SBF starting/idle issues

[Hoopty5.0]

Good morning,

I'm at the end of my abilities here, can't seem to figure out what's going on. The setup is 351w with a 76mm turbo in a foxbody running a DIYPNP. Had the car running/driving with the PNP and 302 just fine before the engine swap.

- Base timing is 10°, verified TDC.
- Car will not start without holding throttle at WOT. (which is flood clear, right?)
- I can get the car to start and run (smooth, no backfires, revs clean) with the timing locked at 10° but wont idle warm without opening throttle a couple of percent. - As soon as I switch from locked timing to "use table", it backfires, wont rev, and won't really run. It's like a jekyll and hyde.
- The IAC valve sounds like a wounded goose. I have it set to 313Hz but its ridiculously loud and would love for that to go away.
- I've attached my tune file and a log for reference.

Thanks for anything you can offer.

[Matt Cramer]

Can you data log the starting issue?

Try turning off closed loop idle and get the idle dialed in to its best in open loop before tackling closed loop.

Is the timing reading correctly with a timing light?

[Hoopty5.0]

Can you data log the starting issue?

Try turning off closed loop idle and get the idle dialed in to its best in open loop before tackling closed loop.

Is the timing reading correctly with a timing light?

I will log it tonight when I get home and turn off the closed loop. The timing light was reading correctly, but I just found out I set the mechanical base timing wrong. I never pulled the spout out when setting the base. I just set the computer to 10° and adjusted it to get it to match that with the light.

[Hoopty5.0]

I remember being told the car would not run without the spout in once MS was installed. Is this false?

[Hoopty5.0]

https://youtu.be/dzum1gLoZ6w

Changed to open loop and made all timing values in the table 10 degrees. Runs fine now, so I need to try and add in higher values and see how it likes it

[Matt Cramer]

I remember being told the car would not run without the spout in once MS was installed. Is this false?

Having the SPOUT in is the only way the MS can control timing. If the car won't run with it in, something is wrong with the settings.

[Bville99gt]

I had a somewhat similar issue with a Turbo SBF 302 on MSPNP. Car would not make any power it idle fine and drove fine, but it was not making the power it should (tested at the track, it was only traping 104mph in the 1/4). The car would die with the SPOUT out. I recheck the timing, and it was way off.

Brought piston #1 up to TDC.
Took SPOUT out, and re-stab Dizzy.
Turn on car, rotate dizzy until the car started.
Verify (with SPOUT out) with a Timing Gun, and set it at 10 BTDC.
Turn off, Plug SPOUT in.
Hook up laptop open TS with current tune.
Set Fixed Table to *20
Open Timing Wizard
Turn on car, and check timing with light.
Adjust Wizard offset via TS until I see *20 BTDC timing mark.
Set to USE TABLE, and burn tune..

I ended up with 10* offset. But that was my case.

[Hoopty5.0]

I had a somewhat similar issue with a Turbo SBF 302 on MSPNP. Car would not make any power it idle fine and drove fine, but it was not making the power it should (tested at the track, it was only traping 104mph in the 1/4). The car would die with the SPOUT out. I recheck the timing, and it was way off.

Brought piston #1 up to TDC.
Took SPOUT out, and re-stab Dizzy.
Turn on car, rotate dizzy until the car started.
Verify (with SPOUT out) with a Timing Gun, and set it at 10 BTDC.
Turn off, Plug SPOUT in.
Hook up laptop open TS with current tune.
Set Fixed Table to *20
Open Timing Wizard
Turn on car, and check timing with light.
Adjust Wizard offset via TS until I see *20 BTDC timing mark.
Set to USE TABLE, and burn tune..

I ended up with 10* offset. But that was my case.

Perfect, thank you. Will try this weekend.

[Bville99gt]

Any updates?

[Hoopty5.0]

Any updates?

Apologies for ghosting! I have accomplished a lot in the last few months. I had many issues I had to handle but it runs and drives now (that's a hugely abbreviated short story).

