Running way too rich w/ Motron 80lb Injectors

[hardrock21]

I'm not seeing a lot of tuning info on these injectors, but they are what I have. A lot of people have had their hand in tuning on my car and I know just about enough to be dangerous.

That being said, this is the deal, the idle is fine, around .98-1.04 lambda, but anytime I am on the throttle at all cruising, it buries itself at about .68 and stays there, spits/sputters/etc. STFT's are requesting to pull 30% fuel at a time which doesn't make a hill of beans worth of a difference in the runability, I was pulling fuel like crazy and just kept reading .68 so it has me wondering if something is wrong in my injector calibrations or any other table that may affect it. In my mind, the injectors should be able to slow down enough to lean it out since it is alright at idle, right? I'll post the tune and ask for advice, like I said I don't pretend to know much of what I'm doing just trying to learn.

The car:
Forged 347, 10.5:1 compression ratio
HUGE cam (248/252 .61x/.61x 110 + 6 LSA)
Patriot 243 heads
Fast 90/90
LT's, X-Pipe, etc.
Twin Walbro 255LPH
Fuel Pressure: 58 PSI

NOTE: I realize these injectors are WAY too big for the car on motor at the moment, I've been piecing together an e85 turbo setup for a while until my wife peed on a stick, got a smiley face and put my wallet on no questions asked lockdown!

Right now I'm messing with it on pump gas, not E85. I actually had the car lined out really well on the last fuel system which was single walbro, stock feed line, Lucas 42.5lb injectors...Only thing changed from then to now is Dual Walbro, Motron 80lb, 8an feed w/ stock feed as the return, Aeromotive FPR....

I changed the injector calibrations to what I found on this board for those injectors, so I have no idea how close they are, but I thought that the computer should automatically compensate the tune and put me pretty close, and it did at idle, but not anywhere else. I'll attach the most recent tune I flashed to it and I'm sure there are 230523508 things wrong w/ it, so please help and sorry for writing such a book!

[hardrock21]

These injectors are rated 80lb @ 3bar....Some people have mentioned to me dropping the base pressure down to 43.5 instead of the 58, I've also read some about the transient fuel adjustment to get the pulse width down, if that's the problem.

[hardrock21]

If a mod could please move this to the appropriate section I would appreciate it. Thanks and sorry.

[hardrock21]

Come on, help a rookie out! Will dropping the pressure change anything or is my tune just way off?

[Nodnarb]

Try the attached. Im assuming your FPR is vacuum referenced.

[hardrock21]

Try the attached. Im assuming your FPR is vacuum referenced.

Thanks! I don't have the Vac line hooked up to the FPR at the moment..It's no big deal to do so though. Would it make a difference? Thanks again for the help!

Paul

[Redline MS]

The issue is less that they are too big and more that they are horrible injectors..you could be running a 200 lb/hr injector and as long as you have control over it it really doesn't matter.

We have flow bench tested many sets of 80s and found them very inconsistent in static flow and real bad at low pulse widths..I'm not saying you might not have something else going on but dont rule this out.... Just mine and a few others experiences being voiced.

Howard

[Nodnarb]

Use this one if you don't hook up the vacuum line.

And I'll agree with the above statement.

[jakebdb56]

The issue is less that they are too big and more that they are horrible injectors..you could be running a 200 lb/hr injector and as long as you have control over it it really doesn't matter.

We have flow bench tested many sets of 80s and found them very inconsistent in static flow and real bad at low pulse widths..I'm not saying you might not have something else going on but dont rule this out.... Just mine and a few others experiences being voiced.

Howard

Couldn't agree more. The cheaper 80's can work, but aren't optimal. Being a dinosaur technology injector doesn't help in this situation.

[hardrock21]

I see... well if I can't get them lined out, I will just have to go with another injector I suppose. Aren't they pretty similar to the Siemens deka 80 lb? I wonder why they sell them if they are such crap.

[99VetteFRC]

I just bought the seimens-dake 80#ers and put them on my car and at 34.5 psi they run ok. I just changed a couple tables, not perfect but ok till I get it tuned.

[hardrock21]

A few people have recommended that I turn the base pressure down. I may try that, I was just concerned I had incorrect injector data entered. When I get the chance, I am going to try flashing the tunes from this thread and see how it does

[jakebdb56]

There's really not "good" LS data for these for that pressure, but you'll have to work with it. Turning the base pressure down is fine, but you MUST run a boost referenced regulator if you do so. Your mean effective pressure would go down the drain and render the injector useless. I don't really have data for these, or else I would share some insight to help you get started. If they're the older big body ones then your minPW will probably be around 1.08

[hardrock21]

There's really not "good" LS data for these for that pressure, but you'll have to work with it. Turning the base pressure down is fine, but you MUST run a boost referenced regulator if you do so. Your mean effective pressure would go down the drain and render the injector useless. I don't really have data for these, or else I would share some insight to help you get started. If they're the older big body ones then your minPW will probably be around 1.08

Thanks for the help, I don't have my HPT Laptop in front of me, but I think 1.08 sounds about what the guy earlier in this thread changed the values to in my tune so I'm going to give that a shot when I can. I bought the injectors from speed inc. a few months ago so I'm not positive how to tell if they are the "older big body ones." Thanks again.

[LSxpwrdZ]

I've not had ANY issues with any of the siemens-dekka/mototron 60's or 80's in EV6 form. The short injector's IMO are about junk but all the EV6 body injectors I've used have all worked out awesome and drive like stock in all the applications I've tuned them in.

Proper injector calibration data is key obviously as it is with any injector. Definitely hook up the vacuum line to the regulator. That will take out one more obstacle in the calibration data.

[racerx203]

Thanks for the help, I don't have my HPT Laptop in front of me, but I think 1.08 sounds about what the guy earlier in this thread changed the values to in my tune so I'm going to give that a shot when I can. I bought the injectors from speed inc. a few months ago so I'm not positive how to tell if they are the "older big body ones." Thanks again.

Dealing with speed inc is your first mistake. Hope you get it straighten out. Good luck

[hardrock21]

I've not had ANY issues with any of the siemens-dekka/mototron 60's or 80's in EV6 form. The short injector's IMO are about junk but all the EV6 body injectors I've used have all worked out awesome and drive like stock in all the applications I've tuned them in.

Proper injector calibration data is key obviously as it is with any injector. Definitely hook up the vacuum line to the regulator. That will take out one more obstacle in the calibration data.

Are you able to compare the injector data I have in my tune w/ the data you use for the 80lb injectors? I still haven't gotten a chance to get down there and try anything different. I am for sure going to hook up that vacuum line though. Also, would dropping the base pressure help at all or should I just keep trying to line them out at 58psi? Thanks for all the help!

As far as Speed Inc., I've never had any trouble w/ them and I've ordered quite a bit from them over the years. I'm sorry you had a bad experience w/ them.

Paul

[blownbluez06]

I just bought the seimens-dake 80#ers and put them on my car and at 34.5 psi they run ok. I just changed a couple tables, not perfect but ok till I get it tuned.

If you've got your fuel pressure that low on a C5 Vette, be mindful of the balance in fuel levels between your 2 tanks because I would be surprised if it didn't throw it off and prevent you from emptying the passenger tank. If it does cause a problem, turn the pressure back up and it'll go away.

[hardrock21]

Alright, finally was able to spend a minute down there. I got the FPR hooked up to Vacuum and the Vac reference tune from this thread loaded. It seems to at least be allowing me to line it out much better then it was. I'm just working on the cruising for now, it's a handful to drive and it's 102 degrees out today so I didn't spend a whole lot of time logging it. I'll attach one of the logs and the final tune after 2 adjustments to the VE.

Can someone please help me figure out how to get my Lambda_err PID to accurately display and get it to log in the histograms correctly? Do I need to attach my config file for that?

[hardrock21]

One more question. When setting the fuel pressure relative to vac, how should I go about that... Should it be set at 58psi at 0kpa so it drops to 53ish when pulling vac or should it be 58psi when pulling vac and jump to 64ish at 0kpa? Thanks