I just e-mailed tunercat with the follwing info and will pass it on as soon as they answer me with a possible solution. In the Dec. 2001 issue of Corvette fever in the "wear and tear" column the author talks about a problem that he had after installing an 89 tpi onto an 85. Looks like he pulled his hair out with it and then had a friend that programs (doesn't say who) found a "crank rpm vs. injector pulse width" that had quite different parameters from the codes with a cold start inj. He said that this completely solved the long crank problem. He said that he checked the injectors for elec. when cranking and found that the ecm had a lag of anywhere from 3 to 5 sec. with the problem parameters. It would sure be great if this would do the trick! Makes sense,Yes????? Again I'll post here if tunercat can add this parameter.

------------------
86 406

 

I just got a response from Tunercat-they sent me a new tdf for the 6E with a table- Crank fuel PW multiplier vs. referece pulses. First table is for reference pulse 1 to 16. In arap the first 8 reference pulses are 0. I'll be increasing these values today and will post results. Quick response from Tunercat!!!



------------------
86 406

 

This sounds promising. Is this a new official TDF or a test version?

------------------
'87 IROC 5.7l TPI - original owner!

 

Have you compared the values in this table on other chips yet?

 

I don't know if Tunercat considers it a "test" version or not; however I just asked them about it and they sent it. Their usual great service!!!
afgun- I've only compared it to other 89 codes-they're all the same. I asked Tunercat about comparison to 32B codes-they said it's in the 32B and is different, but didn't say by how much. Now for the best news-I just changed that table to .5 from 0 at multiplier 1 to 8; NO MORE *&%$#* LONG CRANK!!!!! It fires right up! The only thing I have to do now is decrease the crank pulse width vs. coolant temp that I'd kept increasing before, as now it smells rich after starting and tried to stall at first. Hope this helps everyone!!!

------------------
86 406

 

I haven't been following any of this, so I have a few questions:

What do you consider a long crank time?

When I put in the ARAP code on mine, it fired right up.

Is this something that happens when you change from a pre '89 code?

Non crank related question- What version was the $6E TDF you got? I currently have a version T, and wonder if I need to get an update.

Sparks a flyin'

 

The tdf they just sent me is version V. Long crank=3 to 5 sec. Mine is an 86 originally and I'm now running the 89 ARAP; I don't know if other folk that were originally 89 have the same problem.

------------------
86 406

 

My car is an '89 L98, so maybe it doesn't affect it. Going to check with TC to see about getting your version of the TDF.

Thanks,

Sparks a flyin'

------------------
1989 L98 IROCZ, Bored .030 over,400 Crank,Dart PRO 1 Heads 200cc intake,ZZ3/ZZ4 Cam,Crane 1.6 RR,Edelbrock 3860 Hiflo TPI Manifold, AS&M LTRs, Edelbrock 58MM TB, Ported Plenum, TCI Reverse Pat Man Valve Body, SVO 24# injectors,TCI Streetfight Stall Converter, 3.23 Gears on Auburn Pro Posi, Some Suspension Mods

 

On the $32B (and with the cold start injector hooked up) mine fires on the very first revolution of the engine! On $6E code it takes several revolutions before it starts (most of the time). I pull the Crank fuse when running $6E.

ARAP is just one example of $6E code. I am using AUJM as my base image.



------------------
'87 IROC 5.7l TPI - original owner!

 

I e-mailed TunerCat this morning for new TDF's on both $32B and $6E. I received the new files within two hours!. You can't beat that!

I have looked over them for changes and found some very exciting things. Of course there's the Crank PW Multiplier vs Ref Pulse. Man, that looks like the place to fix the long crank time problem! I also like the addition of Initial Spark Advance and TCC Unlock Prevention Speed. I have wanted to change the former, and the latter explains why some of my TCC settings don't seem to work. I wonder how much other great stuff is in there that we don't know about...

However, I can't figure out the distinction between Warm IAC Target RPM and Desired Idle Speed. Any help on that?

------------------
'87 IROC 5.7l TPI - original owner!

