Chevelles.com banner

161 - 180 of 2668 Posts

·
Registered
Joined
·
131 Posts
Hello chevelles.com even though I have a mustang this forum has a wealth of knowledge on fitech so I am here asking for help. I have a 351w with stage three track heat heads 8.5 to1 compression, super victor intake, custom cam motion camshaft with .565 lift on 114deg lobe separation (forgot duration) and pt88 turbo. any how I have the typical cold start issue where it will fire then stall but second hit it will stay running. I have selected cam 2 setting because I see 16" vacuum at 850rpm and iac set at 8. From what I have read when you have this issue you need more fuel on prime multi and crank 20f etc. From what I gather the range is -100 to 100 on the settings. When I opened the controller my prime multi is all ready at 259!!!! That's right 259!!! Does this mean I need to step up to cam setting #3. Thanks guys I appreciate the help and sharing of knowledge.
93weezer
With 16" of vacuum at idle I would think your a#2. Make sure your key power source has power in crank position.

On the dashboard screen watch the RPM signal and make sure you have it cranking and run. See if when it false starts you loose the RPM signal.

Larry
 

·
Registered
Joined
·
281 Posts
I'm glad you guys mentioned the decel open IAC. When rpms were coming back to idle it would slowly drift from 1000 down to idle. It was 1.6 from the factory. - 40 decel open iac seems to work for me.it seems more normal now. It's a stick car. Even a chevelle!
 

·
Registered
Joined
·
92 Posts
I'm glad you guys mentioned the decel open IAC. When rpms were coming back to idle it would slowly drift from 1000 down to idle. It was 1.6 from the factory. - 40 decel open iac seems to work for me.it seems more normal now. It's a stick car. Even a chevelle!
Yep -40 a good number for the stick.:thumbsup:

65-StingRay
Wayne
 

·
Registered
Joined
·
92 Posts
93weezer,
just checked my prime fuel multiplier and mine is - 258. I believe it's been this large since the beginning.

65-StingRay
Wayne
 

·
Registered
Joined
·
131 Posts
93weezer,
just checked my prime fuel multiplier and mine is - 258. I believe it's been this large since the beginning.

65-StingRay
Wayne
That's interesting mine is also 259. Here where it gets better if you select edit it tells you the number is not valid. Range is max 199 and min is -100 ?????? I would think the value is not 259 but what is it

Larry
 

·
Registered
Joined
·
39 Posts
I am a Camaro guy, and I think they tolerate me...but a Mustang guy?? :wink2:

In other news, my idle is still jacked. Didn't play with it today, but had to drive it to have some exhaust leaks rewelded. IN 5 o'clock traffic. With the idle fluctuating between 500-1200 (IAC steps from 0-~20), it kinda sucks. I am going to call them tomorrow. My adjustment screws are both out about 1 full turn. I think I may have to take it up some. BTW, my IAC Learn (I think that's what it's called) on the dashboard is at 1 and is still there. Does that mean it is finished learning? Do I need to reset it? How do I do that? Thanks for your (continued) patience guys.
As long as it's fast don't care what it is, if I knew then what I know now it would have a 6.0ls engine in it. Lol
 

·
Registered
Joined
·
39 Posts
Ok finally got a hold of Bryce yesterday at fitech and he said the prime multi at 259 is fine. So that leads me to a couple of questions, the main problem I'm trying to sort out is that on a cold start it will fire on first hit but stall and 2nd hit it fire and stay running. I told him this and he recommendeds I add 10% fuel in the after start cold setting (20f) to start with. Does that sound right? Also for ****s and giggles I inputed the settings from another forum members settings (similar combo) his prime multi was at 51 so I tried it and my car didn't respond well to it. I didn't realize he was at 6000ft altitude and I'm at sea level and now it won't let put it back to 259! How do I reset to start fresh? Can I just disconnect the main power? One more question, sorry guys. Lol. Anyhow if the primary and secondary plates are connected with a 1 to 1 linkage why do you need to adjust both primary and secondary throttle screws?
Thanks guys,
93weezer
 

·
Registered
Joined
·
39 Posts
Ok finally got a hold of Bryce yesterday at fitech and he said the prime multi at 259 is fine. So that leads me to a couple of questions, the main problem I'm trying to sort out is that on a cold start it will fire on first hit but stall and 2nd hit it fire and stay running. I told him this and he recommendeds I add 10% fuel in the after start cold setting (20f) to start with. Does that sound right? Also for ****s and giggles I inputed the settings from another forum members settings (similar combo) his prime multi was at 51 so I tried it and my car didn't respond well to it. I didn't realize he was at 6000ft altitude and I'm at sea level and now it won't let put it back to 259! How do I reset to start fresh? Can I just disconnect the main power? One more question, sorry guys. Lol. Anyhow if the primary and secondary plates are connected with a 1 to 1 linkage why do you need to adjust both primary and secondary throttle screws?
Thanks guys,
93weezer
I also verified constant power, proper ground and good rpm signal (I'm using programmable msd 6530 to control timing and use it for rpm signal).
 