Just yesterday I got it all figured out I think. I was using latency wrong wasn't understanding what I should be doing with it. I got it figured out last night and now we're making some good power it feels like. I still need to work on the tune a lot as there is much work to be done, but I am finally at a point where everything operates as it should and can be fine tuned for power.

[Blown88GT]

I've been using the default settings for Ignition Options.
Your comment about latency got me to thinking.
Searched this forum for "latency" & found something interesting.
The thread may be relevant, since the OP has the following: 88 Mustang GT 331 Stroker w/ AOD, MSPNP Gen2 (MS2/Extra 3.4.2) w/ LC-2 WB
http://www.msextra.com/forums/viewtopic ... cy#p491549

turbo conversion wrote: Also is there a reason you have spark hardware latency set to 10?
stanglx2002 replied: Ignition settings are just from the base tune that was provided when I purchased the computer.
turbo conversion wrote: Under dwell type for basic trigger set this to standard dwell.
You will then need to set normal dwell and spark duration for your coil type.
Also set spark hardware latency to 0.

For TFI ignition there is a help note: set to Fixed Duty for Ford's push-start TFI
Spark hardware Latency is 10 micro-sec, not sure if 0 would make any difference.

You shouldn't have to increase Latency if your Ignition Table & settings are good.
The latest tune of yours shows a Rev Limiter---progressive spark retard setting, with a maximum of 12deg.
I think your Latency is just compensating for this.

With an intercooler (which I assume you have on the turbo), progressive spark retard is not necessary, unless MAT is getting too high.

[stanglx2002]

I've been using the default settings for Ignition Options.
Your comment about latency got me to thinking.
Searched this forum for "latency" & found something interesting.
The thread may be relevant, since the OP has the following: 88 Mustang GT 331 Stroker w/ AOD, MSPNP Gen2 (MS2/Extra 3.4.2) w/ LC-2 WB
http://www.msextra.com/forums/viewtopic ... cy#p491549

turbo conversion wrote: Also is there a reason you have spark hardware latency set to 10?
stanglx2002 replied: Ignition settings are just from the base tune that was provided when I purchased the computer.
turbo conversion wrote: Under dwell type for basic trigger set this to standard dwell.
You will then need to set normal dwell and spark duration for your coil type.
Also set spark hardware latency to 0.

For TFI ignition there is a help note: set to Fixed Duty for Ford's push-start TFI
Spark hardware Latency is 10 micro-sec, not sure if 0 would make any difference.

You shouldn't have to increase Latency if your Ignition Table & settings are good.
The latest tune of yours shows a Rev Limiter---progressive spark retard setting, with a maximum of 12deg.
I think your Latency is just compensating for this.

With an intercooler (which I assume you have on the turbo), progressive spark retard is not necessary, unless MAT is getting too high.

Turbo Conversion was able to post the manual documentation showing that the Dwell Type needs to be "Fixed Duty" with a Latency of 10. I did not change these settings, since my problem turned out to be the Map vacuum line was pinched giving a very SLOW reading.

[Hoopty5.0]

Good to know. I'm still having issues. My turbo 351 made 386/375 @ 15 psi today, haha

I can't tell if it's a bad pickup in the distributor or there is noise in the signal, but at fixed ignition (20 deg in my case) and it nosedives with rpm. By 3500 rpm, its at 10 degrees. when you let off, it goes to 0. Something is way off and it isnt the latency, although it helped.

I will look into what was mentioned above.

[Hoopty5.0]

I've been using the default settings for Ignition Options.
Your comment about latency got me to thinking.
Searched this forum for "latency" & found something interesting.
The thread may be relevant, since the OP has the following: 88 Mustang GT 331 Stroker w/ AOD, MSPNP Gen2 (MS2/Extra 3.4.2) w/ LC-2 WB
http://www.msextra.com/forums/viewtopic ... cy#p491549

turbo conversion wrote: Also is there a reason you have spark hardware latency set to 10?
stanglx2002 replied: Ignition settings are just from the base tune that was provided when I purchased the computer.
turbo conversion wrote: Under dwell type for basic trigger set this to standard dwell.
You will then need to set normal dwell and spark duration for your coil type.
Also set spark hardware latency to 0.

