I can't get rid of the hesitation I have at 2900-3200rpm with the Link 2. It feels like a revlimiter almost until u pass over it. I have the datalog and map if anyone wants to look. The only thing that shows up on the data log when this happens is the voltage drops from 14.0 volts to 13.9 volts. This happens at anything heavier than very light throttle. I can't attach the map or datalog, but if you give me ur e-mail I can send it.

Relevant Mods are:
Link 2 (wired myself)
Ludespeed stage II
SPG mod

-Chav

P.S. Skywalker, you have a pm. :)

check your spark plugs...I'll bet you have to get new ones.

Right now I have a slight hesitation at around 4200RPM. I even had it when my car was N/A with the Link. I know your supposed to run a bit richer and take some timing away from there but that hasnt helped at all.

I just put in the 7 heat range copper NGK's like three weeks ago. I'll try putting in a new set tomorrow, see if that fixes it. They're so cheap it wont hurt to try. Thanks for the suggestion, I'll report back on the situation tomorrow.

-Chav

7 heat ranges? Thats a huge difference. Wouldn't 2 be more appropriate?

Actually you should try NGK 6's. They are one step colder which is what you should be using.

I put in the new plugs and checked the old ones. You can easily see that number 3 is running lean when compared to the rest of the plugs. 1,2,4 are identical while 3 has a brownish spot on the electrode while the rest have a black/brown spot. While I was in there I also checked the compression all are within 5psi of 200psi. I also checked the wires which are fine. I then reloaded the link 2 and than loaded the map I've been using while the car was running. The car has the exact same hesitation.

6 heat range NGK's are stock and 7 heat range are one step colder. NGK is weird in that higher numbers indicate a colder plug.

Skywalker, I'm hoping that you have an idea about what's going on because I'm completely stumped. :confused: It hesitates the same with no timing throughout the map as well.

-Chav :(

7's are fine. I honestly have no suggestion as a solution to the problem. *shrug*

Oh yeah that's right my bad 7's are the colder step. I always mess that up.

Your timing looks a little low between 2900-3500 RPM's. Your fuel looks a little high in that area also. Try adjusting those items and let me know how it turns out.

Also PM'ed you some more info.

Fixed!! :D Skywalker is da MAN!

The entire map was really rich, I went threw and redid the map and it looks much better. What I didn't expect is that between 20% and 80% throttle the same amount of air is flowing threw because of the boost. I was tunning the car like it was still n/a and adding fuel based on throttle. I had to lean out the area with hesitation by 60. :eek:

-Chav

Is the Link TPS based load maps??? :eek:

sweet!

I'm having very minor misfires in vaccuum. It seems to occur between 3000-3500rpm. I was running NGK BKR7E's then fried those when I put in the new injectors, ran too rich initially :)
Then I put in Denso Iridiums and those seemed to work well but I had a few misfires in vaccum occuring randomly.

I just put in the last new plugs I had which are the BKR6E's and now the misfires are VERY small. The car definitely seems to like running on copper's (thank God---cheaper :) )

The problem I cant seem to fix is that when in WOT, I get this jerky hesitation at right around 4000-4200RPM. I know I'm supposed to pull back a little timing there and maybe richen it up a little but is there anything else I should do?

I have row settings to MAP. When I put MAP+TPS, the car does not start again when I turn it off. Since I have MAP settings, I also put enrichment to MAP as well.

Any help is appreciated.

8complex, I have it set on map + tps. There are other options such as only map or only tps. Under the map + tps mode it will go by the tps reading to determine fueling and enrichment (when under vacuum), but when there is boost it will go soley by the map reading. In my map it would run fine under vaccuum and then 2900-3500 (when the turbo built boost) it would switch to the appropriate zone and dumb fuel in.

WRC 555, I'm on my way out now, but my car doesnt have the 4000-4200rpm hesitation. When I get back tonite I will tell you what I did to solve it.

-Chav

WRC 555,

You actually trying to fix a common problem most people have, including myself. You said you are getting hesitation right around 4000-4200.

This is a problem point in the RS especially, even with the damn stock ECU I had this problem except much worse. When you are driving hard, and shift quickley between gears this is where the next gear up usually starts, so you will run lean and possibly ping.

The solution right now is to set the values to where you think they should be for driving normal driving and then lower the timing point about 2 degrees around this area of problem (4000-4500 RPM's, and MAP based on boost levels). Try to keep the fuel consistent around that area if not lowering it a tad.

Yeah I'll keep the fueling the same. I'm running pretty rich right cause when I take out the plugs they are pretty black. Its a 10.5:1 ratio in boost so its not too rich but safe.

I dont really trust our stock knock sensors but after datalogging my knock it really good. It climbs from 5 to around 20 consistently to redline with no big jumps.

The funny thing is at the point of 4000-4500 there in no pinging, its a steady 8-9. So it maybe the cams or something?

I'll try taking out around 2-3 more degrees there and see what happens.

There was a time when it went away, but after the turbo went it came back :(

We have to figure this out so I can focus on tuning for 10psi :)

btw skywalker...what spark plugs are you running?

Thanks for your help!

Hmmm, I wouldn't take out anymore timing in your case. It sounds like you are just running to rich, I would try lowering your Master Fuel a little bit, but try keeping your idel around the the same point if it is not to rich. You should be at 11.0:1 - 11.5:1, for optimal use.

If I lower the master fuel then I would have to re-tune all over again cause all those numbers in every zone would need to be raised appropriately right?

Let me try leaning it by a few points in that area and see what happens.

That's funny. My hesitation went away after I put on my turbo. Just some lucky tuning I guess :rolleyes:

Skywalker hit the nail on the head. That is exactly what I did to get rid of the hesitation. It is a combination of pulling a degree or two out of the timing, and leaning the mixture. This worked for me with the turbo, but didnt do much when I was n/a. When I was first n/a with the Link the hesitation was very bad and when I did what Skywalker said the hesitation became more like stock. Jeremy (HndaTch627) said
here (http://forums.i-club.com/forums/showthread.php?s=&threadid=235100&highlight=air+valves+jeremy) that it has to do with the air valves at the tip of the injectors. This and the cam theory are the only two I've heard of that I believe are the possible cause.

-Chav

I'm still stumped about the hesitation. Reducing the fuel worked for the part throttle hesitation, but made the car run lean at WOT. Rerouting the vacuum lines helped reduce the hesitation, but now it is back. I can't figure out what is going on. I do have a few theories though.

Bad Link 2 ecu

Something with the dual feed fuel lines

The stock FPR is too much of a restriction and the fuel pressure goes up so high that the injectors go static and stick closed/open.

Something wrong with my injectors

While driving the other day I noticed that if I'm crusing and driving in the 3000-3500rpm range and give it throttle than let off several times over the hesitation point the car will start to ping. The whole car shudders as I pass over this point. What to do?

I'm thinking about buying a fuel pressure gauge and seeing if my theory of the incredibly high fuel pressure at 3000-3500rpm is correct or just buying an svx fpr. Lately I've been leaning towards a glitch in the Link 2 especially since the data logs show nothing out of the ordinary during the hesitation (except you can see where the rpms don't increase steadily). I'm also doubtful of the dual feed fuel lines or fpr causing the problem because many other people have a similar set-up. Maybe the injectors are to blame, but then the idle would suffer.

The weirdest thing is that when I first put the turbo/link2 on the car it would hesitate at 4500-4600rpm 5100-5300rpm. The hesitation was so rough that it felt like someone ran into the back of the car. Than after playing with the link 2 the hesitation at those points went away and moved to 3300-3500rpm.

-Chav

Yo Chav,
If you can post up your PCL and a datalog somewhere, Id be happy to look at it and see if I can see anything.

Try setting fuel injection mode from "sequential", to "group" firing.

I had the same problem, and it got rid of it.

Don't you have to rewire your injectors to only run off of 2 chanels if you do that?

Says in the link manual that you should run off channels 7 and 8 to do that. Besides, you car is *supposed* to run sequential.

Yes the manual says you are supposed to run just wires 7 and 8 for group fire. However, I was beating my head against the wall with CHav's same problem. I tried group fire mode, and problem was solved.

Remember, the Link fires in group fire method when cranking. The largest benefits to sequential are early in the rev range, and also for emissions.

There are plenty of 500+ HP hot rods that use carburetors instead of sequential fuel distribution, so running in group fire doesn't make me feel so bad.

xephyr, THANK YOU! That fixed it, but I'm :confused: as to why it did.

The hesitation was horrible and in order to see if it was the fpr I removed the vacuum line. The hesitation was much less evident, but not totally gone. Now with the fpr referance line removed and the inj. firing on group the car doesnt hesitate. Another thing I noticed is that while cruising it takes much less throttle and fuel according to my injector duty cycle gauge to cruise with it on group inj. firring.

The only reason I can see for this to work is if I wired an inj. wrong and it was firing one injector one cycle before the valve opened. I did check/recheck, and check again when I was installing the Link 2 to make sure it was right.

-Chav

I've double and triple checked wiring sequences with no avail; it's not the wiring.

