SVO 42lb (Green Top) Fuel Injectors

[Tordne]

So I finally got around installing my SVO 42lb injectors the other night and am wondering if anyone out there has come across a magical combination of tables (offset, default & min pulse width, small pulse adjust etc)?

I have been experimenting a bit and have discovered that the offset and small pulse adjust tables make a HUGE difference. One offset table would see me with 19+ AFR (no this is not DFCO) at low load. Another offset table has me really rich, like 11-12 AFR. Higher load seems to be a lot more stable...

These are a little big for my car (stock internals) but I think I had a fouled injector so decided to change them over. They seem to be OK etc. at idle so I expect that if I can find the sweet spot in the combination of these tables it will be all good :)

:help2:

Cheers,

[Redline Motorsports]

I have a couple projects coming up that we are using the green top 42's on and would like some "heads up" info as well. I am still trying to understand the offsets and there effect on overall performance. Many who have been playing with seem to also see rewards in some adjusting.

Are the adjustments made globally on the whole table? Are you just adding or subtracting percentages overall?

Hope we get some info!!!:master:

[Tordne]

The only columns that I've hit in the offset table are the 13, 13.5 and 14 volt columns, which I guess is a good thing :)

I think when I was running really lean down low (the offset table values were much lower than the current table) the final pulse width was just too low to allow for the injector opening time, fuel delivery etc and that basically no fuel was actually being delivered.

Both the offset and the small pulse tables make a staggering difference!!! I tried making a MAP of the offset table and thought I might be able to use the BEN factor and a means of adjustment. But, the variance in BEN factors is too wide IMO.

[redhardsupra]

i love svo 42s mostly because it doesn't take anything magical to get them going right ;)
use the injectors.xls spreadsheet to do IFR table, if you use 42@43.5psi for ratings, and use the fuel pressure of your setup for the final calculation.
stock voltage offsets works fine.
as for the minimal pulse width, i've taken it down to 1.0 but it didn't seem to make much difference.
if your car was tuned well before, and the injectors flow close to the advertised numbers, you should not need a retune.

[Tordne]

Mate LOL

The offset table makes a huge difference and the stock table from different vehicles is quite different.

I thik with these larger injectors the offset values have to be sufficient for the injector to actually open and supply fuel. The 14 volt column of the offset table I'm using (which is the most common column hit) at high vacuum (low map) is ~ 50 - 52. This gives me BEN factors of 0.86. If I use another stock offset table that has values in the offset table of 33 the BEN factors are 1.33 (max that my WB goes to) - this is 19.5+ AFR :Eyecrazy:. All other tables remain the same. So, that is a good example of the variance just the offset table can make...

I'm experimenting with lowering the Default Minimum Pulse Width (B4004) table, as is stock in some tines. So far it looks like it might yield good results.

Cheers,

[Dirk Diggler]

I slapped my 42's in scaled the IFR table and went about my business. Ive tried to figure out the offset table a few times but no one wants to talk about it

[Bruce Melton]

829
I did this swap recently and used RHS sheet but found a range of assumtions for SVO fuel pressure. The attached values turned out to be closer to perfect than I ever hoped for.

[minytrker]

I just put SVO 42s in my car, I did the mulitplying method to rescale and had no issues. Its nie now not to see over 100% duty cycle.

[redhardsupra]

Tordne: I know it makes a difference, but it's hard to argue with many empirical cases of putting them in, chaning IFR and being taken care of. If I saw a problem I'd address it, but they never gave me the slightest problem so I'm not gonna go looking for one.

DirkDiggler: I still wanna talk about it... I think we oughtta measure resistances of stock vs svo 42s and adjust the voltage offset table according to Ohm's law for starters.

[Dirk Diggler]

Yeah i would like to do that also. That is what i proposed a while back but no one listend :(

[eboggs_jkvl]

I found a small problem with the 42 SVOs. They really get grumpy at IPWs of really short duration. I chased a friggen "miss" or "lurch" at low speed low throttle conditions and found the injectors themselves were the culprit. I changed to Delphi 42s and the problem went away. I thought I'd mention it as the problem was a bear to find. Normal driving, acceleration, WOT, all of that was perfect but driving in the housing plat, say in 2nd gear and running 15 to 20 MPH (Gotta watch out for the kids) and the car would toss a darn lurch in rather than just rolling along at a smooth run.

I think THunder Racing stopped endorcing the SVO 42s just for that precise reason. Just an FYI.


Elmer

[joecar]

RHS,
DD,

I'm not changing my injectors for now, and I don't have any spare ones lying around to measure and play with, but I'm interested in your findings; keep this me posted, I'll follow along.

:cheers:

[Dirk Diggler]

I mesure the stock and I think they were 16.9 ohm the svc 30's were 13.3 or something like that but i nver went further than that

[Tordne]

OK. So I played more with this.. And if my drive to work (in a few mins) is successful I'll be able to shed some light on this subject :)

My BENS after the swap were prefect (using your sheet RHS). The ONLY problem is very low MAP, < ~20 kPa. Remember I have these in a stock internals car right now so perhaps there is something in that.

Anyway, another post soon hopefully :)

[Bruce Melton]

I found a small problem with the 42 SVOs. They really get grumpy at IPWs of really short duration. I chased a friggen "miss" or "lurch" at low speed low throttle conditions and found the injectors themselves were the culprit. I changed to Delphi 42s and the problem went away. I thought I'd mention it as the problem was a bear to find. Normal driving, acceleration, WOT, all of that was perfect but driving in the housing plat, say in 2nd gear and running 15 to 20 MPH (Gotta watch out for the kids) and the car would toss a darn lurch in rather than just rolling along at a smooth run.

I think THunder Racing stopped endorcing the SVO 42s just for that precise reason. Just an FYI.


Elmer

I would think they are loafing badly at idle and low rpms. Mine are only @ 71% max. I know they flow like crazy cause my fuel milage as gone to hell with this 402.

[eboggs_jkvl]

I would think they are loafing badly at idle and low rpms. Mine are only @ 71% max. I know they flow like crazy cause my fuel milage as gone to hell with this 402.


Exactly the problem. MY turbo setup is a pure "stock" type of setup as far as engine demands A/F and the like, until you go to boost. I need the large injectors at WOT but the darn car is not running at WOT when I am doing 20 mph, 2nd gear and .7v on the TPS. The injectors lurch and stumble. Right now I have 60 pound injectors and I've detected the same problem but I know there isn't squat that I can do about it as I need all I have to handle my WOT situations.

Elmer

[dfe1]

I have a good friend in the injector cleaning/blueprinting business. If anyone has a spare 42-pound SVO injector, I'll get him to flow test it at various pulse widths. We can build a flow rate versus pulse width table and perhaps shed some light on the low pulse width issue.

[Dirk Diggler]

If you cant find a person in November or so i will donate mine for testing

[Chuck L.]

I have a good friend in the injector cleaning/blueprinting business. If anyone has a spare 42-pound SVO injector, I'll get him to flow test it at various pulse widths. We can build a flow rate versus pulse width table and perhaps shed some light on the low pulse width issue.

Not sure if these "SVO"s' are a Lucas inj, or ??
FWIW, the "old" green stripes, that were popular in the turbo Buick realm, were not real "nice" to tune, especially at idle....[But, then the old ECM 's are alot less than sophisticated].:D

Inj part # is??

[Dirk Diggler]

My green top 42's have delphi stamped on em even though they were dubbed svo 42's

[Chuck L.]

My green top 42's have delphi stamped on em even though they were dubbed svo 42's

Dirk, is there a part # on them?? The Delphi # may start w 1710XXXX.

[Bruce Melton]

I just looked at mine:
Lime green and I thought made by Bosch? >>http://www.fiveomotorsport.com/Injector_SetsMODS.asp
One one side:

Ford logo then XL3V-A9A

other side:

486-280150558

[Dirk Diggler]

Maybe they are Bosch. Delphi is usually Racetronix. I may be wrong

[TAQuickness]

dirk - if you got yours from the same place i did, i would bet they are bosch.

[Dirk Diggler]

dirk - if you got yours from the same place i did, i would bet they are bosch.



Bosch it is!!!!!! The Delphis I had were racetronix

[Chuck L.]

