what would cause the ecu to pull a ton of timing so low(tip in to 1800rpm) and then go back to normal...

had my tuner "fix" the problem with a real time map and it got worse, almost to the point of sputtering out at tip in from a dead stop.

anyone have any good ideas on this?

Show us some logs please...

i dont have a log, my tuner looked at it last night, ill see what i can get for yall

Don't get offended, but maybe it's time to find another tuner... How exactly did he "fix" your problem if it's worse now?

by fix, i meant that he adjusted the realtime map with slightly higher values, ie adjusted timing so car would react a little better at tip-in. i trust my tuner to no end as he has tuned a ton of members cars. something is making the car pull gobs of timing in the low rpms.


the question is, what would cause the ecu to pull a ton of timing down at the low end, from idle to 1800 rpm.

this is not questioning my tuner at all. just looking for ideas as to why this would happen.

i would like to be able to go back to my tuner with some possibles and mabe a solution.

thanks again folks

If it's deting it will pull timing, but I can't tell you that's what's happening because you have no logs to show anything. Your other statement that you should be going back to your tuner to "help" him fix your problems leads me to believe that if he was competant then he'd be aware of what could be causing the issues. One thing you need to be aware of is that if your tune was done on a dyno then you MUST also do a road tune to see how the car behaves to the tune based on the driver's habits. Dyno tuning is fine for top end power, but no so good for everyday drivability.

Is your tuner just shruging at to why it's pulling timing? You need to get some logs or something... was he the one that told you that it's pulling timing?... or are you just guessing?

at such low rpm, I wouldn't be surprised if the resulting heavy vibration is rattling something and fooling the knock sensor into thinking there's a ton of knock.

my tuner is Riftswrx, so he is not new to the game of teh tune.

as far as why it is pulling timing, he said drive a day or so and we will look into it more.

could something loose really "trick" or "fool" the car into thinking its knock?

as far as the tune, it was done on the road. i will get some logs asap and let you all have a look at them.

thanks for the answers keep em coming

Is your tuner just shruging at to why it's pulling timing? You need to get some logs or something... was he the one that told you that it's pulling timing?... or are you just guessing?[/QUOTE]


i saw the map with my own eyes with my tuner looking at it.

standard pull for crappy winter gas here and there, only two fields i saw. everything else looked great.

but low end idle to 1800 is where it pulled a ton of timing.

Riftswrx knows what he's doing. Have him post a data log here. What are your mods?

vf39
sti pinks
walbro
txs hyperflo top mount
buschur tbe
gfb pullies

Yeah, Riftswrx should know based on all the tune outcomes I've seen from him... However, he tends to tune a little differently then everyone else... he likes lean and retarded tunes. If he changed that section of the map as well (from stock layout) maybe your engine just doesn't like the new setup. Most tuners change map characteristics within a range that affects overall performance, but tend to leave the low rpm and idle sections untouched. I guess we'll have to wait on the logs.

On a side note... you don't have different spark plugs then stock do you? I recently tried changing mine to Iridiums and my car (with my perticular tune) didn't like it and wanted to pull timing. Ended up having to go back to the OEM Platinums.

what are the actual advance numbers here, after being pulled by the ecu?

I'm thinking it's a few possible things. Since it ONLY happens, RIGHT on tip in.

A: a fuel delivery issue
B: a spark issue
C: a noise issue

This was the method in my testing.

At one point in time literally between .24 and .4 calc'd load, and 500 and 1800 RPM (something that will mean something to any street tuner owner), the system pulled out 15!!!! degrees of timing.

So.. for grins, I actually pulled out those 15 degrees just to see what would happen, and reset the ECU.

It was fine for a little bit, and got worse, which tells me it CONTINUED to pull out timing.

15 degrees is the defined limit of the maximum amount of pulled timing. So I knew the system had bottomed out at that point.

Seeing that Mike quickly still had issues, tells me that it's most likely going to be one of the options I listed above.

The rest of the knock correction map had the anticipated +.5 degrees here or -.5 degrees there (tuned on summer gas, and now on winter gas in the midwest). So that's all perfectly in line, with an IAM of 16.

But IMO, I really think it's noise induced. It would NOT be the first time I've seen that happen.

Jorge (RiftsWRX)
www.ProjectWRX.com

ill throw out the noob suggestion .. how about a new set of spark plugs

ill throw out the noob suggestion .. how about a new set of spark plugs

Don't think he's done that, but that will be the typical things to check out next

Plugs, coils, fuel filter, loose shields, knock sensor torque spec, etc.

Jorge (RiftsWRX)
www.ProjectWRX.com

these are what i pulled today, let me know if we need more info i can run a few more.


http://www.defamationmedia.com/ovrclkdpmp/

couple things i would check-

the tbe mounts
the tmic mounts

maybe its just a weird vibration at those rpms that is causing it to throw off the knock sensor. maybe even check the covers on the header.

another possibility- b0rked accessecu. maybe revert back to stock, use the tari logging and see if it pulls timing there even on the stock maps.

Yeah Mike.... what we've all said... your logs simply confirm that it's ONLY happening off idle.

Start looking at the mechanical suggestions we've all listed.

Jorge (RiftsWRX)
www.ProjectWRX.com

10-4 captin:D