ok, im stuck, cant figure this out...need help

[Sin'sVr4]

So, ive had the 23psi wall for awhile. Car runs absolutely amazing at 22.5psi. screams, no issues pulls hard as fuck. If i turn the boost up to 23 sputters and seems to flood itself and i have to rev it a bit to clear it out.

I am running an HKS DLI and msd 8.5 wires, new bcep7 plugs, and new coil packs and ptu. swapped them out with new coil packs, ptu and plugs and still running like shit over 23psi. fuel pressure is set to 58psi.

I logged and afrs are 11.5-11.8 (E85) wot and everything looks great on the logs. Im not sure what else i can do? plugs are gapped to .024. i had them at ,028 and ran exactly the same. I have no idea where else to go from here. Anyone have some ideas for me to try and t/s? Im just frustrated that i dynoed the car a couple years ago at 26 psi and now i cant get near that?? last year car wouldnt boost over 20.5, got her up to 22.5 but thats it.

Timing maybe? im not sure. The tune i have on it is what I ran 11.80 @. So...not sure what is up. Need some help from the tech guys. Is there some part of the ignition im overlooking?

Mike

[aaronatstate]

81 psi is a lot of pressure. What fuel pump(s) are you running?

[anyonebutme]

what injectors? some brands don't like being fed 80+ psi.

[CoreyB]

Are you seeing any knock?

[Sin'sVr4]

I'm running a wally 400 e85 pump, pte 780 inj with aeromotive 1000 fpr. At 23 psi i see some raw knock. .035 is the most I see

[Sin'sVr4]

If someone could look at my logs I would appreciate it

[NOMIEZVR4]

E85 likes closer to 12.1 from what I'v heard

[futurevr4man]

58psi base is awfully high. Try turning it down a few psi... Stock is 43 for reference. 58 is quite high.

[TurboSinceBirth]

Do you know what your IDC is? Also, is your fuel pressure rising 1:1 and what happens at WOT 23 psi? Does it drop at all? I agree 58 base is high. The pressure relief valve in the Walbro may be opening up. I want to say around 70-75 psi is when they open up on the 255 Walbros. Not sure if the E85 400s are different. You'd have to look it up. That could be a possibility. Your DLI may not be working and I don't know how to test that out. I would almost think there's a fuel issue which is why I'm curious about your IDCs and fuel pressure. With 720s I could only get to 19 psi on E85 before running out of fuel so I'm almost wondering if your 780s are nearly tapped out although if you used those same injectors at 26 psi before there could be something else wrong. You may try leaning it out to 12:1.

[Sin'sVr4]

I will adjust my pressure when I get some time. what should I drop it to? 45psi? I remember the tuner raising the fuel pressure to help compensate for me only running one wally 255 back in the day.

[donniekak]

Try leaning it out, and gapping the plugs down to .018". It also may be an issue with the injectors opening with that much pressure. What are the afrs when this happens? What do the plugs look like?

[Chris@Rvengeperformance]

you sure your tune isn't setup to cut ignition at a certain load? I thought you were only running 780cc injectors anyway?

[Sin'sVr4]

yes im running 780 PTE's. I dropped the fuel pressure to 47psi. im not sure what dropping the fuel pressure will do. Any thoughts? i know when i was running a single wally 255 that was to compensate for the small pump. Will this affect anything? Ignition cut is only on my 2step and NLTS that ive noticed. Where in my aem can i see if my ignition is cutting at 23psi? that is what it feels like

[Chris@Rvengeperformance]

99% chance the high fuel pressure is to make your injectors flow more. I have no idea where to check that, I don't tune aem. I'd get it to your tuner before you hurt the motor experimenting.

[HLxDrummer]

You probably already know this but with the lowered fuel pressure you will probably run lean on the same tune (I don't use AEM either so I'm guessing). Just be careful!

How does the tune compare (both fuel and timing) at 22 PSI and at 23 PSI?

I doubt it is a fuel issue because the AFR is fine (unless it is a spray pattern/atomization issue or something). High fuel pressure would affect the injectors at 22 PSI the same as 23 PSI I would imagine. Maybe try bringing fuel pressure down 1-2 PSI and see if you now have an issue at 24 PSI of boost.

I would look through the manual and see if there are any safety parameters that need adjusted. Perhaps when you hit a certain load/PSI it cuts something as someone mentioned. I just can't imagine such a drastic change in performance from 1 PSI being a mechanical issue, you know?

Do you see any black smoke out the exhaust when you try 23 PSI?

[donniekak]

you sure your tune isn't setup to cut ignition at a certain load? I thought you were only running 780cc injectors anyway?

Ah, yes. Forgot he was tuning with aem. The boost cut could be the culprit.

[mb3000]

I would review the afr's in a small idle "low load" square and then see what difference in the tune the lower fuel pressure makes. From there I would compensate the rest of the map with additional fuel, keep the fuel pressure at a decent level and upgrade injectors.

[Sin'sVr4]

ok, ill try the fuel pressure at 55psi, then check the logs.

[familyMAN]

If you drop pressure you are changing your tune. Before you drop your base FP, take a log and post it for download so anyone that has aemlog can review it. What is your fuel cut load psi set at?

[Sin'sVr4]

i put it back to 58psi for now. I will check that out when i get some time. raining and working = no time to tinker

[Sin'sVr4]

my fuel cut load is set to 19.88 psi

[familyMAN]

Well there you go. Raise it to 25psi.

What were you basing your 22.5 and 23psi readings on, gauge or log?

[Sin'sVr4]

I was basing it on my greddy profec b and guage. they were close. Logs were reading a lot lower...17.5? I would hit peak boost and that's what I was basing it off

[familyMAN]

Makes sense then. Raise your fuel cut and give it a go.

[familyMAN]

Update?

[Sin'sVr4]

i need to get new plugs. install them and then retest. ive been so busy with work havent had a chance. probably order the 7bcep's ngk's or what ever that part number is lol. Chris told me the 8's were to cold for my car and will foul out real easy just driving around

[2faststealth4u]

Sorry to hear SIn still running the purple beast?

[Checkered vr4]

i need to get new plugs. install them and then retest. ive been so busy with work havent had a chance. probably order the 7bcep's ngk's or what ever that part number is lol. Chris told me the 8's were to cold for my car and will foul out real easy just driving around

It depends on how often you get them "hot," I run an ngk heat range 9 non-projected tip plug all the time and only had an issue once and it was a road trip (4+ hours highway driving). I also drive aggressively though.

[mb3000]

I used to daily drive non-resistor 9's with a TD04 pump gas car. :dontknow2:

[AdamVR4]

99% chance the high fuel pressure is to make your injectors flow more. I have no idea where to check that, I don't tune aem. I'd get it to your tuner before you hurt the motor experimenting.

Lowered the fp on e85 then spun a bearing. Coincidence? ...

http://www.3sgto.org/3000gt-stealth-gto-related-topics/12743-fixed-my-boost-issue-but-spun-bearing-morning.html#post250869

Now hes likely parting out a car with 75k on it. Sigh...

[familyMAN]

IMO 75k doesn't really matter when nothing on the car is original including the bumpers and paint. Part out would net the most $ but depends if you have the time and patience.

Depends what he wants to do with the car but since he is running e85, he could easily drop in a 10:1 non-turbo shortblock on the cheap and still run 4-450hp easily on the cast crank or more on a forged. Enjoy or sell as a running car.

[Sin'sVr4]

didnt, lower the FP. kept it the same. Didnt want to change anything until i went thru the new plugs and test all my ignition components. Gonna pull the plugs, and pull the rear turbo and make sure all that is ok