C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Crossfire to single tbi

Thread Tools
 
Search this Thread
 
Old 06-12-2013, 10:29 AM
  #41  
Rohn
Pro
 
Rohn's Avatar
 
Member Since: Jul 2002
Location: Milwaukee Wi
Posts: 703
Likes: 0
Received 0 Likes on 0 Posts

Default

Should I be upgrading to a 7747 ECM even if I keep the stock CFI system?
Only if the car needs tuning. 8746 is a better choice as it has IAT support. Note any swap will need an adapter harness or a HAM board installed(diversifiedcrossfiresolutions. com) as stock CF ECU is an edge card connection.
Old 06-12-2013, 11:01 AM
  #42  
Tom400CFI
Team Owner
Pro Mechanic
 
Tom400CFI's Avatar
 
Member Since: Aug 2004
Location: Park City Utah
Posts: 21,544
Received 3,181 Likes on 2,322 Posts

Default

Originally Posted by jseremba
I did this on Sunday and my idle went to 1500 rpm warm I ended up turning the rear TBI screww down to reduce the idle to 1000 rpm.

What I did not understand is I set the idle speed so that the manometere read 6 inches. Then did the front TBI unit and ultimately end up using the rear TBI unit to reduce the idle speed. Doesn't that mess everything up?
I used the WinAldl software. Interestingly enough it actually smoothed out the car, when connected. Does that mean anything?
It SOUNDS like you had the two TB's synched (at your 6"), but the min. air was too high (both TB's open too far). If you changed the relationship between the two TB's after that, then the TB's are not synched...although I don't think perfect synch is as important as some claim. Once the TB's are synched, you want to use the main throttle stop screw to set min air adjustment.

IDK why the car ran better with WinALDL hooked up.
Old 06-12-2013, 11:51 AM
  #43  
jseremba
Drifting
 
jseremba's Avatar
 
Member Since: Feb 2013
Posts: 1,408
Received 48 Likes on 45 Posts

Default

Originally Posted by Tom400CFI
It SOUNDS like you had the two TB's synched (at your 6"), but the min. air was too high (both TB's open too far). If you changed the relationship between the two TB's after that, then the TB's are not synched...although I don't think perfect synch is as important as some claim. Once the TB's are synched, you want to use the main throttle stop screw to set min air adjustment.

IDK why the car ran better with WinALDL hooked up.
I think that youare correct about the mnimum air. So is that an IAC adjustment. If so how do I make the adjustment?
And do I adjust the IAC and then readjust the TBIs witht the manometer to 6" of water?

Thank you
Old 06-12-2013, 11:56 AM
  #44  
jseremba
Drifting
 
jseremba's Avatar
 
Member Since: Feb 2013
Posts: 1,408
Received 48 Likes on 45 Posts

Default

Originally Posted by Rohn
Only if the car needs tuning. 8746 is a better choice as it has IAT support. Note any swap will need an adapter harness or a HAM board installed(diversifiedcrossfiresolutions. com) as stock CF ECU is an edge card connection.
I think the car can use some tuning. But maybe we are using the wor ina different context. Maybe you should explain what you mean. Then I would know for sure. Secondyl what is IAT. Sorry the acronyms to a newbie like me is very frustrating. looking forward to hearing back from you.
Joe
Old 06-12-2013, 11:59 AM
  #45  
Rohn
Pro
 
Rohn's Avatar
 
Member Since: Jul 2002
Location: Milwaukee Wi
Posts: 703
Likes: 0
Received 0 Likes on 0 Posts

Default

I was refering to chip tuning.

thirdgeneration.org in DIY Prom stickies will explain
Old 06-12-2013, 12:01 PM
  #46  
Rohn
Pro
 
Rohn's Avatar
 
Member Since: Jul 2002
Location: Milwaukee Wi
Posts: 703
Likes: 0
Received 0 Likes on 0 Posts

Default

http://www.crossfireinjection.net/how_to.htm has a write up on "balance"
Old 06-12-2013, 01:16 PM
  #47  
Tom400CFI
Team Owner
Pro Mechanic
 
Tom400CFI's Avatar
 
Member Since: Aug 2004
Location: Park City Utah
Posts: 21,544
Received 3,181 Likes on 2,322 Posts

Default

Originally Posted by jseremba
I think that youare correct about the mnimum air. So is that an IAC adjustment. If so how do I make the adjustment?
And do I adjust the IAC and then readjust the TBIs witht the manometer to 6" of water?

Thank you
Balance the TB's using what ever method you prefer.

Block the IAC passages so no air passes

Adjust the main "throttle stop" screw until you achieve 400 RPM idle speed.

Readjust TPS to ~.5v. Your minimum air is set.

Remove IAC blocks and go drive car above 30 mph to reset IAC motors (if necessary).
Old 06-12-2013, 06:40 PM
  #48  
jseremba
Drifting
 
jseremba's Avatar
 
Member Since: Feb 2013
Posts: 1,408
Received 48 Likes on 45 Posts

Default

Originally Posted by Tom400CFI
Balance the TB's using what ever method you prefer.