I just looked at mine:
Lime green and I thought made by Bosch? >>http://www.fiveomotorsport.com/Injector_SetsMODS.asp
One one side:

Ford logo then XL3V-A9A

other side:

486-280150558

right, Bruce. The pt# is a Bosch #. The poor idle symptoms of the "old" green stripes, [not green tops] does not apply to these..These should be a good part to work with.:)

[Bruce Melton]

right, Bruce. The pt# is a Bosch #. The poor idle symptoms of the "old" green stripes, [not green tops] does not apply to these..These should be a good part to work with.:)

You make me happy, but throw my low range drivability problems back in my lap :)

[TAQuickness]

I mesure the stock and I think they were 16.9 ohm the svc 30's were 13.3 or something like that but i nver went further than that

I don't have a stocker to measure, but I just measured my SV42's and they are 14.5

[Dirk Diggler]

my stockers were like 16 or 16.5 ohms i cant remember

[Tordne]

Can people with these injectors post up what there minimum pulse width is in their logs please?

I'm thinking that there is a hard minimum that if commanding below just has the injector not opening!

I think there is a delicate balance of Default/Minimum Pulse Width, Offset and Small Pukse Adjust required. And I really like to see what you others are doing :)

Cheers,

[redhardsupra]

i've always seen it hit about 1.7-1.9msec, for both 30s and 42s, that's what i have the most experience with, so that's all i'm gonna speak of. changing minimum/default pulse widths doesn't have much impact that i've seen.

My question to the peanut gallery is: Upon decel, do your fuel trims go rich? It hits the pulse width minimum but it doesn't seem to be small enough, and STFT's go rich. I've seen it happen on everything from 30s to 60s and I wonder why.

[Tordne]

I've found that changing the Default/Minimum from 1.28 to 1.26 will cause me to jump from being lean, like 19.5+ AFR (injectors not opening at all i suspect) to being rich in the ~12-13 AFR's.

I've tested repeatedly, trust me :)

My min pulse width seems to be around 1.75ms BTW.

Cheers,

[Dirk Diggler]

It hink i see anywhere between 1-2 ms but I am not stock either

[Bruce Melton]

With the SVO lime greens:
Idle log ~1.5-1.6
PE tuning logs as low as .450-- I think this is decel.
402ci.

[Tordne]

Installed my stock injectors again today as I was just using WAY TOO MUCH fuel in my low map areas. The SVO 42's are just too big for stock motor.

Should have got the SVO 30's, but I bought these when I was planning on doing a 408 replacement motor :frown:

Interestingly throttle transitions feel a lot better with the stockers, I guess it is not being flooded with fuel which is probably the cause...

[Bruce Melton]

Installed my stock injectors again today as I was just using WAY TOO MUCH fuel in my low map areas. The SVO 42's are just too big for stock motor.

Should have got the SVO 30's, but I bought these when I was planning on doing a 408 replacement motor :frown:

Interestingly throttle transitions feel a lot better with the stockers, I guess it is not being flooded with fuel which is probably the cause...

I would agree SVO42s (53s) are just too big for NA346s. They just can't cope with being throttled back to near nothing at the low demand end.
I think mine are lazy with 402.

[redhardsupra]

nope, they're perfectly fine in near stock application. i have logs of my friends 01 SS with nothing more than filter, exhaust and mac mids. then we put on the injectors in preparation for later cam. i can post it if you're interested.

[TAQuickness]

post it ;)

[Bruce Melton]

nope, they're perfectly fine in near stock application. i have logs of my friends 01 SS with nothing more than filter, exhaust and mac mids. then we put on the injectors in preparation for later cam. i can post it if you're interested.

I don't need proof they work. My experiece is they work but are inconsistant at low flow. I am using your IFRs, so don't take offense, but logic says you can't get great control of a firehose to fill a teacup.

[TAQuickness]

I don't need proof they work. My experiece is they work but are inconsistant at low flow. I am using your IFRs, so don't take offense, but logic says you can't get great control of a firehose to fill a teacup.

:muahaha: I've seen this in my logs. But - it was of minor concern.

[eboggs_jkvl]

I don't need proof they work. My experiece is they work but are inconsistant at low flow. I am using your IFRs, so don't take offense, but logic says you can't get great control of a firehose to fill a teacup.

WERD! They are great except at low flow. THey stumble or "miss" when the IPW goes below 1 ms or so.


Also, my experience says large injectors are fine if they can take the low flow conditions. My 60# are borderline at light load but perform admirably in city driving and WOT.


Elmer