you may have something there...sometimes to get down to 2600 RPMs I am downshifting from 5th to 4th on the interstate [hard braking and decel] until I get to those RPMS them immediately WOT. Sometimes I fall in below that range and have to accel a bit before hitting the gas.

could be that some of the guys I am tuning are doing something similar when their logs show lean for no reason.

@Boost_creep do you do this? your latest logs have been great but a few revs ago they were way lean on the first run and I haven't made any maf changes to that degree. I'll look back at those logs to see.

@rfinkle2
I will get those logs to you asap, those peskie state troopers have been hanging out in my data log test strip. The freaking nerve of them!

I definitely think @rfinkle2 may be onto something there. Yes, I do sometimes ease up on throttle, enough we're the injectors are turning off. I did not even think that could be related to the issue. There is a very good chance that this is why some of the logs are a little wonky.

I'm going to get some more logs for you tonight @Dano
I'll make sure to not do this, and well see the results. Lol.

I think I'm addicted! I think I will be going to 100% very sooonly. Like next fill up this damn stuff is sweet.

@rfinkle2,@phate,@silvapain

Based off of recent data posted by our 100 percent E users I would not personally go 100 percent unless you have a back up spill valve for "just in case" or an alternate vehicle should you need to get a spill valve if yours goes out. Just my opinion.

I hearz ya,I'll pull the sucker out and clean it if needed. Drop it in an ultrasonic cleaner with gasoline might do the trick.

It's definitely addicting :).


Tapadatass

hahaha, I've gotten a few messages just this week from the E85 or eth mix guys and all have said the same: their car feels slow as hell on straight gas!

I don't have to tell you this week, I tell you all the time! Oh and winter tires and 30 degree weather ain't helping. At least I look forward to 25+ mpg.

Every time I fill up I miss the gas mileage, but only up to the point that I pull out of the parking lot and punch it:slomo:

All,

I'm looking for some volunteers to help me test some new tables we've opened up. On my car, these tables are allowing me to run 75% E85 to 25% 93 while still running my MAF scaling from 93 fuel. It allows me to run any mixture and can compensate for the changes.

Ideal candidates are proficient with ATR, have a solid MAF scale from when they were on pump gas, and are currently using some sort of E85 mixture.

Basically, I'll need people to send me a copy of a map that they used with pump gas (to get the pump gas MAF scaling) and tell me how much E85 they have in the tank and I'll send them a map back with a few updated tables (that will still be hidden for the time being) to test on their car and for them to datalog. We'll be looking for your trims to stay within reason and for your car to still be able to hit targets in OL.

Send me a PM if you're interested! The people whom I've already contacted, well, feel special. :wink1:

Cheers,

Evan@COBB

Great to see you giving e85 some research @Evan@COBB!

That infamous E torque is hard to ignore. :)

High Five Evan! :sasmokin:

Responded; will be driving again within a week, give or take a couple of days.

PM sent.

So I have another awesome and interesting issue with fueling...

Now I have only ~60 psi up until 3000 PRM, then I get full pressure. It's interesting because it's like a switch at 3000 RPM; right below it and it's at ITFP pressure, as soon as I hit 3000 RPM I get full HPFP pressure. It's consistent and repeatable.

Any thoughts?

HPFP desired pressure tables....lol

i have had weird things happen when moving a map forward through a FW or ATR revision.

I wish it was a simple table change. I haven't made any map revisions recently, and I was having no FP issues before last night (when this started happening).

I remember there being some sort of low speed resistor for the ITFP... Maybe I need to bypass it?

So you fubared my spill valve in what...3 days...or did it ever work?

the resistor is on the driver side frame rail in front of the battery box but not sure that would be the issue.

Yeah, mine too :) Identical issue, except my switch is like 3200rpm haha.

Anyway, I'd be curious to look at the voltage and amperage at the solenoid over the rpm range. Not much else can change, haha. Maybe I'll do some dj style ghetto wiring and hook up my mutimeter and have wires running everywhere, hehe. Yeah, this sounds like a good idea.

ps - I'm back on 93 for a tank. Not sure what possessed me to do this, but I did it. It's an opportune time to get a decent 93 tune, anyway. Dial in the maf curve and actually help out Evan's cause when I switch back to E in a few days.

b...b...but he just installed my SV which was working perfectly on my car...literally took the CDFP off my car, pulled the valve and sent it out. I have two CDFPs you know ;)

I can't believe he was able to phuck it up THAT quickly lol

has to be something else.

