28 lb injectors?

[Shaun41178(2)]

Anyone make these? Or does it go from 24-30 lb injectors?

If so anyone have 28 or 30 lb injectors?

[Shaun41178(2)]

ok I think I am going to try 30's. Anyone have any good 30's laying around?

[Aaron]

You need 42s. Oh yah baby, oh yah :thumbleft:

And if you don't need them, then crank the boost until you do!

[Pyrthian]

at them flow rates, two pounds in flow rate is a small percentage, and you can use fuel pressure to compensate alot more effectively.

[Shaun41178(2)]

You need 42s. Oh yah baby, oh yah :thumbleft:

And if you don't need them, then crank the boost until you do!

I am performing an experiment. I can't crank up the boost. There is a built in boost cut by gm. At least with my computer. It won't allow me to run past 10 psi of boost. This is the same for the tgp motor too.

I don't know where this code is at for the boost cut, so eliminating it might be harder.

It might not exist in earlier model computers like the 85. Which makes me think why the design one kit allows more then 12 psi and needing an 85 gt computer. But in my 88 it is there and won't allow more then 10

The 42's I have would be way too big for only 10 psi. My 24's are maxed out at 10 psi of boost. I am looking to go about 20% bigger and that should support 14-15 psi and a small shot of nitrous

Also I am looking for bigger injectors to perform a little experiment with to allow me to try to run more boost with my current ecm and chip.

[Aaron]

Send Darth the chip and $50. I know it's possible to eliminate the boost cut in the TGP code, as I've driven a TGP at 16psi. Boy what a drive that was!

[The Dark Side of Will]

You need 42s. Oh yah baby, oh yah :thumbleft:

And if you don't need them, then crank the boost until you do!

I am performing an experiment. I can't crank up the boost. There is a built in boost cut by gm. At least with my computer. It won't allow me to run past 10 psi of boost. This is the same for the tgp motor too.

I don't know where this code is at for the boost cut, so eliminating it might be harder.

It might not exist in earlier model computers like the 85. Which makes me think why the design one kit allows more then 12 psi and needing an 85 gt computer. But in my 88 it is there and won't allow more then 10

The 42's I have would be way too big for only 10 psi. My 24's are maxed out at 10 psi of boost. I am looking to go about 20% bigger and that should support 14-15 psi and a small shot of nitrous

Also I am looking for bigger injectors to perform a little experiment with to allow me to try to run more boost with my current ecm and chip.

What computer and code mask combo are you running?

The advantage of the '85 computer is that it has knock sensing. It did not have boost sensing stock any more than any other Fiero computer had.
Boost sensing in the computer is a very different beast than boost *control* in the computer.

[Shaun41178(2)]

I am running the 88 v6 ecm and wht I think is the $24 mask. Eitehr that or its the $24a.

I can't keep the years right. One of them is for the 88 and one is for the 85. I have to look at my notes which are not in front of me but my brain wants to say I am running the $24

I don't care about the knock sensor feature so much and I am not going to have it enabled. I just want this damn boost cut eliminated. I know IRM allows their kits if I am not mistaken to run 11+ psi as SCCA fiero on this board has a picture of his setup at 14 psi.

Its actually cutting fuel so the car shuts off. So I guess its a fuel cut and not a boost cut. But either way the car falls on its face if I try to hit 11 psi+

I talked to Ryan and I beleive he knows where its at in the TGP but where in the fiero code is another story. I haven't dissected it to look. If someone has the code they want to send me then fine I will take a look at it but right now I don't.

TGP code is set at 10.32 from what I have read. Which is right where I am stuck at.

I am going to try this to try and narrow down the problem with this fuel cut issue. If I go to this new chip and it still cuts out, then its obvious there are otehr issues. But as of now I have it narrowed down to the chip/ecm being the problem.

[The Dark Side of Will]

That sounds pretty strange. How are you controlling boost? Do you have an aftermarket boost controller or do you have a waste gate solenoid wired to the ECM?

Let's clarify some things:

Boost-aware: MAP tables have been scaled to read 2 bar of MAP with a 2 bar MAP sensor or 3 bar of MAP with a 3 bar MAP sensor and the appropriate sensor is used. The only thing this does is make sure that the ECM understands the engine's true air intake and can fuel it accordingly.

Boost controlling: ECM has electrical output, PID algorithms and accessible tuning variables to operate a waste gate solenoid to provide closed loop limiting of manifold pressure, shaping of pressure rise curve, etc.

www.tunercat.com lists the $24 as being for 86-88 Fiero V6 and the $24A as being for '85 Fiero V6. AFAIK, the Fiero code masks do NOT offer boost control...

So what's controlling your boost? Do you have a boost-aware ECM or are you tuning for boost using only your SAFC?

[Shaun41178(2)]

I have a 88 ecm with a chip done by ryan to know that there is boost. So the computer is aware that there is boost.

I am using a 2 bar map in conjunction with the chip that is programmed to see positive pressure.

I am using a manual boost controller. Its not electronic, and boost isn't being controlled via the computer with a wastegate solenoid. Its just a ball and spring boost controller. Cheap stuff.

Stock wastegate spring is at 7 psi. With no boost controller it hits 7 psi. I use the controller to dial in more boost.

Whats controlling my boost? My wastegate spring and my boost controller.

Right now I am at 10 psi ish. This is verified by my voltage that my map is seeing. So I am right under the threshhold of it cutting out.

Now what the safc does is allows me to fine tune the fuel curve based on load, throttle position. It pulls fuel, or adds fuel by modifying the signal to the computer by the map sensor.

