[grivera]

I am confused with the FiTech timing settings. The combo in my signature made 521 hp @ 5373 rpm/632 tq @ 3684 rpm foot lbs of torque on an engine dyno with a Holley HP 950 at 38 degrees.

If anyone here has experience with the timing control feature please tell me if these settings seem like a good start:

Dist Base Timing: 14 deg
Idle Advance: 24 deg

1100 45kPa: 26 deg
3000 45kPa Cruise: 42 deg
6000 45kPa: 36 deg

WOT 1100 95kPa: 18 deg
WOT 3000 95kPa: 36 deg
WOT 6000 95kPa: 36 deg

Should I change anything?

[grivera]

There has to be a FiTech guru out there somewhere...

[n2ogpsj462]

PM jlmounce. I'm doing the fitech soon and read everything on here about it. Him and another guy seemed to have the most seat time with a Pontiac

[JLMounce]

Originally Posted by grivera

I am confused with the FiTech timing settings. The combo in my signature made 521 hp @ 5373 rpm/632 tq @ 3684 rpm foot lbs of torque on an engine dyno with a Holley HP 950 at 38 degrees.

If anyone here has experience with the timing control feature please tell me if these settings seem like a good start:

Dist Base Timing: 14 deg
Idle Advance: 24 deg

1100 45kPa: 26 deg
3000 45kPa Cruise: 42 deg
6000 45kPa: 36 deg

WOT 1100 95kPa: 18 deg
WOT 3000 95kPa: 36 deg
WOT 6000 95kPa: 36 deg

Should I change anything?

Is there any reason why you're not also commanding 38 degrees now versus when you saw on the dyno? There's not hard and fast rule, but I see a lot of literature that suggestions 12 degrees of cruise advance for non-egr vehicles. If you command a total of 38 where you engine likes it, you're only adding 4 degrees of cruise advance. That'll require some experimentation to see what your car likes at cruise, but I would think you would want a bit cruise advance if possible.

You can also experiment with adding a couple degrees of timing at your final breakpoint. You're no longer constrained by weights and springs for total advance.

If you're trying to dial this puppy in as best as it's going to get with a FiTech, I'd recommend renting some chassis dyno time and doing some experimentation on what the car likes.

Your settings look good though as is and given what you know about the engine on a dyno, should be fairly safe for driving around. If you don't already have any, get some learning cycles on the computer and start making small incremental changes as you notices areas for improvement.

[grivera]

Originally Posted by JLMounce

Is there any reason why you're not also commanding 38 degrees now versus when you saw on the dyno? There's not hard and fast rule, but I see a lot of literature that suggestions 12 degrees of cruise advance for non-egr vehicles. If you command a total of 38 where you engine likes it, you're only adding 4 degrees of cruise advance. That'll require some experimentation to see what your car likes at cruise, but I would think you would want a bit cruise advance if possible.

You can also experiment with adding a couple degrees of timing at your final breakpoint. You're no longer constrained by weights and springs for total advance.

If you're trying to dial this puppy in as best as it's going to get with a FiTech, I'd recommend renting some chassis dyno time and doing some experimentation on what the car likes.

Your settings look good though as is and given what you know about the engine on a dyno, should be fairly safe for driving around. If you don't already have any, get some learning cycles on the computer and start making small incremental changes as you notices areas for improvement.

Hi Jason - I was under the impression in the car I should play it safe with the timing and sneak up on it rather than going directly to 38. Otherwise no reason.

[JLMounce]

Originally Posted by grivera

Hi Jason - I was under the impression in the car I should play it safe with the timing and sneak up on it rather than going directly to 38. Otherwise no reason.

Certainly not a bad way to go about it. But if you know the engine liked 38 on the engine dyno and you're confident that the dyno operator put it through it's paces properly, I think you'd be fine.

With that said, better safe than sorry. You're not going to miss 20-30 hp on the street in a combo with that much torque, so adding in a margin of safety may be prudent.

[Squidward]

Without having access to mine, that looks like a pretty good starting point, and similar to where I started. The only thing I would question is why you went with 26 at 1100 45kpa. That seems like a little too much when you are coming off 24 at idle from a high vacuum state to a mid vacuum state (45kpa).

I still need some tuning after I get my car plated in the next week or two, so I have some experimentation of my own to do.

I run the same base timing (14) but I run closer to 30 at idle. I drop it back to 20 or so at 1100 coming off idle and picking up load (acceleration). Your WOT settings look like a good base to play with.

[grivera]

Good points Squid! I hadn't thought about the vacuum drop off.

I haven't had a chance to run it with these new timing settings.With old settings and AFR tables, I was getting intermittent popping out of the exhaust even during a gentle throttle not exceeding 2500 rpm - I never stabbed the throttle or went WOT. This new timing table is being combined with an AFR target change. Here are my old AFR and timing settings. Could they have contributed to the popping or is that a different issue altogether?

