Big Problems With Kenne Bell Fuel System and FRPP 80lb Injectors

[Rickyll7]

Your short (and long, for that matter) trims are right around 1 which tells me the PCM isn't having to grossly account for the undersized 24# injector squirts if the calibration is loaded for 80# injectors.

That is, it still appears to me that the PCM thinks there are 24# injectors and when there are, the trims are right where you'd expect them to be. If you've got the 80# calibration in there then I suggest again that no, you don't have that loaded no matter what you think or what the SCT is saying.

Take the car to a proper dyno tuner (set the valet bypass on the blower and drive with the 24# injectors in it...) and have them assess the scalars.

The data logged values I posted above are with my 24 lb injectors and the ecu tuned for those injectors.

 

[tonytaylor85]

boost-a-pump on a return style system I guess as long as the fuel pressure is in line it's OK.
Did the kit came with 36# units? Have you tried those or did you pass on the KB sourced ones?
I hate to be on a bandwagon but 80#/hr seems huge. Do they even make a bigger injector?

 

[Gearbanger 101]

You new 80lb/hr injectors are of High Impedance design, are they not?

 

[Rickyll7]

You new 80lb/hr injectors are of High Impedance design, are they not?

Good question. They are high impedance. Check out the website below.

Ford Racing Performance Parts []

 

[trinity_gt]

The data logged values I posted above are with my 24 lb injectors and the ecu tuned for those injectors.

What's the purpose of this test? You said the car runs perfect with the 24s: Why not log the thing with the 80s and the 80 scalars?

 

[Rickyll7]

The purpose was to determine exactly where the problem was. Now I know without a doubt that it's the injectors or the values for them.

I would like to do more data logging with the 80s, but it's running so poorly, that I don't want to run it too long.

 

[Rickyll7]

boost-a-pump on a return style system I guess as long as the fuel pressure is in line it's OK.
Did the kit came with 36# units? Have you tried those or did you pass on the KB sourced ones?
I hate to be on a bandwagon but 80#/hr seems huge. Do they even make a bigger injector?

Bigger injectors than the 80s are made, but I don't know if FRPP makes any.

I haven't tried the 36 lb injectors that came with my kit. I don't have any tuning values for those and they are too small for my hp goals anyway.

I may settle for the 60 lb injectors if I can't get the 80s to work. The 60s will at least meet my hp goals for this blower, but they will probably fall short (or at least come dangerousely close) if I upgrade to the 2.6L, unless I increase the fuel pressure, which I would rather not do.

However, as I said before, I don't want to spend any more money on injectors until I figure out this problem. Otherwise, I could end up with the same issue with the new smaller injectors and have wasted my money.

 

[Trav4011]

There is absolutely nothing wrong with running the FRPP 80lb injectors.. For those saying that it's too big of an injector.. I run them in a Lightning, with no problems whatsoever. It doesn't matter how big of a blower you have.. It won't change the injector charcteristics at idle/partial throttle. While it may be overkill for the blower that you're currently using.. that doesn't mean that you shouldn't be able to get it dialed in.

The 80lb injectors are big injectors, though.. and my truck required a few hours of dyno tuning to get it perfect. Preset values may/may not cut it for your exact application. You're just going to have to mess with the fuel tables until you get it right.

Travis

 

[Trav4011]

One other thing.. Make SURE that you have fresh primary o2 sensors installed.. as getting the car to idle/rev in closed loop, properly.. will require fast and accurate feedback from your o2 sensors.

 

[trinity_gt]

There is absolutely nothing wrong with running the FRPP 80lb injectors.. For those saying that it's too big of an injector.. I run them in a Lightning, with no problems whatsoever. It doesn't matter how big of a blower you have.. It won't change the injector charcteristics at idle/partial throttle.

Well it will in that the PCM shortens the IPW for every closed loop situation. For example, if a 19# injector required a 1mS pulse at idle in sequential mode, the 80# injector will, by definition, require roughly 1/4 of that IPW or 250uS. You can see that at what are already low IPWs for 19# becomes almost impossibly low for very large injectors. Those injectors have a minimum specified MINPW of 599uS at 39psi.

In this example, I just made up the 1mS idle value but it may indeed not be far from that and if so, the idle may be difficult to dial in if the PW commanded goes below the minimum rating for the injector.

 

[Don 95Vert]

Nothing wrong with upping the fuel pressure on 60# injectors. In fact they are rated to flow 60# at a FP of 43.5. We run a 700 RWHP (through a C4) with 60's with a base FP setting of 60 - with the Siemans-Deka 60's you could probably run 80-90 for FP if you liked. This IS OK as long as you tune for them. My own Gen 1 Turbo Lightning makes over 500 and it has 60's with a base FP of around 48 - those injectors are way ovekill for my setup. They both drive like stock. The 60's are said to have a good spray pattern and jusging from what I have seen from 50's, 55's and the 80's, I'd say either that is true or the values commanly available for the 60's have to be dead nuts on.

Keep in mind 60's with a base FP of 60 will flow a lot more and act like 82's.

Not saying you should throw in the towel just yet on the 80's though - we all have occasional problems with cars that kick our asses. Seems to me you have something else going on though - like maybe a stuck injector - seen it happen before with brand new injectors. If not, if you want, email me your file and I'll have a look at it to see if there is something glaring that you might be missing - [email protected]

Good Luck!

Don

 

[2002BLGT]

Im going to agree with Don , might be stuck injector or something , id try with the 36lbs injectors , use the 39lbs injector slope value files and just adjust the slopes to get the fuel trims in order and it should be close enough to run good , and the post back if that will fix the issue , if it does , id try to get a replacment set of injectors , or a set of 60s

 

[tonytaylor85]

Bigger injectors than the 80s are made, but I don't know if FRPP makes any.

I haven't tried the 36 lb injectors that came with my kit. I don't have any tuning values for those and they are too small for my hp goals anyway.

I may settle for the 60 lb injectors if I can't get the 80s to work. The 60s will at least meet my hp goals for this blower, but they will probably fall short (or at least come dangerousely close) if I upgrade to the 2.6L, unless I increase the fuel pressure, which I would rather not do.

However, as I said before, I don't want to spend any more money on injectors until I figure out this problem. Otherwise, I could end up with the same issue with the new smaller injectors and have wasted my money.

You will have to retune if you upgrade the blower, so keep the 80# for that and run the 36# injectors until then. They should support 460HP with no problem. What *are* your HP goals?

 

[Gearbanger 101]

They should support 460HP with no problem.

At the crank maybe (and even then you're pushing it), but they'll be seeing 100% duty cycle long before that if you're measuring it at the rear wheels.

 

[tonytaylor85]

At the crank maybe (and even then you're pushing it), but they'll be seeing 100% duty cycle long before that if you're measuring it at the rear wheels.

Forgot that FI engines use the .65 BSFC instead of the NA .50
From Ford Racing

max safe hp = [ (injector size) x (total # of injectors) x (max duty cycle) ]/BSFC
Example: The following guide is a general rule of thumb for sizing fuel injectors on an 8-cylinder engine using a BSFC of 0.50. Forced-induction engines
typically range from a BSFC of 0.55 to 0.65, with the latter value arising from the fuel enrichment necessary to keep exhaust temperatures below 1650 deg F
and catalyst temperatures below 1700 deg F.
Naturally Aspirated: (19 lb x 8 x .85)/.50 = 258.4 or approx 258 hp @ 85% duty cycle
Forced Induction @ 0.55: (19 lb x 8 x .85)/.55 = 234.9 or approx 235 hp @ 85% duty cycle
Forced Induction @ 0.65: (19 lb x 8 x .85)/.65 = 198.8 or approx 199 hp @ 85% duty cycle
Inj Flow Rate (@ 40 psid) Naturally Aspirated hp (@ 0.50) Forced-Induction hp (@ 0.65)
19 lb/hr 258 hp @ 85% Duty Cycle 199 hp @ 85% Duty Cycle
24 lb/hr 326 hp @ 85% Duty Cycle 251 hp @ 85% Duty Cycle
30 lb/hr 408 hp @ 85% Duty Cycle 314 hp @ 85% Duty Cycle
32 lb/hr 435 hp @ 85% Duty Cycle 335 hp @ 85% Duty Cycle
39 lb/hr 530 hp @ 85% Duty Cycle 408 hp @ 85% Duty Cycle
42 lb/hr 571 hp @ 85% Duty Cycle 439 hp @ 85% Duty Cycle
47 lb/hr 639 hp @ 85% Duty Cycle 492 hp @ 85% Duty Cycle
60 lb/hr 816 hp @ 85% Duty Cycle 628 hp @ 85% Duty Cycle
Remember, the above calculations assume a fuel pressure of 39.15 psid. If you can raise fuel pressure and still be sure that your fuel pump can supply the
desired flow rate, then these maximum horsepower numbers will increase.

 

[Rickyll7]

There is absolutely nothing wrong with running the FRPP 80lb injectors.. For those saying that it's too big of an injector.. I run them in a Lightning, with no problems whatsoever. It doesn't matter how big of a blower you have.. It won't change the injector charcteristics at idle/partial throttle. While it may be overkill for the blower that you're currently using.. that doesn't mean that you shouldn't be able to get it dialed in.

The 80lb injectors are big injectors, though.. and my truck required a few hours of dyno tuning to get it perfect. Preset values may/may not cut it for your exact application. You're just going to have to mess with the fuel tables until you get it right.

Travis

Do you know what kinds of changes the tuner made for those injectors? What scalers and/or tables were adjusted? Could you get any of those values from your tuner?

 

[Rickyll7]

Well it will in that the PCM shortens the IPW for every closed loop situation. For example, if a 19# injector required a 1mS pulse at idle in sequential mode, the 80# injector will, by definition, require roughly 1/4 of that IPW or 250uS. You can see that at what are already low IPWs for 19# becomes almost impossibly low for very large injectors. Those injectors have a minimum specified MINPW of 599uS at 39psi.

In this example, I just made up the 1mS idle value but it may indeed not be far from that and if so, the idle may be difficult to dial in if the PW commanded goes below the minimum rating for the injector.

I don't think I'm operating below the minimum pulse width. See the numbers I posted earlier, maybe my calcs are wrong

You will have to retune if you upgrade the blower, so keep the 80# for that and run the 36# injectors until then. They should support 460HP with no problem. What *are* your HP goals?

600 engine hp with the 2.1L and 800 ehp with the 2.6L

 

[Rickyll7]

Im going to agree with Don , might be stuck injector or something , id try with the 36lbs injectors , use the 39lbs injector slope value files and just adjust the slopes to get the fuel trims in order and it should be close enough to run good , and the post back if that will fix the issue , if it does , id try to get a replacment set of injectors , or a set of 60s

How could I test an injector to see if it's stuck open? Wouldn't the fuel pressure bleed out of the fuel rails after the fuel pump primes them? I can prime the rails to 39 psi and the pressure doesn't drop off with the 80s.

 

[Rickyll7]

Nothing wrong with upping the fuel pressure on 60# injectors. In fact they are rated to flow 60# at a FP of 43.5. We run a 700 RWHP (through a C4) with 60's with a base FP setting of 60 - with the Siemans-Deka 60's you could probably run 80-90 for FP if you liked. This IS OK as long as you tune for them. My own Gen 1 Turbo Lightning makes over 500 and it has 60's with a base FP of around 48 - those injectors are way ovekill for my setup. They both drive like stock. The 60's are said to have a good spray pattern and jusging from what I have seen from 50's, 55's and the 80's, I'd say either that is true or the values commanly available for the 60's have to be dead nuts on.

Keep in mind 60's with a base FP of 60 will flow a lot more and act like 82's.

Not saying you should throw in the towel just yet on the 80's though - we all have occasional problems with cars that kick our asses. Seems to me you have something else going on though - like maybe a stuck injector - seen it happen before with brand new injectors. If not, if you want, email me your file and I'll have a look at it to see if there is something glaring that you might be missing - [email protected]

Good Luck!

Don

I sent you my tune. Are there any values I'm leaving out? I loaded all the values from the ford data sheet, which is the same as the SCT value file for those injectors and I divided the crank fuel by 4 since the injector values didnt address those and the i divided the minimum pulse width by 2 so that the injectors will fire during cranking. How can I test an injector to see if it's stuck open?

 

[Rickyll7]

Some good info from another stang owner who is dealing with issues with these injectors. Look for boss96's post on page two.

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