So the safc takes the map signal, and with 0 correction, it sends the exact signal from the map to the computer.

If I pull 10% of the fuel using my safc, then it tricks the computer by saying I am running less boost then I really am. if I add 10% more fuel, it tells the computer I am running more boost then what I really am.

Now since I am right at the threshold, what I did was I set in a 0% correction factor on my safc. Went for a drive and the boost held and the car pulled all the way to the top of 4th. I tried adding around 2-3% fuel, thus thinking the computer was seeing more boost then it really was. So even though I was still at the same wastegate setting, the computer thought I was running more then 10 psi.

What happened by adding 3% more fuel cut my car off and it fell on its face. So I know its not a spark issue, or anything like that. Its a fuel cut issue in the computer from seeing too much boost. I guess its protecting the motor and it makes sense.

When I pulled the 3% of added fuel and went back to 0 correction on the very next pull not 15 seconds later, the car pulled all the way till the top of 4th again.

So by changing how much fuel to add, I tricked the computer into thinking I was running more boost then I really was, thus shutting my car down.

Now with my old setup I never had this problem. I was actually pulling about 8-10% of fuel making the computer think I was actually running less boost. I would normally run 11-12 when racing.

I think one reason why I didnt' have this prob on the old motor is that it wasn't as efficient as this new motor. I am getting more air into the cylinders via better heads and cam. Because of this I am now running lean even with 0% correction. Whereas on the old motor like I said I pulled about 8% or so. So now when I try to add fuel, it thinks I have more boost when I really don't shutting the car off.

I am hoping by going to the $24a mask I can bypass this fuel cut safety issue.

Of course another trick which I thought of doing is by going with slightly larger injectors, and then dialing them back with the safc, thus allowing me to run more boost without hitting the fuel cut.

Any of this make sense?

[CincinnatiFiero]

What ECU are you running? Stock 88? If so talk to ryan about the 7730 ECU swap, updates 10 times faster than the 88 Fiero ecu and has a built in knock sensor. I picked up a ecu, chip, and pigtails for $27 at a junkyard, and ryan will build you a chip for $50. I sold my ecu on Old Europe to someone for $80 so I haven't swapped yet.

[The Dark Side of Will]

Any of this make sense?

You've described it well and done very good troubleshooting, but it still doesn't make any sense... more later.

[Honest Don]

98 LS1 engines use 28lb injectors, 99-02 use 26lb'ers. try the for sale section on ls1tech.com. Also ford svo green tops are 30lb'ers (possibly the red tops, I get them mixed up). both should fit your motor

one question, if you only have to make a small jump, why not just increase fuel pressure?

[Shaun41178(2)]

Red tops are 30's green tops are 42's.

I already have a set of 42's but no sense in using them since I can't run more boost.

I tried increasing fuel pressure from 39 to 43 and still no change.

The injectors are maxed out.

I think the ls1's have a different connector then what we use. I might be wrong on that though

[The Dark Side of Will]

The only way I could see that you would have issues with a fuel cut at a certain boost threshold would be if the VE tables are zeroed above that boost level. Your FPR is boost referenced, so there shouldn't be any problems with fuel pressure holding the injectors closed (running stock fuel pressure?). I wonder if there's an obscure calculation in the code someplace that estimates engine load or airflow and that is being maxed out and rolling over, resulting in zeroing the calc'd airflow and injector pulse.

Just convert to 7730 and run TGP code.

[whipped]

yeah, I'm confused as well.

Is it that you're maxing out the tables? Need a 3 bar chip/sensor?

If the ECM isn't controlling boost, what's the problem?

[Shaun41178(2)]

Still running stockish fuel pressure. Its been at 39 but I bumped it to 43 lately.

The problem is that the computer isn't controlling boost, but it knows how much I am running based on the map signal. It hits too much boost, and its cutting fuel.

If there is a problem in the VE tables then thats out of my control. Its int he chip and going to have to ask Ryan about that.

the VE tables I know go up to 4800 rpm. THe problem occurs well before that. Usually 4k rpm or so. Sometimes sooner pending on what gear I am in and what rpm I start at. 14 psi by 3500 rpm is possible, it spools quick

I am not ready to spend the time to convert to 7730 yet. It doesn't need to be converted. I have the harness and computer to do so but not in the mood. It can be figured out. I think Ryan said he has never done an 88 chip before so I am sort of in unchartered territory here. I am just ready to ditch this 88 and see if the 85 ecm will work. If it doesn't then I will figure something else out, or just run more nitrous.

[whipped]

the POS fiero computer was never meant to run boost. I think that's your problem. :la:

[Honest Don]

Red tops are 30's green tops are 42's.

I already have a set of 42's but no sense in using them since I can't run more boost.

I tried increasing fuel pressure from 39 to 43 and still no change.

The injectors are maxed out.

I think the ls1's have a different connector then what we use. I might be wrong on that though

I'm 90% positve that they use the same connector. I'll find out for sure by this weekend though.

how nice is your fuel pump? If it was me, I'd see what 55psi+ would do.

[The Dark Side of Will]

I am not ready to spend the time to convert to 7730 yet. It doesn't need to be converted. I have the harness and computer to do so but not in the mood. It can be figured out. I think Ryan said he has never done an 88 chip before so I am sort of in unchartered territory here. I am just ready to ditch this 88 and see if the 85 ecm will work. If it doesn't then I will figure something else out, or just run more nitrous.

Are you the one who's always busting on people for not getting their stuff tuned right?

Why doesn't that extend to getting the right engine management to tune stuff right?

IE, shouldn't you be taking your own medicine? :thumbleft: