Wankel7

Back from the dead!

What was the fix for the hesitation problem?

James

Silver7

I would like to bring this thread back to see if anyone has had any luck with this stumbling problem. I still have not gotten rid of this problem completely. I have minimized it by lowering my fuel pressure to 40 psi from 45 psi and messed with tuning just before and after the staging bar and changed my primary injectors to 72lb low impedence

Since I've installed my haltech a few years ago I have done two other installations for two of my friends. Both cars have stock turbos. One car experiences the exact same stumbling problem that mine does. He is running 550/1600 injector combo. The other car does not stumble at all. He still has stock fuel system. I'm pretty sure this problem is car dependent since a lot of haltechs have been installed and not all of these cars experience stumbling. I just need to find out what the difference is between the cars that don't stumble and the car that stumble. Does anyone have any new info regarding this topic that they would like to share?

jacobcartmill

iTrader: (6)

fwiw, i have 550 primaries and 1680 secondaries and all i did was leaned out the FIRST bar AFTER the stage and it went away. however, coming DOWN from boost it seems to stumble noticably, i'm not sure why... anyone have this problem?

billzrx7

mine does it anytime im in boost, i can never give it full throttle

raven bc

I've got 550/1600 and I don't have any stumble at all. The bars right after the cut-off are rich though. If you did the math calculations to figure out where they should be it's way higher. The real reason for it is atomization. When you first go onto boost at lower RPM's the amount of fuel coming out of the 1600cc inj doesn't atomize well because it's a small burst and you don't have the intake velocity. To compensate you run a longer burst.

Raven

RETed

One question...

Where is the staging bar set at???

One hint: keep at away from "0"!

It would be nice to shove it at least two bars to the RIGHT of "0", but with 550 primaries, you can lock them up under vacuum, at around 6kRPM.
This means, if you don't want the lock-up possibility, you need to drop them at least two bars to the LEFT of "0"; this becomes a pain in the ***, since you need to carefully tune the fuel in vacuum on the crossover!


-Ted

sbd

Ted, would you mind to elaborate why the staging bar should be away from "0"? I fail to see the logic behind this hint.

RETed

"cz"?
You part of hIGGI's crew?

It's standard "trick" I use to get away from the staging transition.
By moving the staging bar to an area where the engine doesn't see very often, it gets away from the hesitations that a not-finely-tuned fuel map can induce.

On the + boost side of the fuel map, you can get away with running it slightly run that needed, and the engine doesn't mind; that's just part of the rotary engine mystique.
So, if the staging bar is moved to the + side of the fuel map, even if you run the transition slightly rich, you probably don't feel it.

I usually set my Haltech tunes this way, but it depends on the driver.
I had one driver who likes to feather the throttle up to 7kRPM, which was just enough to run it under the staging bar (primaries only), and this caused them to lock-up.
It took me a while to figure this out, but I eventually saw that the pulsewidths was hitting 100%. :P
This is what happens when you run 550cc primaries with a big turbo upgrade.


-Ted

billzrx7

so you thinkin if i moved my staging bar to 14 instead of 12 (2 bars into +) it would help in my transitioj from the 850s to the 1680 kickin on? the 850s can handle a few lbs of boost no problem im sure. cuz anytime i hit boost (and i can do it almost anytime iwth this small hotside ) it cuts and dies unless im higher in the RPM range

sbd

No.

Going through all described symptoms, I am starting to suspect the throttle pump enrichment settings ( too much TP enrichment and sustain rate) have a significant impact on staging smoothness.

sbd

No.

Going through all described symptoms, I am starting to suspect the throttle pump enrichment settings ( too much TP enrichment and sustain rate) have a significant impact on staging smoothness.

burn4005

this may have already have been covered, or not relevant to your ecu, but are you tuning the Auxillary Staging map as well as the main fuel map?

the e11's i have tuned have an extra 2d fuel map right at the staging point for the primary+secondary operation, rather than just the primarys that is what is shown on the main map at the staging bar.

this allows you to tune the exact staging point for both primaries mode, and staged mode.. if you fiddle with this for a while, it may help.

but as i said, you may be already doing this, or your ECU dosen't have it.

good luck anyway!

im running 720cc primaries and 4 X 900cc secondaries (the ecu is driving 2 secondaries per channel, im finding this gives better atomisation at the lower staging values.

Silver7

Ive tried everything Ted mentioned, and so has Keith. Moving the staging bar to the right just moves the stumble to the right. Running the staging bar to the left (vaccum) is a nightmare since that's where most driving is done. I still think the problem is car dependent. I have friends that have no stumble at all with base maps loaded. I am lucky to get my car to a slight stumble (when coming off of boost) and I have spend a lot of time with the transition part of the map. I have even taken my car to a well known rotary shop and he didn't understand why my car stumbles the way it does and couldn't tune out the problem. I have tried everything within reason to fix the problem and have come up empty handed (and so has keith). If anyone comes up with a fix or any other ideas, please post them.

RETed

Hmmm...this is a long shot, but what is the total advance and ignition split at the staging bar areas?


-Ted

Silver7

I've tried so many configurations... to keep the car consistent I set the timing 10 degrees across the board so that the timing is not changing while the injectors are staging. I will have to look at my split. I generally stick with the split supplied with the base map. My base map was taken from Hitman's site.

Silver7

If it helps, here's my fuel and ign mod list:
bosch pump
stock filter
stock lines to engine
fuel rails in parallel
SX FPR
72 lb primaries - custom rail
160 lb secondaries - custom rail
stock ingition with Mallory CDI
Haltech E6K

Lowering fuel pressure seems to help, but if I go lower than 38 psi static pressure, the car begins to have trouble idling properly.

rxrotary2_7

Josh, I have looked at all my old maps trying to find what I used to run it without staging. I believe the laptop that had the maps on it was sold to Ricky in PA (lancaster maybe?) with the black 3rd gen. I cant recall his name on here.... I thought I saved all these maps somewhere, but I guess I didnt.

Silver7

Thanks. I will ask ricky about the maps. I installed his haltech and have access to his computer.

RETed

Okay, the engine is seeing 10 degrees total advance when it hits the staging bar - did I get that correct?
If this is so, first...I'm surprised the car runs okay set like that.
Two, jack up the advance at the staging bar area...the higher the advance, the less and the less the hesitation should be felt.
I'd get it at least around 30 degrees total advance right around zero...minimum.



-Ted

Silver7

I am having a hard time understanding what timing has to do with the injectors staging. I have a wide band as well as an autometer A/F gauge that I use to tune vacuum fuel maps. The car stages very smoothly but I can see a slight lean blip in the autometer gauge. When the engine comes back to vacuum and "unstages", I feel the engine stumble and can see another lean blip in the autometer A/F gauge. I have tried many different timing configurations including different split settings. I usually start the timing at 36 degrees and work it down to zero by the time it reaches the last bar (30 psi). I set the timing to 10 across the board just to take the ignition out of the equation. I didn't want it changing while I was staging my injectors. I just tried this while troubleshooting, I don't normally run it this way. Needless to say it did not make a difference, which leads me to believe it's not a timing issue.

Here's the history:
The car ran perfectly with stock ECU. I installed haltech E6K and 160 lb secondaries at the same time. I used the stock rail and FPR, I just modified the rail for the new injectors. Everything else was stock except for the fuel pump. This is when I developed my stumble. I slowly replaced everything one by one hoping to find the problem. I even swapped ECU's with a friend to eliminate the ECU as the problem. I swapped secondary injectors with a friend. I changed rails and FPR. I swapped primairies to 72 lb top feed. I ran the rails in parallel. I added grounds to the engine. I inspected all wiring to the ECU. The only thing that really did anything at all was lowering the fuel pressure and spending a lot of time fine tuning the bars around the staging point. I haven 't experimented with injector phase maps or throttle pump configurations since I am not to familiar with them. Can anyone explain the injector phase maps?

RETed

Waitaminute...
Is this an E11?
V1 or V2?

If this is an E11V1, I *know* you can't get rid of that stumble.
If it's an E11V2, I'm pretty sure they haven't fixed the problem either...?


-Ted

sbd

He says E6k in his next post.
However I have completely different experience with the E11v2. I have unnoticeable staging at atmospheric pressure using primaries hold mode. Within the tuning process I had a bit of a stumbling which appeared to be mainly due to the throttle pump settings. When you think about it the enrichment is defined as percentage of the injectors pulswidth. When you get at the staging bar and the throttle pump enrichment is active, you have both injectors firing the respective percentage longer. Having in mind that at the staging bar the fuel supply capacity is quadrupled (550/1600) logically at the staging point you have substantially more fuel flowing into the combustion chamber. So even if the main map is tuned perfectly if at the staging point the throttle pump enrichment map is active, there will be very rich mixtures and therefore stumbling.
After a little playing with the throttle pump maps and deceleration fuel cut settings, I have flawless staging up or downwards at virtualy atmospheric pressure.

Silver7

This is promising. I will have to mess with my throttle pump settings.

Ted - I have an E6K. There is a map for injector phase but I don't mess with it cause I don't know what it does.

RETed

Ah, ok, that explains a lot.
I never got to thoroughly mess with that option, since we were trying to get the default staging mode to work.


Did you mess with all 4 throttle maps or just the two "main" ones?


-Ted

RETed

Ah, sorry, I was getting all confused, and for some reason I thought you mentioned two alternate maps for injector staging (which the E11 does have - maybe Halwin for E6X too?).

The throttle pump theory does sound like a good idea.
Keep us updated on this!


-Ted