 

On the $32B (and with the cold start injector hooked up) mine fires on the very first revolution of the engine! On $6E code it takes several revolutions before it starts (most of the time). I pull the Crank fuse when running $6E.

ARAP is just one example of $6E code. I am using AUJM as my base image
--------------------------------------------
That is all understood, I guess what I was thinking (from what was stated about ARAP causing a long crank time) that maybe the problem was from switching from an earlier ECM code to the $6E and that it wouldn't/didn't happen with mine.

My car initially ran the APYN code, which obviously is another $6E, so that is probably why I didn't notice any difference in the crank time.

Sparks a flyin'

[This message has been edited by sparks383iroc (edited October 17, 2001).]

 

I have been following this topic closely. I am quite interested in that new table that you mentioned. My car usually starts quickly when cold, but I have longer crank times when it is hot, or slightly warm, as in sitting in a store parking lot for a few minutes. I haven't really changed much with my ARAP bin to affect the starting. But I think I had the same problem with my original $32B bins. I am not using my cold start circuit now either, so my "hard starting HOT" may not be PROM related.

PJ, don't you mean the tables "Desired idle speed vs coolant" and "Closed loop IAC target RPM vs coolant"? These seem to be the exact same table!!! The "warm IAC park vs coolant" is a different table. Maybe we should ask TC directly.

------------------
Best ET 14.413 @95.57 without
pulling valve covers or manifolds.
Also with stock 2.77 rear end!!!

 

Yeah, you're right. I got my tables mixed up

I thought those on this board that had hacks of the $6E could shed some light on this. As I've said before, it's only within the context of the code in which they're used that you can make sound decisions regarding what changes to make to the tables. Going by the name (source unknown) of a table isn't very reliable.



------------------
'87 IROC 5.7l TPI - original owner!

 

I too switched to ARAP and hate the long crank. I have been looking for other differences between '88 and '89 - assuming a stock '89 must fire up without delay.
From the description, it sounds as though the stock settings want to wait two revolutions (8 dist ref pulses) before adding any extra crank fuel. Do all 89s take longer to crank than earlier TPIs? If so, why would GM do this?

 

I actually like the longer crank time as I look at it as kinda priming the engine with oil for a second or two before it starts...... It must help a little at getting some oil through the engine before it starts........

------------------
1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

I just switched the first 4 slots to .5 and the following to .25 and the motor fires right up! I was always annoyed by the long crank times but they are history now! I too wonder why GM would do this but it seems to me like it should have been this way all along. Good work whoever found this out(drive it)!

------------------
89 IROC-Z 355 10:1 , AFR 190 heads, LT4 HOT cam w/ 1.6 roller rockers, complete Superram intake, 58mm BBK TB, 24# svo injectors, screens out of MAF, MAT relocated, March underdrive pulleys, Streetdampner, Crane HI-6 ignition, 160 thermostat, K&Ns, TES headers(Jet hot coated), 3" Random Tech cat, Mufflex 4" cat back, B&M shift Kit, 2500 converter, 3.27s, and 4-wheel disc. Chip is custom(doing it myself). 2 1/2 Harwood and just painted.

 

I would also like to offer kudos. Still have a little crank time but not like before.

 

What address was this table located at?
If you tell me, I'll update the Winbin ecu file as well.....

------------------
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

 

When you say 2 revolutions = 8 dist ref pulses, do you mean 2 revs of the motor, or 2 rotations of the dist? I would think motor.

Also why are the multipliers less than 1.0? Seems like that would make the injector pulse width smaller. Maybe you actually divide the PW by the multiplier??

I would think that longer crank times are harder on your electrical system. The sooner that motor gets fired up the better!!

------------------
Best ET 14.413 @95.57 without
pulling valve covers or manifolds.
Also with stock 2.77 rear end!!!

 

I was wondering the same thing. There's already a table for Crank Fuel Pulse Width vs Coolant Temp. Why multiply a multiplier?



------------------
'87 IROC 5.7l TPI - original owner!

 

thanks for the heads up, i have been struggling with that 3 sec crank time and wondeing what was going on... When my car is warm it has no problem firing up though, go fig..