OLD TIMING AND AFR SETTINGS

Dist Base Timing: 14 deg
Idle Advance: 24 deg

1100 45kPa: 30 deg / AFR 13.3
3000 45kPa Cruise: 43 deg / AFR 14.4
6000 45kPa: 37 deg / AFR 13

WOT 1100 95kPa: 22 deg / AFR 12.6
WOT 3000 95kPa: 37 deg /AFR 12.6
WOT 6000 95kPa: 37 deg / AFR 12.5


NEW TIMING AND AFR SETTINGS

Dist Base Timing: 14 deg / AFR 13.8
Idle Advance: 24 deg /AFR 13.8

1100 45kPa: 26 deg / AFR 13.8
3000 45kPa Cruise: 42 deg / AFR 14.1
6000 45kPa: 36 deg / AFR 12.6

WOT 1100 95kPa: 18 deg / AFR 12.4
WOT 3000 95kPa: 36 deg / AFR 12.4
WOT 6000 95kPa: 36 deg / AFR 12.4

[grivera]

Jason- any thoughts on above?

[grivera]

I went back to basics and checked the ohms on my plug wires as well as my firing order - that's when I found out I had #2 and #7 crossed at the cap!

While I felt like an idiot, I was also happy to find the issue. I ran it this morning and it runs pretty well- fast too! no more popping through the exhaust!

It stalled once while sitting at a traffic light and about 10 minutes later while coasting to a stop. Both times it started up easily but the fact that it stalled twice is concerning.I have about 10 gallons of fuel in the tank, fwiw. Any idea where I should look to address?

[Squidward]

What is your idle rpm setting? Have you adjusted iac steps/TPS? If you don't have the TPS zero'd and the iac steps set up, you might not be getting enough air at idle. With the TPS reading zero, the iac steps should be around 10-20.

[JLMounce]

First thing I would do is check for vacuum leaks. If it's stalling on decel to idle there's a possibility you're getting unmetered air in the system.

You should also do a datalog to see what your map is looking like when the stall occurs. You may need to adjust the DFCO settings a bit. If your manifold air pressure is low enough near idle as the engine is decelerating you may trigger that DFCO (or it may be active too long) and you stall because there's no fuel to the system. Typically this is more prevalent in manual equipped cars, but if you've got a loose converter and you're slamming on the brakes, it can happen with auto equipped cars as well.

The cure is to lower the MAP threshhold for when DFCO is turned on. I can't stress enough not to turn that off completely though. That's a good way to blow up your mufflers.

[grivera]

Originally Posted by Squidward

What is your idle rpm setting? Have you adjusted iac steps/TPS? If you don't have the TPS zero'd and the iac steps set up, you might not be getting enough air at idle. With the TPS reading zero, the iac steps should be around 10-20.

My idle is set at 875. My IAC steps are typically at 5 during idle. I haven't checked them in gear. I believe my TPS is zeroo'd but I will check next time I run it.

Originally Posted by JLMounce

First thing I would do is check for vacuum leaks. If it's stalling on decel to idle there's a possibility you're getting unmetered air in the system.

You should also do a datalog to see what your map is looking like when the stall occurs. You may need to adjust the DFCO settings a bit. If your manifold air pressure is low enough near idle as the engine is decelerating you may trigger that DFCO (or it may be active too long) and you stall because there's no fuel to the system. Typically this is more prevalent in manual equipped cars, but if you've got a loose converter and you're slamming on the brakes, it can happen with auto equipped cars as well.

The cure is to lower the MAP threshhold for when DFCO is turned on. I can't stress enough not to turn that off completely though. That's a good way to blow up your mufflers.

I certainly hope I don't have a vacuum leak! I will research how to run the data logging too. I'm not familiar with the DFCO?

I called FiTech after I posted this. The tech advised that if I had fault code P0000 (which I did)- failed to mention it in thread, it may be a grounding issue- I have a cable from the base of TB to the (-) battery post. I checked from TB to battery post and as expected, the reading is zero. He also said that since I have a in-tank pump, I gotta make sure the PWM is set at 100 percent.

This all means I have a bit of work to do...

[Squidward]

Originally Posted by grivera

He also said that since I have a in-tank pump, I gotta make sure the PWM is set at 100 percent.

THAT I don't really get. My FCC says to do about 44 on the PWM at idle. I get it, fuel demand is low, so no need to run the pump ballzout because it will only recirc it back to the tank anyways. So let's say your in-tank pump is Walbro xxx lph. The FCC pump is brand y pump at 340 lph. Why can't the in-tank pump do PWM? Both supply systems plumb excess fuel back to the tank via a return line. Using the pwm just makes the pump operate dynamically based on demand, and reduces run time, which equals longer life. I thought these dc pump motors were stupid. I wonder if your in-tank pump manufacturer made their pump with PWM capability?

I would do what FiTech says for now while you get your other variables ironed out, but if it was me, I'd check with pump maker to see if it was designed to work with PWM, and then try it anyways.

[grivera]

I’ll check- it’s a Walbro 255 Lph pump

[Squidward]

I just did some searching.
http://walbrofuelpumps.com/walbro-fu...itech-efi.html

Scroll down through the description, and it says do NOT use pwm, and always use a return.

[grivera]

Thanks - I haven't had a chance to look at the settings. Mine is an in-tank Walboro pump. I have 1/2" supply and return.