LeeH

iTrader: (2)

I have been going up the wall with this issue. Mods are in sig, and there are a lot of them. I have been having a hard time trying to get the idle smooth, and have burned 20+ chips trying to get it right but I have had no success. I have set the stall saver spark enable thresholds 1 through 3 to 350, 450 and 550, adjusted the desired idle speed vs coolant to 700 RPM across the board,
set the EGR on TPS to 99.6% (max value in tunercat), since my egr is non functioning.

The thing idles in drive fairly smoothly at 700 RPM, then it just dies. No warning, no stumble, no codes, nada.

Everything else is great - pulls strong to 6200 RPM, mileage is decent. I wont have access to a scanner for a couple of more days, so I can't pull any data off of the computer, but there are no codes present.
The bin is located at
www.havemann.com/lee/bins/arap070801.bin in case some kind soul takes pity on me and takes a look at it.

(The address is http://www.havemann.com/lee/bins/arap070801.bin - for some reason the while href is screwing up - damn Netscape!)

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www.havemann.com/lee/firebird.html
1989 Firebird Formula, WS6 Package
ZZ4 Crate engine, Accel 24 pound injectors, Accel Superram intake, Accel Large tube runners
SLP 58 mm throttlebody, Edelbrock TES headers, SLP 3" SS exhaust, Random Tech 3" hi flow cat
700R4 trans w/ vette 2/4 shift servo, worked valve body, kevlar band, 2200 rpm stall converter
Borg Warner 9 bolt rear (full poly mounts) Hotchiss panhard rod, Lakewood LCA's, Spohn subframe connectors,
custom chip, Walbro hi-flow fuel pump, Accell HEI billet distributor.



[This message has been edited by LeeH (edited July 10, 2001).]

Grumpy

This page can not be displayed, is all I get

GregWestphal

iTrader: (1)

Go to: http://www.havemann.com/lee/bins/ and then click on the bin to save it.

You have the EGR off %TPS set at 0%, so you might want to raise that to 99.6% also. You have 24# injectors in your sig, but you're still telling the ECM that you have 22# injectors. That's all I could find. If the first one doesn't fix it, then you might have an electrical problem.

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Greg Westphal
'87 IROC 355TPI/A4

LeeH

iTrader: (2)

I fixed the URL...

I set the injector flow rate back to 22.4 because I suspected that the ecm could not keep a decent idle with the higher poundage injector constant. The pulse rate at 24 #/HR may not be letting enough fuel into the cylinders to maintain idle at 650 -700 RPM.
I compensated for this by backing my fuel pressure down to 47 PSI.

This change does eliminate the stalling, but produces an extremely lumpy idle - it sounds like I have a very large cam installed in there.

I will set the EGR off % to 99.6 and see if this helps, but I need to put the scanner on there to check and see if EGR functions are really disabled.

Grim Reaper

Lee, just to warn you. Modifying fuel pressure has its greatest effect at high load/low vacuum like WOT than at low load/high vacuum like Idle. It is not linear or flat, like modifying the Injector Size. It is more like a curved line increasing as the load increases/vacuum decreases.

Take a look at your IAC. (Idle Speed IAC Steps vs Coolant). This table is not defined in the basic 8D.TDFs and most likely not defined in the 6E.TFDs. I just defined it using TunerCat's TDF Editor. But I found it is really important in getting a smooth and constant idle.

Also, if you are using a T-stat other than the stock T-stat, you should look at alterning the IAC Learn values. Even a 180* T-stat is enough to cause the IAC Learn to cease functioning.

LeeH

iTrader: (2)

Glenn -

I see your point - at idle, there is enough vacuum to keep the fpr engaged and keep the pressure at 43 PSI. WOT has the effect of decreasing vacuum, inversely increasing pressure. Still need the scanner to adjust properly...

I have two controls for IAC; one is for steps, and the other is for RPM (see pics below). I never thought of these, but I am still new to this . Any suggestions as to which one to (carefully) modify?

And, as a matter of fact, I am using a 180 thermo, but I don't see anything about IAC learn values. Where would I find these?

Thanks - you have already given me some extremely helpful pointers!


I have this in the 6E version R def file:



[This message has been edited by LeeH (edited July 10, 2001).]

GregWestphal

iTrader: (1)

Hmmmm, you stated in your original message that you had "adjusted the desired idle speed vs coolant to 700 RPM across the board", but the left-side table doesn't show that. The right-side table is only telling the IAC motor where to park when the engine is turned off vs. coolant temp.

I don't recall seeing an IAC steps vs. coolant temp table in the $6E code, nor does the thermostat temperature affect the IAC learn function in the $6E code, at least not with a 160-degree 'stat.

Also, once you get a hold of a scan tool, I'd verify the accuracy of your tach. If you're commanding the engine to idle at 575 rpm in drive when it's warmed up and the tach is saying 700 rpm, then either you have a vaccum leak and the IAC motor is fully closed, or the tach is off. Mine is off by 50 rpm at idle, indicating 700 rpm while the engine is actually at 750 rpm.

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Greg Westphal
'87 IROC 355TPI/A4

Grim Reaper

Lee, neither of those tables are the correct one. You will have to add it yourself using TunerCat's TDF Editor.

The table can be found at location x'C52E to x'C53E on the $6E. I had to define it within the 8D as it was not defined there either.

Its a very useful table IMO and needs to be looked at for controlling the idle.

Also, IAC Learn based on Coolant Temp. It is also not defined, but you can define with TunerCat's TDF Editor.

