Cold / Warm Start Ups - Stage I

[flipmo]

Hi guys. I need some advice on a "Very Minor Issue." I'm more of a perfectionist when it comes to these cars and want everything just right; however, if it can't be 100% and I have to live with 99.99%, then I will.

My problem is startup after the car has reached normal operating temperature. Again, I'm having absolutely no problem at all with the car other than the car wants me to "tap the gas pedal just slightly" in order for it to start after it has fully warmed up. During all my initial startups (cold starts), the car cranks right up without me having to press the gas pedal. I mean everytime during initial starts, it fires right up. After running and getting warm, it still starts right up with no problem, but I have to slightly tap the gas. Is this common, guys? Could it be a sensor issue?

Can anyone explain what could be going on here? I'm running the F.A.S.T. B2B system and everything looks O.K. with it. Cars runs absolutely great and I definitely don't wont to change the wrong thing, if it's indeed a minor tuning issue associated with the "Cranking Parameters" in F.A.S.T.

Help

Thanks

flip

 

[ChrisCairns]

I had a similar problem and here's what fixed mine.

Go to idle speed---then Start IAC position vs Coolant Temp and increase the IAC starting point at the higher temp.

 

[flipmo]

I had a similar problem and here's what fixed mine.

Go to idle speed---then Start IAC position vs Coolant Temp and increase the IAC starting point at the higher temp.

Hey thanks for quick response. Here's my current setting within the "Start IAC Position vs Coolant Temp" parameter on my laptop. I'm providing my "Actual Coolant Temp (F) and IAC Position within this section of F.A.S.T.

At 16(F)/IAC Position is 130
At 39(F)/IAC Position is 130
At 61(F)/IAC Position is 130
At 84(F)/IAC Position is 112
At 110(F)/IAC Position is 92
At 140(F)/IAC Position is 82
At 181(F)/IAC Position is 82
At 254(F)/IAC Position is 82

O.K. since my GN wants a slight tap of the gas pedal to start after warm-up, which Degree(F)/IAC Position should probably be changed and by how much.

I hate to mess w/sensitive parts of the system, especially starting and idling parameters; however, I'm willing to take a chance in order to get it to start correctly, both cold and hot. I've had several GNs w/F.A.S.T. but never a starting issue after warm-up (though some would say I don't have an issue at all). I'm optimistic we'll figure this minor issue out.

Thanks guys and please let me know what you think

flip

 

[ChrisCairns]

My understanding of that particular parameter is that it forces higher counts of the IAC, hence the motor is given more air. Kinda like giving it more throttle. In other words it revs up more on the start but then immediately lowers the revs upon starting. That would be controlled by decay I believe.

You won't hurt anything by increasing it...write down the old number (what you quoted here) and then you can always return it to what it was if it doesn't help.

Personally I'd increase everything to 130 if it starts fine with the 130 counts at lower temps. And if that works fine you can always start to lower the counts a bit at a time until you find what it likes.

I play with mine all the time because I like doing it....lol. But I sometimes I don't write down the old numbers or I change a lot of things at the same time....not good.

 

[flipmo]

My understanding of that particular parameter is that it forces higher counts of the IAC, hence the motor is given more air. Kinda like giving it more throttle. In other words it revs up more on the start but then immediately lowers the revs upon starting. That would be controlled by decay I believe.

You won't hurt anything by increasing it...write down the old number (what you quoted here) and then you can always return it to what it was if it doesn't help.

Personally I'd increase everything to 130 if it starts fine with the 130 counts at lower temps. And if that works fine you can always start to lower the counts a bit at a time until you find what it likes.

I play with mine all the time because I like doing it....lol. But I sometimes I don't write down the old numbers or I change a lot of things at the same time....not good.

Hey, Hey. Exactly what I needed to do. I simply increased the following two areas (At 140(F)/IAC Position is 82 and At 181(F)/IAC Position is 82) both from 82 to 87 IAC Position and left everything else alone and that did it. It starts up everytime now without having to tap the gas. It starts up and then idles down pretty smoothly also. My car never gets above 180 ever anyway, so I didn't care about the final IAC position. That's why I love the hell out of this site.

