My car wants to die whenever I put it in gear(auto). The car stutters and the idle drops to 400 which sometimes causes it to die. I was wondering if it was because my timing was too advanced. Could the stall spark feature in the 6E bin help me?

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355 10:1 , AFR 190 heads, LT4 HOT cam w/ 1.6 roller rockers, complete Superram intake, 58mm BBK TB, 24# injectors, screens out of MAF, MAT relocated, March underdrive pulleys, Streetdampner, Crane HI-6 ignition, 160 thermostat, K&Ns, TES headers(Jet hot coated), Mufflex 4' cat back, B&M shift Kit, 2500 converter, and 3.27s.

 

Yes, the spark advance affects how well your engine idles. You might not have enough advance. What is your total advance at idle? You might be maxing out your IAC motor. If so, then the stall saver feature won't work or work nearly as well. What is your IAC count in Park, both when cold and when warmed up?

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Greg Westphal
'87 IROC 305TPI/A4

 

I'll check on my iac counts later. I'm going to try taking timing out all around and seeing if thats better. I dont even know if I can read the iac steps with the scanner software that I have. What's a good starting point for an aluminum-headed motor that idles at 850-900 RPM?

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355 10:1 , AFR 190 heads, LT4 HOT cam w/ 1.6 roller rockers, complete Superram intake, 58mm BBK TB, 24# injectors, screens out of MAF, MAT relocated, March underdrive pulleys, Streetdampner, Crane HI-6 ignition, 160 thermostat, K&Ns, TES headers(Jet hot coated), Mufflex 4' cat back, B&M shift Kit, 2500 converter, and 3.27s.

 

I'd say start at 20deg and add more as required.

EDIT: I do NOT mean 20deg initial advance when setting your distributor! Imean 20 degrees of actual advance when your engine is idling.

[This message has been edited by FastBroker (edited April 02, 2001).]

 

Yep, closed loop, fully warmed up, low 20s is a good starting point. 8 degrees inital and EST connector plugged in.

IAC counts should be less that 25 too. TPS voltage of .61 works best for me.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

1. How do the IAC steps count effect idle?
2. What would be the cons of filling in the cool compensation spark table with 0s. The only reason I would do it would be to rule out variables in the spark table.

Also to anybody out there with aluminum heads, what do your spark tables look like?


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355 10:1 , AFR 190 heads, LT4 HOT cam w/ 1.6 roller rockers, complete Superram intake, 58mm BBK TB, 24# injectors, screens out of MAF, MAT relocated, March underdrive pulleys, Streetdampner, Crane HI-6 ignition, 160 thermostat, K&Ns, TES headers(Jet hot coated), Mufflex 4' cat back, B&M shift Kit, 2500 converter, and 3.27s.

 

Might try starting all over but with the MAF screens in.
Also, might need a 800 rpm idle speed.

If you have a MAF car just use the 6E, it'e the best of the group

 

I found the IAC Step Counts Vs Coolant Temp helped get my engine to the desired IAC position when you are stopping and going to be idleing.

I found that my IAC Step counts were a bit low initially and that I would begin idling at a relatively slower engine rpm than I had specified for my "desired engine rpm". As I waited the IACs would increase and so would my "desired engine rpm" along with the smoothness of the idle.

I just reviewed some of my Diacom readings and noted the IAC level at various Engine Temperatures and adjusted the IAC step counts vs Coolant Temp accordingly. Now, when I slow down the car to an idle, it immediately goes to the proper engine speed and idles very smoothly. Also, my IAC Step counts are almost always remaining where they were set in the table. The ecm does very little adjusting now to the IAC step counts.

It is also worthwhile to look at the min IAC values for "Stay Alive".

[This message has been edited by Glenn91L98GTA (edited April 05, 2001).]

 

Glenn I dont have the "stay alive" table that you are referring to. Maybe thats just with the SD. However maybe adding some steps to the IAC is the answer. Maybe my throttle blades are not opened far enough causing my IAC to have to really open all the way up when I put the car in gear.

Grumpy, I have the idle set high(Ive tried both 850 and 900) and it still does this.
Im starting to think that it is not spark related and may have something to do with the IAC and/or the base idle speed (which is hard to set on a car with a cam, heads, etc because unlike stock I dont think this thing can idle that low)

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355 10:1 , AFR 190 heads, LT4 HOT cam w/ 1.6 roller rockers, complete Superram intake, 58mm BBK TB, 24# injectors, screens out of MAF, MAT relocated, March underdrive pulleys, Streetdampner, Crane HI-6 ignition, 160 thermostat, K&Ns, TES headers(Jet hot coated), Mufflex 4' cat back, B&M shift Kit, 2500 converter, and 3.27s.

 

Well, let me chip in some, I might be of some help.
I have a CompCam Xtreme Energy cam which specs out to 230-236* duration, 510-520" lift and a 110 LSA. I think it's a pretty big cam for a TPI with stock ECM. Well, the car idles at 650-700 RPMs at idle, and a bit lower than that in gear. I have a Hypertech chip and the car never dies on me. I know this is a bit out of the chip subject, but a new distributor will do wonders for a rough running engine. I bought a Proform distributor from Jeg's, put it in and set the thing by just listening to the engine (damper was bad, couldn't set timing right) and the car ran stronger than ever before and the idle had smoothed out considerably. Many thirgenners still have stock distributor and wear and tear plays a major part in a smooth idle. Something to think of.
Rick


ps: don't buy the Proform distributor, it performed superbly, BUT it has a major flaw. The base where the Dist. cap sits on will come loose after a few cooling and heating cycles and this will obviously throw your timing and whatnot off. I had to settle for a Autozone distributor, for now.