For TFI ignition there is a help note: set to Fixed Duty for Ford's push-start TFI
Spark hardware Latency is 10 micro-sec, not sure if 0 would make any difference.

You shouldn't have to increase Latency if your Ignition Table & settings are good.
The latest tune of yours shows a Rev Limiter---progressive spark retard setting, with a maximum of 12deg.
I think your Latency is just compensating for this.

With an intercooler (which I assume you have on the turbo), progressive spark retard is not necessary, unless MAT is getting too high.

SON OF A.... Do you think that progressive retard was affecting it?

[Blown88GT]

You're still using Fixed Timing & Progressive Retard?
It's going to 0deg because that's what you've told it to do.

[Hoopty5.0]

You're still using Fixed Timing & Progressive Retard?
It's going to 0deg because that's what you've told it to do.

Understood. I don't remember ever turning it on, but I will turn off the limiter and set the latency back to 0 for now and see how it responds

[Hoopty5.0]

Removed the rev limiter, moved latency to 10 - no change.
Added noise filter - no change.

Fixed timing @ 20deg still retards to 10 degrees by 3500 rpm.

moved latency back to 100, no change.


Is there a way to test the pick up in the distributor to make sure it's good and sending an accurate signal to the MS? Or do you think it is within the tune still?

[Blown88GT]

It's the tune, but can't account for 10deg of retard. Could be a combination of below.

Ignition Options
Fixed Advance - Use Table
Latency - 10

MAT-Based Timing Retard
Is MAT getting high enough to retard?
Shouldn't with an I/C. Mine is 0 retard.

Have you confirmed base timing is 10deg BTDC?
Pull the spout to confirm with timing light.
The use Trigger Wizard to confirm.
Trigger Wizard says Ignition Offset Angle is 7.5deg? Make it 10deg.

10 degrees by 3500 rpm with what kPa load? If 200kPa then MAT could be that high if the I/C isn't working.

Looking at your 1st post
1. Base timing is 10°, verified TDC.
Still good?
2. Car will not start without holding throttle at WOT. (which is flood clear, right?)
Yes, that's flood clear. Still won't perform Normal start? Fix this before moving on to anything else. Should do normal start with base tune; if No, then not MS.
3. I can get the car to start and run (smooth, no backfires, revs clean) with the timing locked at 10° but wont idle warm without opening throttle a couple of percent. - As soon as I switch from locked timing to "use table", it backfires, wont rev, and won't really run. It's like a jekyll and hyde.
Have to look at Startup/idle settings. You're tuning bass ackwards. Startup & idle 1st (open-loop only). Then running & driving after you kill Mr. Hyde. No closed-loop until all issues resolved.
4. The IAC valve sounds like a wounded goose. I have it set to 313Hz but its ridiculously loud and would love for that to go away.
Should be silent with engine running. Reduce to 124Hz. Turn off run before start.

On paid version of TS, you can do compare tune without altering yours.
You can also export & import certain settings, like Ignition Table.

Got my tablet out to do a compare of your startup with mine.
Many settings are different. If still having starting problems, use mine. Starts every time hot or cold.
You still have 2 squirts/engine cycle, make it 4.
Looks like Startup/idle settings need a lot of work. I spent a year on mine. If weather not cold, only get 1/day.

[slow_hemi6]

Is it a push start or a ccd tfi distributor? The new 351 would not be using the old 302 installs distributor.

[Blown88GT]

Is it a push start or a ccd tfi distributor? The new 351 would not be using the old 302 installs distributor.

That's a good point! I missed this: " Had the car running/driving with the PNP and 302 just fine before the engine swap."
He might need to use Standard Dwell instead of Fixed Duty. We both have DIYPNP's.