Thanks A Lot

flip

 

[Hot Air]

I agree...you guys are the greatest.
Conrad

 

[turbo2nr]

I also have 83lb injectors, and your car sounds like mine did untill recently. What is your timing around the idle cells? (I'm no expert, just curious.)

 

[flipmo]

I also have 83lb injectors, and your car sounds like mine did untill recently. What is your timing around the idle cells? (I'm no expert, just curious.)

Hi Turbo2nr. How's it going? Timing at idle for me, hmmmm not really sure. I'll have to check F.A.S.T. tomorrow in order to make sure.

What do you mean by "Until Recently." What did you do? My GN is screaming for me to run it down the 1/4; however, I just hadn't had a chance to run it hard yet. I'm hoping for somewhere in the low 10's without having to run high boost.

So I've been told that I do have the parts. We'll see.

I'll Hollow

flip

 

[turbo2nr]

I looked at most other cars in my driveway with a scanner. I found that my other turbo cars from the factory have around 17degrees of timing at idle and it goes up/down around 3 degrees while trying to maintain idle. So I went into the timing correction table in the idle functions and allowed 3 degrees there, and pulled my timing down to around 16 at idle cells(I have no EGR so I dropped it another degree)

I tried to get my car around 12.5 A/F at idle with the A/C on and in drive, warmed up, playing with the VE tables ideling in open loop. Then looked at my IAC.

Should our starting IAC number be about 150% of the idle IAC?

That's where I'm at.

My car was too rich at idle. I forgot what the timing was, I think it was too high. I have the original tune here, I'll check.

I've been chicken to run my new combo. I can't wait, but part of me says hold off. I'm looking for some mid-low 10s also, or broken parts. LOL

 

[turbo2nr]

Yup, just checked. My timing was set at 33 degrees at idle. WAAAY TOOO much. I bet the same guy made your tune. Drives a mellon maybe?
My car idled like poo and I had spent a few weeks getting to know my car and how to start a new tune from scratch. Spent hours looking at my wifes turbo car's timing tables while driving around town. I realize that is not a TR, but good info anyway. Same compression ratio.

 

[turbo2nr]

Of course, right off idle, the timing jumps up. Do you have the FAST tuning video? It's pretty good. Cotton sells them.

I think I remember the starting IAC number should be around 150% of the idle IAC for that particular coolent temp. So you watch the IAC as your car warmes up, and note that curve, then go into the start-up/vs IAC and make about the same curve, only add 50%.

(I need to watch that section again to be sure about that.)

 

[flipmo]

Of course, right off idle, the timing jumps up. Do you have the FAST tuning video? It's pretty good. Cotton sells them.

I think I remember the starting IAC number should be around 150% of the idle IAC for that particular coolent temp. So you watch the IAC as your car warmes up, and note that curve, then go into the start-up/vs IAC and make about the same curve, only add 50%.

(I need to watch that section again to be sure about that.)

What's up man? I checked and before I edited my last post I was correct regarding my idle assumptions. My idle jumps between 31-33 degrees at idle; however, I am having absolutely no problems at all and refuse to screw with anything. I am getting absolutely no idle hesitation, no stalls, no misses, or any idling up and down and the car hauls ass. If your in the MD/NJ area, yes I'm sure the same guy tuned our cars. My idle A/F is around 13.5 - 14.0 on average and I'm getting no gas smells or leaks. Even with the A/C blowing cold I'm having no idling issues while it blows cold on levels 1, 2 and 3 (I never put it on 4 - Just me).

Actually, my car is running so good that I simply check all the numbers everytime I go for a spin and just leave everything alone; however, that's really dependent on the weather and if I want to run more boost also.

I'm not tooooo techy with the F.A.S.T. but I can get in there and tinker with the basics in order to get it to run pretty good. Sounds like the F.A.S.T. video is pretty good to have. I'm going to ask COTTON about it tomorrow.