·
Premium Member
2000 Trans Am WS6
Joined
·
5,052 Posts
Discussion Starter #169
Ok finally got a hold of Bryce yesterday at fitech and he said the prime multi at 259 is fine. So that leads me to a couple of questions, the main problem I'm trying to sort out is that on a cold start it will fire on first hit but stall and 2nd hit it fire and stay running. I told him this and he recommendeds I add 10% fuel in the after start cold setting (20f) to start with. Does that sound right? Also for ****s and giggles I inputed the settings from another forum members settings (similar combo) his prime multi was at 51 so I tried it and my car didn't respond well to it. I didn't realize he was at 6000ft altitude and I'm at sea level and now it won't let put it back to 259! How do I reset to start fresh? Can I just disconnect the main power? One more question, sorry guys. Lol. Anyhow if the primary and secondary plates are connected with a 1 to 1 linkage why do you need to adjust both primary and secondary throttle screws?
Thanks guys,
93weezer
Here's a quick play by play from a few pages back, on doing a factory reset.

http://www.chevelles.com/forums/8844817-post71.html

I'd also try adding 10% or more to the AFTERSTART FUEL and WARMUP FUEL in 60* and lower parameters. Afterstart only lasts for a few seconds, where warmup fuel keeps it rich a bit longer.

As for adjusting both screws....there is DEFINITELY some "slop" in these linkages, so you're also trying to keep that at a minimum. That play, or slop, is more than likely why some people have more issues getting the IAC set correctly.

FWIW, I noticed a week or so ago, that even though I try to move each one the same exact amount each time, my linkage was not at 1:1, and the primary was moving a decent amount before moving the secondaries. A random, or even having the same, number of turns in or out really means nothing. I suggest verifying that the linkage moves both butterflies immediately when you move it, and then dial in your IAC. It'll be much easier to do so.

I also highly suggest not getting too consumed with the IAC COUNTS either...My car starts and idles just as well at 0 or well into the 60's.
 

·
Registered
Joined
·
45 Posts
FWIW, I just spoke with Kirk at FiTech. Good conversation.

1) With a 109 lobe separation, I should be on cam setting 4 (I'm on 2 now), which "may" help the idle situation. Too much unburnt fuel in cylinders due to the overlap.....will try. (They don't "recommend" a lobe sep any tighter than 110....really?) By interpolation, I suppose you could say cam setting 4=110 minus, 3=112, 2=114, 1=116+.

2) Use secondary idle adjustment screw to fine tune idle.

3) Stressed checking TPS is at 0 (or below 1.5). I assured him mine always was.

4) said I should be raising idle (screws) with engine running, then shut off so TPS can reset. I don't see what difference it would make by me adjusting with it off, but either way.

5) Asked about heat on FCC. He said if fuel wasn't boiling, it's OK, "How do I know if the fuel is boiling?"...."It won't run very well...". OK. Not very helpful, but sure....

6) He's heard a new manual is in the works, as is a forum, but no idea when available.

7) Not sure if any tech will be on Power Tour to help tune/assist.

He explained what IAC was doing, and I understand that. Weird to me that the computer can't negotiate a 109 lobe sep when the carb could fine though. I'll keep playing with it, mostly by raising the throttle plate screws. Basically, instead of shooting for 800 rpm idle, I am now targeting "the lowest idle possible that is steady".
 

·
Premium Member
2000 Trans Am WS6
Joined
·
5,052 Posts
Discussion Starter #171
FWIW, I just spoke with Kirk at FiTech. Good conversation.

1) With a 109 lobe separation, I should be on cam setting 4 (I'm on 2 now), which "may" help the idle situation. Too much unburnt fuel in cylinders due to the overlap.....will try. (They don't "recommend" a lobe sep any tighter than 110....really?) By interpolation, I suppose you could say cam setting 4=110 minus, 3=112, 2=114, 1=116+.

2) Use secondary idle adjustment screw to fine tune idle.

3) Stressed checking TPS is at 0 (or below 1.5). I assured him mine always was.

4) said I should be raising idle (screws) with engine running, then shut off so TPS can reset. I don't see what difference it would make by me adjusting with it off, but either way.

5) Asked about heat on FCC. He said if fuel wasn't boiling, it's OK, "How do I know if the fuel is boiling?"...."It won't run very well...". OK. Not very helpful, but sure....

6) He's heard a new manual is in the works, as is a forum, but no idea when available.

7) Not sure if any tech will be on Power Tour to help tune/assist.

He explained what IAC was doing, and I understand that. Weird to me that the computer can't negotiate a 109 lobe sep when the carb could fine though. I'll keep playing with it, mostly by raising the throttle plate screws. Basically, instead of shooting for 800 rpm idle, I am now targeting "the lowest idle possible that is steady".
See, this is exactly what pisses me off about FiTech "tech"...different days, different people, different answers...:frown2:

I specifically asked both Bryce, and Ken (FiTech Owner) about my cam specs and their self learning EFI Throtle Body. Both said it would be no problem whatsoever...

I have a hydraulic roller cam with a 107* LSA, and 83 degrees of overlap, I believe it is...and car runs, and idles best on CAM setting #2.