TunerCat's TDF Editor is a great piece of software for modifying stock TDFs to include constants and tables not defined. It is available on a 30 day free trial. I liked it so much, I bought it. It's a "tuner's dream" come true.

I recommend that if you do start defining your own constants and tables, that you put them in a separate TDF file. This way, if TunerCat releases a new TDF, you can just get the new TDF and not have to re-do everything. Also, if you think it is useful, pass it on to TunerCat. This is often how revisions to existing TDFs are made; when us guys "in the trenches" find a useful constant or table that is not defined, we then let TunerCat know about them so they can include them in future TDFs so we all benefit from the discovery.

[This message has been edited by Glenn91L98GTA (edited July 10, 2001).]

LeeH

iTrader: (2)

GregWestphal wrote:
Hmmmm, you stated in your original message that you had "adjusted the desired idle speed vs coolant to 700 RPM across the board", but the left-side table doesn't show that. The right-side table is only telling the IAC motor where to park when the engine is turned off vs. coolant temp.

This is from a stock ARAP bin - I should have used my modded one for a clearer example. You are right, though. I did modify the closed loop target table.

I should get my (actually my friend's) scanner back tomorrow so I can check the accuracy of my tach anyway...

Glenn -

If I get a chance tonight I will incorporate the TDF editor into my bag of tools. I have never used it, so I can expect some learning curve. Any idea of the address for the IAC learn as well?

Thanks again for the pointers guys!

GregWestphal

iTrader: (1)

You might want to check that again Glenn, since the left-side table is the one you defined. I don't think the '165 ECM has any IAC Learn capabilities like the '730, just the tables Lee pointed out as a bunch of variables to define the IAC's actions.

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Greg Westphal
'87 IROC 355TPI/A4

leirch

Actually, the left table is one that is already pre-defined in the TunerCat TDF. I have that TDF and I also have Glenn's "special" TDF from TunerCat, both for the 6E and 8D masks.
The table Glenn is speaking of is the "IAC idle steps vs coolant"(I think that is the name of it).

Brendan

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1987 IROC-Z L98,SR,EB 6085's,LPE 219/219 SR Cam, Crane 1.6RR, EB TPI Base, 58mm TB, ADS 24#, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, Aluminum DS, 94 Disk Rear, Adjustable Prop Valve, Precision 3.73 Gears, Weld in Sub-Frame Connectors, Hotchkis LCA's, KYB Shocks/Struts, Poly Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm, Big stereo, 730SD Conversion.

To see the ROC, Check out the webpage Here

Grim Reaper

Greg, that is the Idle Speed (yes I remember adding that too). The table I am referring is the actual Idle Speed IAC Step Counts. That is a table that has various IAC Step Counts for a given coolant temperature. The other table shown on the right is the number of "cells" or steps that are stored IIRC. It is not the actual "number of steps" at a certain coolant level, which the ecm learns from. This number corresponds to the IAC# you will see when idling at certain coolant temperatures.

The address I reference is the proper one.

GregWestphal

iTrader: (1)

I still haven't found anything referencing the IAC steps vs. coolant temp. Trust me, it's not there. I've had IAC steps at various coolant temps from 160 to 10, depending on if it was before or after I had set my minimum IAC properly to compensate for the higher-than-stock idle speed. As much as I hate to say this, the '165 just isn't as sophisticated at the '730.

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Greg Westphal
'87 IROC 355TPI/A4

Grim Reaper

You will need to add the table. It is in the address that I already mentioned. I had to add a similar table for the 8D.

LeeH

iTrader: (2)

I have been working some long hours these last couple of days, so I haven't made any progress on this issue, but read below:


Here is an interesting twist, and I would like to get your take on this.

My neighbor the Snap On dude, has been following my progress on this idle issue and has been asking some questions at the shops he visits. One shop which does extensive FI modifications told him that the camshaft in the ZZ4 is made for carbed engines, and will not work well in a batch fire fuel injection engine. I didn't get all the details, cause he only stopped by for a minute last night, but he was told that the intake duration was a problem on this cam, and that I should use a cam like the one I have listed below. He said that that cam was designed for FI'ed cars and would make my idle smooth right out. Anybody out there knowledgable enough to be able to confirm or deny this?

Ramjet 350 / 350 HP FI engine:
GM Part # 14097395 (Roller Tappet)
Lift: .431" Int., .460" Exh.
Camshaft Duration @ .050"
196° Int., 207° Exh.


ZZ4 Engine cam:
Lift .474" I, .510" E
Camshaft Duration @ .050"
208° Intake, .221° Exhaust


[This message has been edited by LeeH (edited July 13, 2001).]

ZaphodB

Isn't $C53E out-of-bounds as the '7165 code is only $4000 bytes in size, $0000-$3fff???

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ZaphodB a.k.a Carl Andersson - zaphodb@faxancruisers.org
'89 Camaro IROC-Z 5.7L TPI - Mods under construction :-)
Custom ARAP Chip Under Development/180 t-stat, Edelbrock TES Headers,
SLP Airfoil, K&N Filters, Accel 8mm wires, Relocated MAT, AFPR @ 45 PSI

Brent

iTrader: (1)

That's a bunch of baloney. Lots of folks are running bigger cams than the ZZ4.

Grim Reaper

No, the ACTUAL starting address for a 165 ecm is x'C000-x'FFFF. Only in the BIN are you seeing the address range x'0000-x'3FFF, but in reality is offset by x'C000. Just like the SD $8D is offset by x'8000 and begins at x'8000.