Silva, just out of curiosity, could you try reflashing your current map? Also check the AP readout for HPFP desired pressure.

The spill valves are fine. With gas, they work perfectly. As soon as they get some high eth content, they have issues sometimes. We think it could be a lubrication issue with the plunger and collar or the plunger and that little c-clip in the solenoid....

hum....well get my SV outtta there Silva!!!

BTW I ran about 6 tanks of E35 through that valve and 6 tanks of E27 before that but I suppose any petrol will lube the valve up.

Silva could put a few gallons of that old time dyno fuel in there to see if there is any improvement.

yes hot wires, fuel...solid plan.

thinking a bit more....he and you have put thousands of miles on your SVs before you saw any seemingly permanent issues such as this. Then he installs my SV and IIRC he said his pressure was fine but then a day or two later this issue arises.

I just don't see that valve getting worn out in that short of time.

maybe he'll chime in to confirm the new valve did in fact work for a period of time.

LOL. No, I got a junkyard pump in and that's the spill valve currently in my car (and possibly fucked). I'll be sending yours back to you tomorrow hopefully.

I might try bypassing the resistor as a test to see if that fixes the issue.

The spill valve worked perfectly for several days and then this happens suddenly.

I checked my HPFP tables and everything looks good

I know who might have some insight on this, but dare I mention his name?

I tried to contact him already about my chirping, but noone answers their pm's on Cobb's forum.

The fact that it changes at 3000 RPM every single time, and if I keep RPMs above 3000 I don't have any pressure issues, tells me that something is changing from the control system at this point. Whether it's the ITFP speed changing, or the voltage/amperage on the spill valve, or something else I don't know.

what about adding marvel mystery oil to help keeps things lubed ?

IIRC Silva already runs MMO

Yep. I follow the bottle and use 4oz for every 10 gallons.

ok...back to the SV...I don't see one failing that quickly considering you guys have run them for thousands of miles without this issue...and after a few days one is gonna fail, and begin to work at the exact RPMs each time...isn't this a new failure mode?.

sounds like software to me.

just resave your map and reflash no matter what the tables appear like. it takes 5 minutes.

maybe even change some values in the HPFP tables just to get a different byte size on the map.

I know for a fact it is not tune related. I am back on 93 octane for a tank (idk why). But, while I'm on 93, I'm doing some testing.

Before I filled up with 93, my car was VERY hard to start because the spill valve solenoid (SVS?) doesn't like to work when it's cold. It would take a few tries. Once started, it wouldn't work unless above ~3k rpm. While cold and below 3k rpm, it would not work. Once warmed up, it would work fine unless I tried getting into boost below 3k rpm, then it would stop working.

On 93, i have NONE of these issues. The car fired on the first crank this morning, had good HPFP pressure, and never once had an issue.

ok boss...very strange.

so do you think the valve doesn't get ruined it just doesn't have enough lube to free itself?

Reflashing the exact same map can rule out a potential bug in logic, though. Perhaps there is something going on we can't see.

I only suggested this as there were a couple of times I was having problems and broke the pump down, cleaned it, and flashed a modified map (back when you were helping with my leaky CAL) only to find that my pump was clean; yet for some reason it still helped for a few hundred miles.

That's EXACTLY the same issue I'm having right now.

I have a new beta map from COBB now too, so I will try a reflashed map of mine and their map before trying anything else, just to rule out software as a cause.

How about adding some more 93 until you don't see this issue and then go back to the higher concentration of e85 untill you can duplicate the fp problem. Just a thought.

I've recompiled my E85 tune(s) in fresh maps a couple different times, so I think it is highly unlikely. I'm going to break out the multimeter tonight to see if I can spot anything interesting with the spill valve as rpm's rise.

Could this be temperature related? Does it change once the car warms up or if it idles for a while?

To test "lubrication" and if the issue is reproduced all the time, coat the spill valve parts in assembly lube. Of course this is given if taking it apart in itself doesn't temporarily also fix the problem.

A scope will give you a good idea about what the control system is doing.

Unfortunately no E85 in Western Canada so I can't play with the good stuff :(

The issue started for me after the car sat outside for 24 hours while I was out of town for work. However, it was also an issue this morning after sitting overnight in my heated garage.

I don't have enough data on this issue in my car to be able to tell if it's temperature related.

Some of this seems to be temperature related. The cold starts being a bitch is definitely temp related.

But at the same time, I've had the car stop building fuel pressure when under 3k rpm after driving it for hours, so no temp dependency in that case. I think there is a temperature variable associated with how much gunk is in the spill valve.