injector cleaner to the tank- seemed to run a bit better, but the idle is still very rough...

Also, I got this Actron because I thought it could read live data! Are there better alternatives?

Thanks for the reply

Measure engine vacuum directly.  A healthy 3800 fully warm will make a solid 20" of vacuum in PARK.


In the trunk, under the carpeting is a removable access panel for the fuel pump.  You'll want to take a look at that.  A very common problem is that the metal tabs that hold the locking ring corrode, and then the fuel pump pops up creating a leak if you fill the tank.  You really want to correct that first.

https://rivperformance.editboard.com/t10875-rusty-fuel-tank-tab-repair?highlight=rusted+gas+tank


That picture is the air intake temperature sensor. I doubt that is a problem.

BuickRivieraGeorgia wrote:

Also, I got this Actron because I thought it could read live data! Are there better alternatives?

See what the directions actually say. Your video showed you getting codes thrown while the engine is running. You are going to want to see a fuel trim graph, and other graphs. HOwever, you've got enough to fix now, you can worry about tht scanner later.

My snark about K&N was a WAG but turned outto be true. What happens is that some people (that would be you) can over-oil the filters and then when the engine is running a film of oil is deposited on the sensor in the MAF. You may need to replace your maf. A pick n pull junkyard MAF will likely work fine. My current MAF is a pull out of a '96 Camaro.

Also, that fuel problem. The fuel tank is supposed to hold vapors in and accept returns under pressure from the pressurized side of the fuel system. With whatever that gaping hole is in your tank the computer does not know what to do to correctly adjust idle. So yeah it will idle crappy from that *as well as* the MAF problem. Regarding the tank, doing a search you will find repair rings for the tank (try Summit Racing I think). While you are in there you may want to upgrade or replace your fuel pump and replace its filter socks. There are two. You can get them from about any NAPA, they won't look identical but they just need to match up the general size and exactly match the metal fittings on the ones you pull.

And that air temp sensor you've got in your hand by the air cleaner, they are $11 each from rockauto.com... in case your scanner says the intake air temp is some goofty unrealistic number...

@ LARRY70GS
@ albertj

Fixed the Idle problem!
It turns out the geniuses that cleaned my injectors did not tighten the fuel rail bolt all the way and the last injector didn’t have vacuum...

I am planning to do the whole suspension and I will drop the tank as well. I have changed the fuel pump before, so I do have that problem and will fix that up as well - a new lock ring is on its way too.

I think my MAF is gone... it idles at around 1300 when I turn on AC or the heat. I read on another forum that it’s most likely the MAF...
So, I suppose you were right @albertj and I will replace that as well

Thanks for your replies and have a good one

BuickRivieraGeorgia wrote:

@ LARRY70GS
@ albertj

Fixed the Idle problem!
It turns out the geniuses that cleaned my injectors did not tighten the fuel rail bolt all the way and the last injector didn’t have vacuum...

I am planning to do the whole suspension and I will drop the tank as well. I have changed the fuel pump before, so I do have that problem and will fix that up as well - a new lock ring is on its way too.

I think my MAF is gone... it idles at around 1300 when I turn on AC or the heat. I read on another forum that it’s most likely the MAF...
So, I suppose you were right @albertj and I will replace that as well

Thanks for your replies and have a good one

You have a good one, too. YOu're doing fine.