Data logging questions?

[ninerscout]

I have a 1227747 computer. I am using $42-1227747-V4.1.xdf‎ and $42-1227747-V4.1.adx‎. My Injector Duty Cycle %, BPW MS from hack *, and my Spark Advance From hack are in Red. Am I doing anything wrong? my data log and Bin is attached.

Thanks,
Ninerscout

[ninerscout]

So I decided to check my fuel pressure with a Mac Tools gauge and compare it to a gauge I bought from CFM Technologies. The gauge from CFM Technologies was totally different from my Mac Tools gauge. CFM Technologies gauge reads 13 psi and my Mac Tools gauge reads 17 psi. I am guessing this is why my readings are off on Tuner Pro. I bought a Fuel pressure regulator from CFM Technologies and I can not get it to drop bellow 17 psi. So can I run my TBI at 17 psi? Maybe change my BPW? Will I have problems with this high of pressure? I took it out and it runs good. I am getting close one my VE tables. I am running a stock International 345 with stock TBI , 65lb injectors, tri wye headers, fuel and spark control.

Thanks,
Ninerscout

[EagleMark]

In the XDF file under Scalers there are three **Read Me Hack**. You did not apply them to the bin before you did your data log, so those data items will not work.

Those three hacks take the place of Prom ID, Old pa3 and O2 Cross counts in ADX/data output. So what this does is changes the bin to put out more useful information in data stream.

Looked at your BLM and looks like you got the hang of using the spreadsheet, they are looking good! :thumbsup:

[EagleMark]

So I decided to check my fuel pressure with a Mac Tools gauge and compare it to a gauge I bought from CFM Technologies. The gauge from CFM Technologies was totally different from my Mac Tools gauge. CFM Technologies gauge reads 13 psi and my Mac Tools gauge reads 17 psi. I am guessing this is why my readings are off on Tuner Pro. I bought a Fuel pressure regulator from CFM Technologies and I can not get it to drop bellow 17 psi. So can I run my TBI at 17 psi? Maybe change my BPW? Will I have problems with this high of pressure? I took it out and it runs good. I am getting close one my VE tables. I am running a stock International 345 with stock TBI , 65lb injectors, tri wye headers, fuel and spark control.

Thanks,
NinerscoutThat's a delema with fuel pressure gauges, you don't know what is accurate? Your BLM look good in that last data log so go with whatever pressure that was and do some WOT high RPM to see if you run out of fuel. If you run low on fuel/BLM going lean and can not adjust VE high enough then you need more pressure.

For the IH motor 13 PSI should be fine.

Did the adjustable regulater come with spring? It may not be able to go lower then 17 psi?

Or if you have a restriction in return line it will raise pressure on feed side.

[PJG1173]

So I decided to check my fuel pressure with a Mac Tools gauge and compare it to a gauge I bought from CFM Technologies. The gauge from CFM Technologies was totally different from my Mac Tools gauge. CFM Technologies gauge reads 13 psi and my Mac Tools gauge reads 17 psi. I am guessing this is why my readings are off on Tuner Pro. I bought a Fuel pressure regulator from CFM Technologies and I can not get it to drop bellow 17 psi. So can I run my TBI at 17 psi? Maybe change my BPW? Will I have problems with this high of pressure? I took it out and it runs good. I am getting close one my VE tables. I am running a stock International 345 with stock TBI , 65lb injectors, tri wye headers, fuel and spark control.

Thanks,
Ninerscout

65# injectors @ 17 psi is alot of go go juice. Id get a third opinion from another gauge.

[ninerscout]

The adjustable fuel pressure regulator did not come with a new spring. I reused the original spring in the Throttle body. I will check for a restriction in the return line. I will try another gauge. I have a liquid filled that should be pretty accurate. Thanks a lot guys.

Ninerscout

[EagleMark]

He got his BLM pretty perfect, and with a stock spring your not going to get 17 PSI so I would believe the other gauge that says 13 PSI for now and stay there. Could see if that gauge will go up and down a little from 13 PSI. But I'm leaning to the MAC gauge being wrong at 17 PSI...

[ninerscout]

I know I am dwelling on fuel pressure too much but I know it is the base of the system. something the computer does not see. So I played around with the adjustable regulator, bumped up the pressure too high, and burried my gauge from CFM Tech and ruined it. Costly mistake. I tried three other gauges and received different results. So I put the original regulator in. Still getting 17 psi. with the Mac gauge, which should be the most accurate, and 6 psi with a liquid filled. On the Mac gauge I am using a OTC adapter that goes where the stock Chevy fuel filter is. The liquid filled is right at the inlet of the throttle body. I know the stock regulator is set around 13 psi. but I bumped it up when I had it removed. I twisted it till the Tab was half way. Runs great, so I am going to run it. If I am thinking correctly the pressure being too high it would run really rich and the BLM table would reflect it. Is that correct? Anything else am I missing about running too high of pressure.

Thanks,
Ninerscout

[EagleMark]

Fuel pressure is important. But you can't get good overall results in tuning with pressure adjusted to who knows what. At this point you would be better with the stock spring and regulator.

Pressure should be same at fuel filter on stock chevy truck as gauge is made for or at TBI inlet. Hot oil filled gauges are known to be off when hot but I have never had that issue with cheap gauges... yet, others have.

I would think the MAC would be the most accurate but it is also a commercial tool and may be overused, broke or just out of calibration. IIRC a stock spring will only get 15PSI. MAC gauge says 17? Also what is the scale on MAC gauge? If 0 to 30 it's way more accurate than 0 to 75. Now lets say it is accurate and you do have 17 PSI then you have a problem! Either bad regulator or restriction on return line. Restriction is easy to find, just run a hose from return into gas can and check pressure. If you have 4 psi restriction on return the feed side goes up 4 psi. Return should be 0 psi.

My sons 345 bored .020 over with Isky dual grind cam is running 13 PSI with plenty left over in VE table in a heavy 1210 4x4 truck with utility bed.

Biggest problem with fuel pressure other then stock is BPW must also be changed. If the 2 are not correct you will have major issues if even possible getting your VE tables correct for 128 BLMs. I'll attach an Injector Sizing Spreadsheet so you can see what I'm saying, it is set for 345 IH bore and stroke, 5.7L injectors, 13 psi, BPW is very close to stock bin.

[ninerscout]

I do need a different scale gauge. One is 0-15psi and it buries it. My other gauge is a high pressure gauge and may not be accurate because it is a small percent of the gauge. My Mac gauges have little use and only use by me. I will check for a restriction in the return further. No physical signs like pinches or kinks. I am running a rubber 5/16 hose from about 2 feet from the throttle body to the tank. No re-stricter in the tank inlet. I will tee into the return and see if I get pressure. Maybe I will run a hard line back to the tank. Thanks for all your help.

Ninerscout

[EagleMark]

Many a guy has been stung by using a vent line on a scout tank (and others) from charcoal recovery system. It looks like a good return but inside tank is a pinhole...

If there's no restriction on return and the MAC gauge is accurate the only other possibility is something is wrong in regulater. I once had an extra plastic washer in return line fitting, only supposed to have one, I had 2 and one split and blocked return flow but did not leak! That was a bugger to find!

If you have another injector pod you can plumb it in to lines without installing it on TBI and turn key on to check pressure to rule out gauge or regulater issue?