John

 

I'll take the hit on needing a starter once in a while (most likely not any sooner than normal) for the added lifespan of my bearings and internals......

------------------
1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

I've got a couple of questions:

1) Does the extended crank time really give you any oil pressure to protect the bearings and such?

and

2) Could someone post the memory locations and table values which you've found helpful in reducing crank times?

Many thanks,
Craig

 

Well, I doubt it builds any oil pressure, per-say, before the engine starts, but it will start the flow of oil throughout the galleys and passages. Building a reasonable amount of oil pressure would take more than a couple extra seconds of crank time. But just getting the oil through the system will get some oil onto the bearings and such and allow the pressure to build faster when the engine does fire up - and maybe save a little bit of wear on the internals......

Well, that is my theory anyway.......

Laterzzzzzz

------------------
1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

I second that, the location of that table would be very helpful, and I would of course update the Winbin 6E .ecu file if someone told me where it is. Have spent some time comparing the original 6E with the ARAP, given the clue that the first 8 values are supposed to be 0 in the ARAP code.

However, things are not always that easy, the table must be offset, because there in nothing that looks obvious just by doing a quick compare of the bins....

Will dig deeper in this unless someone is kind enough to share the secret of this mysterious table

------------------
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

 

Pulses 1-24(?):
C38B-C3A2

Value in memory location = multiplier * 255 (256,whatever).

For instance, if you want a multiplier of "1", put a "255" in the memory location. If you want a value of "0.5", put in a "128".

Stock ARAP settings have the following:
C38B-C392: 0 (0.0)
C393-C394: 128 (0.5)
C395-C39A: 64 (0.25)
C39B-C3A2: 51 (0.2)

So for the first few cranks, there's no fuel. Then it gives a rich shot for a couple pulses, then leans it back down. Seem right? Nice place here to tailor your startup characteristics.

Does this make sense? In agreement with others? I guess if you wanted to crank up quicker, you might move to do the following:

C38B-C38C: 0 (0.0)
C38D-C38F: 128 (0.5)
C390-C395: 64 (0.25)
C396-C3A2: 51 (0.2)

Anyone corroborate this? It does appear to be the coincident pattern. Please let us know if you get this to work, also if you get the WinBin update.

By the way, this information should be available to anyone through a hex file compare before and after a TC edit. It would be nice to have a full mapping of some of the more useful parameters in the WinBin file.

Regards,
Craig

 

I'll bring a chip and test next time I go to the garage, but the IROC away until spring now, starts getting real cold and soon snow & ice here in Sweden

The Winbin update will be available this afternoon, will post here when I have updated the .ecu file....


------------------
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

 

Okay, here is an update 6E .ecu file for Winbin with all the tables concerning Cranking Fuel PW included. Enjoy!

http://www.area51.org.il/~zaphodb/gmecm/6Ev008.zip

------------------
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

 

There is more to the starting system than just the starter. IE cables, battery, alternator, ignition parts, etc. I beleive that long crank times will take it's toll on all of these. As long as you use a quality oil in your motor, it shouldn't hurt getting it fired up quickly.

Here are some quotes from TC that I got, which should help explain how these new tables work.

"The multiplier is in fact a 0 to 1.0 multiplier that is used to reduce the crank pulse width. I'm sure the crank pulse width calculations are scaled to take this
multiplier into consideration."

"I suspect this multiplier was used mainly to hold off the fuel until they were sure the engine was spinning fast enough to start immediately after fuel was applied. This is done to reduce emissions during start-up which is one the the dirtiest parts of the
emissions test."

"The 0's in the first 8 locations essentially turn off the fuel during this period regardless of the values in the other
table so the engine will crank at least that long before starting. So increasing these values may help you hot restart problem but you may also have to work on the pulse width vs. coolant temp. table."

This is great info, and should clear things up. Kudos to TC!!! They are very helpfull.

------------------
Best ET 14.413 @95.57 without
pulling valve covers or manifolds.
Also with stock 2.77 rear end!!!

 

Yeah, thanks go to TC.

Have any of the DIYers here tried the memlocs with a direct BIN edit or with the WinBin freeware? I'd be interested to know if it works.

