Lean Issue

[DWood1969]

I just put my new motor in my 87 GN and I am having a problem with the numbers 1,5,6 cyl runing lean. I noticed when I was triing to break the cam in the tubes on the headers for those cyl where glowing after only about 4 min at 2000 rpm. When I pulled the pluges on those cyl they looked like I had just taken them out of the box, I noticed the same thing on the plugs out of the old motor. I put new 65# injectors in the new motor so I now that it is not the injectors. Everything else electronics wise is the same as the setup on the old motor. Any help would be great, thanks David.

 

[DailyDrifter]

5 and 6 get more air due to them being in the very rear of the intake manifold, some people get the RJC powerplate to distribute the air more evenly. And I belive 1 leans out because it gets less fuel due to it being the last cylinder to recieve fuel in the rail. Anyone else?

 

[SCOOBY DOO]

Is your chip burned for your new 65 lb injectors?

 

[DWood1969]

I have the rjc plate and it has not been changed to the 65 but it is set for the 50# I had before.

 

[TA49-WE4]

Is your chip burned for your new 65 lb injectors?

Thats a good question. Also what is your fuel presure at? You need click on user cp and go to Edit Signature and put in everything that is done to your car so people know what you have so they can help. Do you have a scan tool? If so what are the readings. There are a lot of smart people on here that can help and will help but they are going to need to know everything about your setup.

 

[SCOOBY DOO]

I have the rjc plate and it has not been changed to the 65 but it is set for the 50# I had before.

If your chip has been burned for your old 50 lbs injectors, then you'll have to get it reburned for your 65's.

 

[TA49-WE4]

I have the rjc plate and it has not been changed to the 65 but it is set for the 50# I had before.

Ok well thats a problem. Also did you set the cam sensor with a cam sensor tool? Did you check for vac leaks?

 

[DWood1969]

I can adjust the setting with the Maft Pro just have not done it yet but I would think if that where the issue it would do it more evenly and I did set the cam with a caspers cap but I have not checked for leaks yet.

 

[TA49-WE4]

I can adjust the setting with the Maft Pro just have not done it yet but I would think if that where the issue it would do it more evenly and I did set the cam with a caspers cap but I have not checked for leaks yet.

OK well I don't know anything about a MAf pro but this person does. You need to send a email or pm to turbodave. I sure he will help you. He is very active on this board.

Click on this link: http://www.turbobuick.com/forums/members/turbodave.html

This person also is very active on the board and runs a maf pro

Click on this link: http://www.turbobuick.com/forums/members/turboburick.html

 

[TurboBuRick]

Use the mainscale in the pro to add fuel to the entire tune. It's the same as adjusting fuel pressure. You should be able to add the fuel needed to compensate for the chip.

Did you notice if it went into closed loop? It will make a difference. Once in closed loop, the ecm will try to correct fueling to maintain a afr of 14.7.
Your BLM will then swing giving you a direction to go in. BLM should be 130 give or take 10. If it is pegged one way or the other (90-150) your at the end of the line. 90 would be running to rich and 150 would be too lean. You can add or subtract fuel with the pro to get this number in range.

Hope this helps.

Rick

 

[DWood1969]

I understand the adding fuel for the whole system but there will still be a rich-lean diference between the cylinders.

 

[TurboBuRick]

I don't think you can really determine that based on the plugs after a cam break in. What you describe is not uncommon.

What was the actual AFR?

Did the ECM go into closed loop? If so, where was the BLM's?

Did you add any fuel with the Pro?

Rick