Notices
Series I Trouble Shooting This is the place to learn more about or discuss any issues you're having with your RX-8

Burning too much fuel

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 09-29-2012, 11:18 PM
  #1  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
Burning too much fuel

So I have an 04 with a Greddy turbo with the BNR turbo upgrade. I just recently installed uncapped injectors, all 6 were replaced with injectors that nearly double the output of stock 820cc. I also replaced the ignition coils with a BHR kit with MSD wires.


The problem I am getting is when I start it, it's like it was flooded and smoke bellows out of the back from fuel of course. I understand that the injectors push double the amount of fuel now, but shouldn't the ECU trim the fuel to where it wouldn't be smoking like that. The other problem that doesn't make sense is that when I push down on the throttle I get no response, nothing. It's like the throttle body isn't connected, but I checked the electrical connections to it and they are fine as well as all the vacuum lines.

I am running the stock map with the Cobb AP, would running a different map fix the fuel problem until I can get it tuned? The ecu right now wont compensate at all for how much fuel is being induced? Why would my throttle not respond at all?

Thank you guys for your time and knowledge.
Old 09-29-2012, 11:59 PM
  #2  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
1/you put bigger injectors in the P1 position and didn't change the tune to compensate !!!!! What did you think was going to happen ??
2/what possessed you to put uncapped injectors into P1 in the first place ?



Last edited by Brettus; 09-30-2012 at 12:06 AM.
Old 09-30-2012, 12:10 AM
  #3  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
Originally Posted by Brettus
1/you put bigger injectors in the P1 position and didn't change the tune to compensate !!!!! What did you think was going to happen ??
2/what possessed you to put uncapped injectors into P1 in the first place ?


I thought the tune fairy would take care of it of course. Actually I figured that the stock ecu may have been able to trim it a little, but that's me being naive.
I put uncapped there because I was getting fuel cut and was instructed that upgrading those would take care of it. I did so and this is where it has gotten me.

So on the helpful side, If I took this to a tune shop they could fix it in that state? Is the throttle issue directly related to the no tune?
Old 09-30-2012, 12:22 AM
  #4  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
First thing i would do is put the stock red injectors back in P1 .Alternatively you could put stock CAPPED yellows there ... but only if you can tune for that via the Cobb. Once this is done get back to us with what issues you have . No point trying to solve anything else till you get this right.

Really bad idea putting large uncapped injectors into the position that relies heavily on precise, well atomised fuel delivery and even worse - not getting it scaled correctly!

Originally Posted by jDt!
I put uncapped there because I was getting fuel cut
would need more info on this but your mechanic lead you up the garden path there .

Originally Posted by jDt!

So on the helpful side, If I took this to a tune shop they could fix it in that state?
Not in a month of Sundays

Originally Posted by jDt!
Is the throttle issue directly related to the no tune?
ummmm ... ya think ?

Last edited by Brettus; 09-30-2012 at 12:28 AM.
Old 09-30-2012, 12:29 AM
  #5  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
Originally Posted by Brettus
First thing i would do is put the stock red injectors back in P1 .Alternatively you could put stock CAPPED yellows there ... but only if you can tune for that via the Cobb. Once this is done get back to us with what issues you have . No point trying to solve anything else till you get this right.

Really bad idea putting large uncapped injectors into the position that relies heavily on precise, well atomised fuel delivery and even worse - not getting it scaled correctly!
Ok, Luckily for me I have another set of stock injectors! I will replace the Reds with stock reds. Other than that, anything else I should be doing?

Thanks for your help, I'm living and learning haha........ at my own expense....
Old 09-30-2012, 12:31 AM
  #6  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
First thing I would do is run away (very fast) from the person who is currently advising you


Who is tuning this for you ?
Old 09-30-2012, 12:33 AM
  #7  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
Well that was a one time thing from a so called mechanic. Not the first time a mechanic has screwed me over. So running Stock P1 and uncapped yellows will solve the issue? well, in theory? haha
Old 09-30-2012, 12:42 AM
  #8  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
Originally Posted by jDt!
Well that was a one time thing from a so called mechanic. Not the first time a mechanic has screwed me over. So running Stock P1 and uncapped yellows will solve the issue? well, in theory? haha
I highly doubt it will solve the original issue . Just the new issues you created for yourself
There is nothing wrong with the STOCK injector setup for up to about 300whp -which very few people attain anyway , so your upgrade has not achieved anything except give you a headace.

The original issue could be simply that you are running a turbocharged engine with NO TUNE !!!!!!! Or it could be any one of a thousand other things relating to the set up and installation.
Old 09-30-2012, 12:44 AM
  #9  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
Well all I am trying to do is get it ready to take and get tuned. I just need to finish the steps necessary to be make the car able to be tuned. That is what I am trying to accomplish here.
Old 09-30-2012, 12:50 AM
  #10  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
In that case , I would recommend you fit the stock reds in P1 , The stock yellows in secondary and the uncapped yellows in P2 . That will give you plenty of fuel and make it relatively easy to tune as well .