I'll Hollow (Stop Making So Many Changes and Let's Race - LOL)

flip

 

[turbo2nr]

Are you going to th3 southern T6p track rental on the 8th of Oct? Pig pick'n and both lanes open!

Don't listen to me. I'm a newbie just goofing off. 12.5 A/F at idle is a little rich, but my car does not like it much leaner. I shoot for 14-14.5 just up from idle. I don't know if that is right or not. I'm also in open loop at idle, I guess most of us are.

My car runs good and does not stall so I'm happy. I feel it is safe for pump gas, with a sharp dip in timing and a rise in fuel if I do hit higher boost by mistake.

 

[flipmo]

Are you going to th3 southern T6p track rental on the 8th of Oct? Pig pick'n and both lanes open!

Where's this? I would like to if my scheduling doesn't conflict.

Location?

Thanks

 

[turbo2nr]

Oh, I see you are in Ohio, but hey, maybe you're nutz. http://www.t6p.com/forums/showthread.php?t=14366
www.rockinghamdragway.com

 

[flipmo]

Oh, I see you are in Ohio, but hey, maybe you're nutz. http://www.t6p.com/forums/showthread.php?t=14366
www.rockinghamdragway.com

Damn, sounds like fun brother. Well, 700 miles to race a couple of hours is interesting; however, 10-cylinder ford truck will burn toooo much gas man.

We had some great times last year w/track rentals. Last year when I was in MD, we had a great time the day they rented Maryland International Raceway for a day. Great turnout also with a lot of match races and trash talking - Fun, Fun, Fun!! I was running 11.05s to 11.10s all day that day and was pissed off I never broke 10s w/basic bolt-ons. I went back to the same track that next Friday and put in some C16 instead of 100LL and while it was much cooler at night, ran 10.85 to 10.95 all day. I'm still pissed off about that because I got ragged on during track rentals that day because I couldn't break 10s and did it the next Friday. Damn Grand National competitors .

I wish the same trash talkers would try me today w/my new ride. Bring it on (Not you Bill, Cotton, etc).

Please take PICs and post them when you guys finish. Turn up the "BOOST"

flip

 

[EightSecV6]

If your in the MD/NJ area, yes I'm sure the same guy tuned our cars. My idle A/F is around 13.5 - 14.0 on average and I'm getting no gas smells or leaks. flip

I tuned yours Tony (as long as nothing changed after I sold it and I doubt it did!). Your A/F will appear more rich at low speeds than something with a milder cam due to overlap.Keeping the timing where it is will prevent the engine from "hunting" at idle. Due to changes in atmosphere, you may have to tweak it a little here or there but I wouldnt suspect it would need much! Call me if you need any assistance.

 

[flipmo]

I tuned yours Tony (as long as nothing changed after I sold it and I doubt it did!). Your A/F will appear more rich at low speeds than something with a milder cam due to overlap.Keeping the timing where it is will prevent the engine from "hunting" at idle. Due to changes in atmosphere, you may have to tweak it a little here or there but I wouldnt suspect it would need much! Call me if you need any assistance.

Hey thanks Bill. So far, things are "Gr8" with the car. Haven't had any issues at all. Probably because I baby the hell out of. I know, I know, I know, many guys are saying why in the hell would you baby a Staged car, right?

Just me man. I plan on keeping this one for a minute or two. Hell, you've worked on and tuned just about all the others I've had anyway. Isn't it time for a discount man?

Thanks Again

Tony

 

[EightSecV6]

Hey thanks Bill. So far, things are "Gr8" with the car. Haven't had any issues at all. Probably because I baby the hell out of. I know, I know, I know, many guys are saying why in the hell would you baby a Staged car, right?

Just me man. I plan on keeping this one for a minute or two. Hell, you've worked on and tuned just about all the others I've had anyway. Isn't it time for a discount man?

Thanks Again

Tony

you wanna really feel it "pull"? Get on a nice stretch somewhere and as soon as it shifts to 3rd, hit the converter lockup,hang on! I'd surely give you a discount but last I remember, the car didnt need a thing!I doubt you'd be able to sell that one for an "upgrade" :biggrin: