Running very rich then lean - Miata Turbo Forum -Boost cars, acquire cats.

Welcome to   Members

Engine Performance This section is for discussion on all engine building related questions. KMiata

LinkBack Thread Tools Search this Thread
Old 10-25-2014, 04:11 PM   #1
Thread Starter
Join Date: Oct 2010
Posts: 25
Total Cats: 0
Default Running very rich then lean

I am currently having an issue with running rich AND lean in the fuel curve

My car:
1990 1.6
T25 turbo spiking 14 down to 12psi
Tdr fuel card
Bipes acu
Walbro 190hp pump
Supra 305cc injectors

Here is the story. After installing the kit I went out and tried some pulls on the stock injectors and with all the other parts the same. It pulled smooth but was lean up top. So I figured if I get larger injectors itll put less strain on them. I found a deal on supra 305cc and tried those.

Now I go out and my First pull or two will be smooth but lean. After that the car warms up more and the next pulls will bogg down completely rich 10afr and stay that way until 4k and the. Peg towards full,off the chart lean.

I know I'm using band aids but it's what I had from the old supercharger. I know people once upon made this stuff work so what do you think is the issue? I can't seem to get the issue solved.
karcher is offline   Reply With Quote
Old 10-25-2014, 07:13 PM   #2
Check out my part outs.
iTrader: (26)
thirdgen's Avatar
Join Date: Oct 2007
Location: The coal ridden hills of Pennsylvania
Posts: 5,459
Total Cats: 115

It sounds to me like that's way too much boost to be running on puny 305cc injectors.
I don't want to sound like a dick because I'm sure that you want to be able to run your car in the way it's currently set up, but my good advice would be to sell the aids and get a megasquirt. You don't even need a good megasquirt. A megasquirt 1 on your car would be perfect. Hell, even a parallel ms1 only controlling spark and fuel would be better than the aids. I'd also recommend 460cc injectors.

As a matter of fact, turn your boost down to like 9psi and report back and let us know if it's doing the same thing.
thirdgen is offline   Reply With Quote
Old 10-27-2014, 08:46 PM   #3
Supporting Vendor
iTrader: (31)
Savington's Avatar
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 13,242
Total Cats: 785

You're running 14psi on bandaids, your car runs exactly like everyone here expects it to (i.e. poorly).
Savington is offline   Reply With Quote
Old 10-28-2014, 08:22 AM   #4
iTrader: (9)
sixshooter's Avatar
Join Date: Nov 2008
Location: Tampa, FL
Posts: 13,148
Total Cats: 963

You have pushed way beyond the design parameters of the Powercard and Bipes, which is about 7-8psi on a 2554. They are pretty much un-tune-able anyway. You have exactly what you have and there isn't much you can do about it.

The parable of the rusty bolt:
A man needs to turn a rusty bolt that is somewhat resistant to being turned. It will require a good 6 point socket and a wrench to loosen it without damaging it. A 12 point socket could work without rounding off the edges, but it is stretching it. Vise grips will mar the bolt head and require replacement of the bolt once it is removed, but will likely remove it if he clamps them tight enough and the bolt head doesn't round off.

All the man has is regular slip-joint pliers. He is using the wrong tool for the job. It will be messy and he will end up with damaged parts and a bolt with a stripped head that will not be removed. Him complaining to about the stripped bolt head will make us facepalm and ask why he tried to do it with the incorrect tools in the first place. Him saying he doesn't want to buy sockets and a wrench doesn't make the bolt sympathize and suddenly say "Oh, okay. I'll work with the tools you have chosen and stop fighting you."
sixshooter is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 52 08-28-2016 04:18 AM
Changing from 460cc to flow force 610cc in diypnp 90 Turbo MEGAsquirt 19 10-19-2015 03:23 PM
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 09:30 AM
Got bad Crank Angle Sensor and Random Misfire codes, but runs fine. Greasyman General Miata Chat 2 09-28-2015 10:44 AM
why is my car running like pewp? (tune/datalog) itsMikey MSPNP 3 09-28-2015 06:40 AM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 06:32 AM.