Then take it in for diagnosis and tuning .
Old 09-30-2012, 12:52 AM
  #11  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
Originally Posted by Brettus
In that case , I would recommend you fit the stock reds in P1 , The stock yellows in secondary and the uncapped yellows in P2 . That will give you plenty of fuel and make it relatively easy to tune as well .

Then take it in for diagnosis and tuning .
Ok great. Thank you for your help, I really do appreciate it.

Looks like I'm going to have a few uncapped injectors for sale.
Old 09-30-2012, 07:55 AM
  #12  
wcs
no agenda
iTrader: (2)
 
wcs's Avatar
 
Join Date: Feb 2005
Location: Ontario
Posts: 5,210
Received 62 Likes on 54 Posts
Wow, what a read.

Don't go into boost either (or less than 125% Calc load), if and when you get it working again.

Until it's tuned.

Thinking about the trim .. I doubt that the ECU could compensate with Trim for such a large increase in fuel... interesting none the less.

Did you install the kit yourself?
Old 09-30-2012, 10:36 AM
  #13  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
No, turbo was installed professionally, which was done quite some time ago. I just recently installed the larger injectors and the ignition coil kit. I know not to go into boost without a tune, I def don't want to damage anything.
Old 10-01-2012, 01:27 AM
  #14  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
Resolved, thanks brettus for your help.

I did what you said with the injectors and then I had misfiring issues so I checked the ignition coils and spark plugs. Plugs were good wires were connected, still had problem so I swapped with the OEM ignition kit and it fixed the misfiring. I don't know what is going on with my BHR ignition kit. Probably bad connect. not sure.
Old 10-01-2012, 01:44 AM
  #15  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
You need the correct dwell for the BHR coils - It is my belief that they are inferior to stock unless the Dwell is changed to suit them .
That said - there was probably another issue as plenty of others run the BHR coils with no issues.
Old 10-01-2012, 01:46 AM
  #16  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
So how can I change the dwell? I can't really take the car to get it tuned with it misfiring.
Old 10-01-2012, 02:04 AM
  #17  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
It sounds more like I have a bad coil. Either that or I didn't get the wire connections connected good enough. I bought the kit second hand, but obviously assumed it was in good order so a bad coil wouldn't be a crazy guess.
Old 10-01-2012, 02:16 AM
  #18  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
Originally Posted by jDt!
Either that or I didn't get the wire connections connected good enough.
This would be my guess . I always triple check the connectors are in properly ....
Old 10-01-2012, 02:19 AM
  #19  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
I quadruple checked, but I may have just mistaken a bad connection for what I thought was good. Now, Having the car tuned with OEM coils then later installing the BHR kit, will that be very problematic? I could just have the tune slightly tweaked to compensate or is that not even necessary?
Old 10-01-2012, 02:21 AM
  #20  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
That depends on if your tuner knows what he is doing


I would rather run on stock coils than BHR coils with the incorrect dwell .....

Last edited by Brettus; 10-01-2012 at 02:25 AM.
Old 10-01-2012, 07:42 AM
  #21  
wcs
no agenda
iTrader: (2)
 
wcs's Avatar
 
Join Date: Feb 2005
Location: Ontario
Posts: 5,210
Received 62 Likes on 54 Posts
Originally Posted by jDt!
Resolved, thanks brettus for your help.

I did what you said with the injectors and then I had misfiring issues so I checked the ignition coils and spark plugs. Plugs were good wires were connected, still had problem so I swapped with the OEM ignition kit and it fixed the misfiring. I don't know what is going on with my BHR ignition kit. Probably bad connect. not sure.
Originally Posted by jDt!
So how can I change the dwell? I can't really take the car to get it tuned with it misfiring.
I'm confused ...
I thought you said you resolved the misfire problem by swapping in the OEM coils?

You could also be experiencing issues if you haven't installed the injectors correctly or have connect the wire harness incorrectly.
Old 10-01-2012, 12:38 PM
  #22  
Registered
Thread Starter
iTrader: (2)
 
jDt!'s Avatar
 
Join Date: May 2009
Posts: 126
Received 0 Likes on 0 Posts
Originally Posted by wcs
I'm confused ...
I thought you said you resolved the misfire problem by swapping in the OEM coils?

You could also be experiencing issues if you haven't installed the injectors correctly or have connect the wire harness incorrectly.

The injectors are causing no problem, I was getting misfire because of the BHR kit being installed so when I replaced that with the OEM coils it fixed the issue, I am just trying to figure out why the BHR kit was causing a misfire.
So to clear things up, the car has no issue right now with OEM coils, but I'm trying to resolve issue with BHR kit so I can use that.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Hunterkelley24
Series I Engine Tuning Forum
14
06-14-2022 08:32 AM
cliffkemp
Series I Trouble Shooting
7
10-03-2015 11:11 PM
urbanvoodoo
RX-8 Discussion
2
09-30-2015 12:41 AM
RotaryMachineRx
RX-8 Parts For Sale/Wanted
1
09-29-2015 10:26 PM
DeltaJ802
RX-8 Discussion
3
09-29-2015 01:20 PM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Burning too much fuel



All times are GMT -5. The time now is 03:28 PM.