Through several correspondences with other knowledgable individuals (in both Link and other ECU's), we have concluded the problem is one or both of the following scenarios:

1. The Link automatically converts to a "group fire" mode at a given combined engine speed and duty cycle. It would do this because basically injector pulses are occuring so quickly/frequently that it doesn't really matter anymore, and/or the processing capabilities are not powerful enough. Remember, sequential mode considers fuel pulse length, crank angle, and engine speed in order to fire the injector at the "correct" time. This is a lot to compute in a short amount of time.

2. Scenario 2 is the possibity that the processor is "bogged down" by the massive computations required, and thus causing hesitation as it "catches up".

As stated before in a previous post, there is no significant power loss to group firing (if any at all). Sequential firing was mostly invented for emissions reasons. If any compromise is made, it will be in the very low rev ranges. At high RPM, things are happening so quickly, it doesn't really matter. Also, group firing for the Link means half the pulse is injected per engine revolution, so it's actually a "semi-sequential" mode. Plenty of race cars did more with a carburetor, which is by far the most basic "group fire" method.

Mark Ramirez

Interesting thoughts xephyr. These senarios also crossed my mind.

I considered scenario 2, but I would expect the problem to be widely spread.

Scenario 1 was also something I was considering, but, again, the problem would be widely spread.

I'm happy that the problem is gone, but I'm also curious as to why the problem occured in the first place. Since there isnt any real power loss from running group I'm not too concerned.

Am I correct in my understanding of the ECU in that it uses the crank angle sensor to fire the coil packs and then cam angle sensor to fire the injectors? Could this be related to the cam angle sensor?

-Chav

So do you have to change your maps at all after switching over too group, or does the tuning still pretty much stick?

I had to change a few things. In seq. mode the car would ping on tip in throttle while cruising (row2). With it in group I can now advance the timing back up with out the car pinging and I also leaned out the WOT (row4?) row. I still get pinging at 5000-5500rpm but not nearly as bad as before (it would ping at 19-20 degrees of advance including the base 10 before amd now I have it set at 24 degrees of advance including the base 10 with no pinging).

-Chav

Cool, I'll have to play w/ that.

Chav- Yes you are correct about the sensors. To elaborate on the topic, the cam sensor is used to identify which cylinder has its intake valves open, therfore its use for sequential fuel timing. It is also used to determine which bank to ignite (bank 1/2, or bank 3/4). In group mode, the crank sensor is essentially the only sensor being used for fuel. The six teeth on the crank sensor give enough info to determine rpm, and TDC.

Hey Chav,

Are you using the same vacuum setup for all your accessories such as bov,wastegate, (linkplus on the throttle body)and etc.. as the ones I pmed you?

If you have the plug and play do you have to change the wiring or can you leave it alone and still change to group firing?

Thanks!

Sorry Imprezha I haven't checked my pm's in a lil while. The top vaccum port goes to fpr, bov, and link 2 and the bottom port goes to waste gate, boost gauge, and cruise control. It works soooo much better this way then with everthing on the top port and only the link 2 on the bottom port. The wastegate open's smoothly and I can control the boost with the throttle (before it would just go to max boost at 20% throttle). Also the throttle response is much improved.

I haven't changed the wiring from group firing. I'm assuming that in group firing it fires all 8 injectors once per engine cycle and it doesnt really matter which injector is hooked to which line.

-Chav

P.S. I just read your pm's. If you like I can send you the pcl file I was using with sequential firing. The group firing map I'm using is a little different in that the timing for row 2 and WOT is up by 6 degrees. Let me know ur e-mail if you want me to send it.

Thanks alot Chav!

with the new vacuum setup, is the zones moving to row 2 and 3,alot more often or is it still basically using row 1 until you hit boost? I have changed the settings under row step to MAP and
under enrichment to MAP and It seems to utilize the other zones
under vacuum. I'm getting better gas milage too!

I'm going to try your settings and see how that works out!
Thanks alot for your info.

I got your email. Thanks for sending it so fast!

Later, :)

Imprezha

No problem. :) I have noticed that under map + tps it takes a lot of throttle to move into another row. It interpolates between the rows based on the TPS under vacuum so I'm not worried about the a/f ratio being off. The throttle response is better with map + tps so I've just left it like that. I still havent gotten out to the car with a disk, when I do I'll send you the map I'm using for group.
:cool:

-Chav

Originally posted by Chav
[B]I still get pinging at 5000-5500rpm but not nearly as bad as before (it would ping at 19-20 degrees of advance including the base 10 before amd now I have it set at 24 degrees of advance including the base 10 with no pinging).


Ever have any luck? i have the exact same problems. they don't seem to change with boost, fuel or ingnition map changes.

bump

bill harvey

Pm'd ya.

-Chav