Noob with a ramjet 350 cammed tbi.

**dud** · 03-05-2016

I've been reading & experimenting a bunch for a couple of months now and I think I've finally learned enough to ask a few questions that I can't seem to find answers to. Sometimes I can't see the forest for the trees. :rolleye:

Here are the specs on the truck and engine that I'm working with.

1968 Chevy truck with a complete 1993 K1500 drive train. 373 gears.
Freshened up stock 5.7 tbi block
Vortec heads
Edelbrock Performer RPM 7116 Intake with 1/2" aluminum tbi adapter.
GM Ram Jet 350 Cam with Compcams 1.5 roller tip rockers.
Stock bore TBI with Ultimate Mods done.
96 vortec truck fuel pump.
Converted stock regulator to adjustable.
FP set at about 21psi with 18lb. spring cranked up a little.
16168625 pcm with $E6 mask.

I'm using the Moates APU1 with TunerPro RT to emulate and log.

I have my VE tables pretty close I think. The truck runs fair but there's a lot more that I can do to improve driveability. This has been one heckuva steep learning curve. :yikes:

I have the static timing set at 0* with the brown wire unhooked and "Initial Spark Advance" in the bin set to 0.
I changed the "Knock Retard" setting in the bin to 020F to log knock retard instead of battery voltage. The logs aren't showing any knock retard and I can hear pinging around 2000+ rpm and 60+ kpa. Also the spark advance history table isn't showing as much advance (avg. -9+) as the Main Spark Table says I should be getting so I'm thinking spark retard may be happening but not showing up in the logs.

I'm logging plenty of knock retard counts but not showing and knock retard. Can you log knock retard counts if knock sensor is not working?
I've put in a new konck sensor.

I've set the injector flow to 77lbs/hr due to the 21psi fuel pressure. So far this is keeping the VE numbers from low 40's to low 90's.
The IDC% and injector flow in the logs don't look right I don't understand why.

Eventually I'd like to upgrade the TBI. Would I be better off with a big block tbi or a bored stock tbi. I think I'd like to stay with 5.7 injectors.

I'm attaching my xdf,xdl and adx for you guys to see if I have anything set wrong if you get a chance. Any and all help or advice is greatly appreciated.

DUD

**Raksj04** · 07-21-2016

Is there a way to use these files with a different mask $0D? I have a very similar setup.

**wanderingturtle** · 07-25-2016

I'll be following this, I'd like to know about the knock logging too.

**Kitch** · 07-25-2016

I'm guessing by now you've sorted your problem, I'm on the learning curve as well and there are people here that will know more about your combo than I do.
Not sure why you are getting so many knock counts, especially when the load isn't that high.
Most guys with Vortec head combos tend to recomend 10° base timing but with all your knock count I'd be careful trying that.
I've found with "TBI" the "Inj DC%" displays 50% or the DC% for just one injector, I normally change the formula to represent both the injectors i.e. if you were getting 50% injector DC% displayed then it was actually running at 100%, so by changing the formula it would display 100%.
The log you've attached shows a low coolant temperature (70°), did you record that log when the engine was warming up or do you run a cooler thermostat?

**Fast355** · 07-26-2016

Originally Posted by Kitch

I'm guessing by now you've sorted your problem, I'm on the learning curve as well and there are people here that will know more about your combo than I do.
Not sure why you are getting so many knock counts, especially when the load isn't that high.
Most guys with Vortec head combos tend to recomend 10° base timing but with all your knock count I'd be careful trying that.
I've found with "TBI" the "Inj DC%" displays 50% or the DC% for just one injector, I normally change the formula to represent both the injectors i.e. if you were getting 50% injector DC% displayed then it was actually running at 100%, so by changing the formula it would display 100%.
The log you've attached shows a low coolant temperature (70°), did you record that log when the engine was warming up or do you run a cooler thermostat?

Its not that it is a single injector being read, its that most duty cycle calculations forget TBI injector fire 2x per crank rotation each.

**dud** · 07-26-2016

I found the problem with my timing retard. I had to zero out "Altitude Spark Bias". This was taking 9.8* of timing off the whole table. The difference in the way the engine ran after this change was amazing. I had a lot of issues with with audible pinging that I just couldn't get rid of by taking more timing out. Didn't realise lack of timing to start with could cause the same problem. I learned this here:
http://www.gearhead-efi.com/Fuel-Inj...es-timing-Math

I bypassed the knock sensor before I found the solution to my problem and still haven't hooked it back up, so I don't know if I would still be getting a lot of knock counts or not. I figure the link-bar roller lifters I'm using might have been causing the high knock counts even though I wasn't actually logging any knock retard. From what I've read, I think knock counts without knock retard is possible maybe even normal is some situations.

I also changed the formula in the adx to reflect the proper injector firing as you illustrated. I found this a few weeks ago in a thread that Fast355 had replied to.

As for the 70*C coolant temp., that's bout as warm as I can get this thing to run. I'm running a 180* thermostat (actually tried several) and it still wants to run about 155-160*F. If I'm idleing in traffic for long periods of time in 90* weather it'll creep up to 195-200*F. Never had trouble with a 350 not warming up.

Anyhoo, got this thing running pretty good now. No pinging and I've even added a little timing in a couple of places. Still need to fine tune the AE stuff in a couple places, and there is a slight surge on occasion when decelerating and sometimes at idle. I'm still trying to get my head around the O2 settings since I think that may be where the surging problem is coming from.

Attached is my current progress if anyone is interested.

**Havens78** · 08-08-2016

Thank you Dud for posting your progress, I have this exact setup ready to go into my 93 this next weekend. It is the exact same except my gears are 3.42 and I have not purchased the newer pump. I just replaced my stock pump 5k miles ago and am not sure i'll have time to get to it during the rebuild.