Block the IAC passages so no air passes

Adjust the main "throttle stop" screw until you achieve 400 RPM idle speed.

Readjust TPS to ~.5v. Your minimum air is set.

Remove IAC blocks and go drive car above 30 mph to reset IAC motors (if necessary).
Thank you will do on this weekend
Old 06-12-2013, 06:42 PM
  #49  
jseremba
Drifting
 
jseremba's Avatar
 
Member Since: Feb 2013
Posts: 1,408
Received 48 Likes on 45 Posts

Default

Originally Posted by Rohn
I was refering to chip tuning.

thirdgeneration.org in DIY Prom stickies will explain
I will do my assigned homework.
Old 06-12-2013, 06:44 PM
  #50  
jseremba
Drifting
 
jseremba's Avatar
 
Member Since: Feb 2013
Posts: 1,408
Received 48 Likes on 45 Posts

Default

Originally Posted by Rohn
I think I did this one. but I will check to make sure. Thank you
Old 06-16-2013, 04:42 PM
  #51  
jseremba
Drifting
 
jseremba's Avatar
 
Member Since: Feb 2013
Posts: 1,408
Received 48 Likes on 45 Posts

Default

Originally Posted by jseremba
I think I did this one. but I will check to make sure. Thank you
Someone sent me a procedure
turn on car and paper clip between A & B on the OBD1
disconnect the IACS.
Start the car
set idle 400 RPM
Shut car connect IACs
I did this, set the idle at 600, and after I drive the car I was 1500 RPM at idle.
I have changed the CTS, set the TPS to 0.5 volts. Use the Winalsl software. Does anyone have a way of interperting the data?
Old 08-24-2018, 11:40 AM
  #52  
T.j. Driggers
1st Gear
 
T.j. Driggers's Avatar
 
Member Since: Jul 2017
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by joshwiles
I'm not seeing how the IAC would be a problem? I mean yeah, crossfire has two, but they run on the same wires. Plus, you have a base idle already.

Thought I'd go ahead and share what's been done. So I picked up a 1990 K1500 TBI intake from a local junkyard. Removed the old intake and sat the new one in to find that in 87, center intake bolts on the heads were changed to a more straight angle. So I took it back off, and with a drill bit, bore the hole to the correct angle. Then I put the intake back on and tightened it down. Afterwards I hooked everything up to find out that i broke the in-fuel line on the injector pod. So I'm waiting on a new throttle body as we speak. As for the air pump problem, I had already remove it and ran a shorter belt, so no worries there. And for the air filter, I have about an extra 3-4" of clearance because there is a hole in my hood underneath my hoodscoop for fresh air. Anyone want a crossfire intake?
Tps wiring and breather clearance too tps connector is my problem any ideas?
Old 08-24-2018, 04:11 PM
  #53  
cv67
Team Owner
 
cv67's Avatar
 
Member Since: Oct 2004
Location: altered state
Posts: 81,242
Received 3,043 Likes on 2,602 Posts
St. Jude Donor '05

Default

May want to start your own new thread, this one is 5 yrs old. Plenty of CFi guys to help you out.
Old 08-24-2018, 07:00 PM
  #54  
ex-x-fire
Drifting
 
ex-x-fire's Avatar
 
Member Since: Dec 2009
Posts: 1,934
Received 191 Likes on 150 Posts

Default

Originally Posted by T.j. Driggers
Tps wiring and breather clearance too tps connector is my problem any ideas?
Use a 87-89 tbi unit, the tps has the same connector as a crossfire.
Old 08-26-2018, 10:31 PM
  #55  
Fess
1st Gear
 
Fess's Avatar
 
Member Since: Aug 2018
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default 1984 thumper

What mods do I need to change in my stock 84 corvette to install an entry level thumper camshaft? I dont need power, I just want a radical rough idle
Old 08-27-2018, 03:44 PM
  #56  
Tom400CFI
Team Owner
Pro Mechanic
 
Tom400CFI's Avatar
 
Member Since: Aug 2004
Location: Park City Utah
Posts: 21,544
Received 3,181 Likes on 2,322 Posts

Default

Just disconnect a few spark plug wires, retard the timing and open the throttles to compensate....it'll sound radical.
Old 08-27-2018, 04:26 PM
  #57  
corvettenorway
Burning Brakes
 
corvettenorway's Avatar
 
Member Since: Feb 2013
Location: norway
Posts: 1,153
Received 148 Likes on 94 Posts

Default

:d:d:d
Originally Posted by tom400cfi
just disconnect a few spark plug wires, retard the timing and open the throttles to compensate....it'll sound radical.



Quick Reply: Crossfire to single tbi



All times are GMT -4. The time now is 02:31 PM.