 

Do any of you know if a similar crank pulsewidth table exists for the 7730 ecm $8D speed density L98's?? I know my engine takes considerably longer to start when hot versus cold.

 

Will test that this weekend.....

------------------
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

 

Tried it, works great... It's in my car now, with 128's in slots 1 & 2, and a direct taper down to 64 for 4 cycles then 51 for the rest. Feels pretty good.

 

I've been running on a chip with these changes for a few days, now, and have to say, I think the cranking problem has been fixed. The car starts up right away - cool weather or warm. I had almost given up on $6E code because of this! This fix came along just in time.

------------------
'87 IROC 5.7l TPI - original owner!

 

It fixed my long crank time

it turns over maybe 1ce or twice and then it starts, where before it would take 3 to 4 seconds.

John

 

I tried it also this weekend, exactly the same result as for you, turned over twice, fired instantly after 2:nd revolution... And the car has been sitting in winter storage for one month since it last was started....


------------------
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

 

I was sifting this annoying problem, and even from 2001 this still exists. So Thanks and
Props goto everyone for testing and confirming...

I am confident this is a working solution to my problem because Even my $42 Truck (haha not the cost !!) has the same problem.

So If you crank for 1/2 revolution, let sit, with the key still on, then wait 4 seconds, and turn the key again, it fires with first revolution.

THIS IS TRUE ON ALL 1989 Vehicles I have tried it with.
1989 camaro
1989 iroc
1989 sierra classic
1989 suburban

BTW.. where is a great location to find virgin stock BIN files.
I lost my original before I started modding. ANYR CANADA.

 

At least half of those are TBI vehicles. This thread seems to have been about TPI stuff (multiport). I've found that TBIs don't start nearly as fast from cold. The reason that 1/2 crank helps is you're priming the manifold. It's sort of like giving a pump shot or two in a carb car before cranking. I've tried richening my crank AFR, messed with the choke and other settings. Nothing really affects the crank time. The funny part, at least for my car, is that cold start crank time seems to vary quite a bit for the relatively same conditions.

 

The crank PW multiplier didnt start appearing in the tbis untill the PCMs, and in those I dont think it was used, but I could be wrong. The cause is probably the fact that the manifold is dry and in takes some time for the fuel to reach the cylinders with a wet flow system. I just let it crank for the extre two or three seconds.

 

The crank PW multiplier is available in the '7747 $42 code (TBI). As others mention it is that the system needs to have the fuel wet the manifold first, then it reaches the cylinders.

At one time I enabled TPS AE with a non-running engine. Was able to prime up the system and start it right off. When I switched to sync AE I disabled it. In a way I'd like cold starts to catch right off, but then again, does it really matter?

Currently, I crank for about 1/2 second, pause, then crank to start. Works just dandy. Then again, maybe I'll change the code to enable an async injection on a non--running engine so folks can prime it. Just like the 'ole double-pumper. . .

RBob.

 

I think that would be great.

Here's an interesting tidbit. If I pump the gas, I believe I can dump extra fuel into the manifold (AE) during cranking, and this drastically shortens crank time. Is there a way to mimic this fueling without touching the throttle? Obviously opening the throttle also allows extra air flow so it might be complicated. Maybe the extra air just allows the fuel to reach the cylinders faster.

 

Doh... I meant crank PW multiplier vs. DRPs like the tpi cars have. My bad.

I just let mine crank. For whatever reason, the time needed to start was fairly predictable when the engine had been sitting for a long time. It got to the point there I just turned the key for a fixed ammount of time and then reach for the shifter.

As far as the AE goes, I believe its disabled untill the engine has actually started.

 

In the later tbi trucks its actually set up to give a large blob of fuel for the first few DRPs and then it tapers off. The crank fuel delay option is disabled.

 

This might be a stupid question BUT... those of you having a hard time with the cranking, are you coming from an earlier TPI system with the cold start injector? If you are, when running the $6E code, is the cold start injector unplugged? If not, that'll be why you're cranking so long. It'll run really rich with the $6E and cold start hooked up.