Cold start idle:
https://youtu.be/rUhNncFpgM4

If your fuel is boiling, it'll be doing this:
Engine off, after running for just a few minutes...

https://youtu.be/7oWYO_0PSQE

Or worst scenario:
https://youtu.be/nWjTebvY5gc

Which is why I would never use, or recommend anyone ever use, the Fuel Command Center on any car, ever...regardless of their claims that it is now fixed due to my issues being documented.
 

·
Registered
Joined
·
39 Posts
Here's a quick play by play from a few pages back, on doing a factory reset.

http://www.chevelles.com/forums/8844817-post71.html

I'd also try adding 10% or more to the AFTERSTART FUEL and WARMUP FUEL in 60* and lower parameters. Afterstart only lasts for a few seconds, where warmup fuel keeps it rich a bit longer.

As for adjusting both screws....there is DEFINITELY some "slop" in these linkages, so you're also trying to keep that at a minimum. That play, or slop, is more than likely why some people have more issues getting the IAC set correctly.

FWIW, I noticed a week or so ago, that even though I try to move each one the same exact amount each time, my linkage was not at 1:1, and the primary was moving a decent amount before moving the secondaries. A random, or even having the same, number of turns in or out really means nothing. I suggest verifying that the linkage moves both butterflies immediately when you move it, and then dial in your IAC. It'll be much easier to do so.

I also highly suggest not getting too consumed with the IAC COUNTS either...My car starts and idles just as well at 0 or well into the 60's.
Thanks you very much for your assistance, I will verify the linkage set up.
I have to say that sight has been a real help and I'd be lost. It just seems that from other sites they onlywant to give up the minimum and let you figure it out.
So called "trade secrets "
 

·
Premium Member
2000 Trans Am WS6
Joined
·
5,052 Posts
Discussion Starter #173
Thanks you very much for your assistance, I will verify the linkage set up.
I have to say that sight has been a real help and I'd be lost. It just seems that from other sites they onlywant to give up the minimum and let you figure it out.
So called "trade secrets "
Well, fortunately, or unfortunately, depending on how you look at it...some of us have had to figure this stuff out due to limited conflicting assistance from FiTech...

Fortunately, many of us have either figured stuff out on our own, or did some homework/research and have been 100% willing to share info with one another. Between everyone's input, and the many different problems/questions, it's built us up a pretty darn good data base. That's pretty awesome, IMO. :thumbsup:
 

·
Registered
Joined
·
45 Posts
I made a video. It sucks. Didn't really know what to show on the dashboard so I could get some input. I've turned and turned and turned the throttle screws. I'm about ready to turn them with a BFH. You can barely hear the engine idling up and down....wish you could hear it better. This (idle fluctuation from 500-1200 rpm) is CONSTANT at idle. I reset IAC Learn. I am beside myself.https://youtu.be/RpdfhDDpDhs
 

·
Registered
Joined
·
92 Posts
Bob, agree with everything you said in above posts. :thumbsup:

93Weezer, try adding 12% across the board for the settings that have temp. ranges. Put 12% in these slots. If this is too much cut it back to 10%. Again don't be scared to play with the settings a bit. Drive it - change -drive it some more.

65-StingRay
Wayne
 

·
Registered
Joined
·
14 Posts
79 Camaro guy, Have you just tried richening up the idle mixtures to see if you have a lean surge?
 

·
Registered
Joined
·
131 Posts
Just passing along one of my tech calls about IAC steps. Asked about sec stop screw, was told not to adjust because it is for syncing rear throttle. Mine has no issue with front and rear syncing or wide open throttle plates.

If you think about the rear shaft has a return spring, if you back out rear screw it's going to close and remove slack in the connecting link of the front shaft. Some of you guy's have stated you have a slight delay in the rear opening, maybe that's why. As some have tried to adjust that link and no matter where positioned have play.

So for those adjusting both screws equally I think your doing harm, where if you adjust the front it will move the back if everything is working properly in sync.

Larry
 

·
Registered
Joined
·
131 Posts
I made a video. It sucks. Didn't really know what to show on the dashboard so I could get some input. I've turned and turned and turned the throttle screws. I'm about ready to turn them with a BFH. You can barely hear the engine idling up and down....wish you could hear it better. This (idle fluctuation from 500-1200 rpm) is CONSTANT at idle. I reset IAC Learn. I am beside myself.https://youtu.be/RpdfhDDpDhs
Would like to see your idle A/F, looks like it's spiking lean. See what the target A/F is at idle, maybe lower it by a few points and see.

Also by default the fan controller is enabled. It will change the idle at the set temp I think by 30 rpm, if not using it disable fan

Larry
 

·
Registered
Joined
·
45 Posts
Richening idle mixtures? Assume I do that with the A/F ratio? OK, you guys are wanting me to fatten it up at idle and see if that helps. Will try. I had to look at my Holley to see about where the throttle blades were to set the ones on the EFI. I wish I could set the idle with the computer disconnected sometimes.
 
161 - 180 of 2668 Posts
Top