Accel Gen 7 start up and high rpm problem

[supremeefi]

Easy, set your datalog for 20 min or so, remember it registers in seconds.
Use these parameters,
RPM
TPS
MAP make sure you pick the same one as your tables, i.e. KPA, % etc.
O2 Feedback
O2 correction
Timing

Make sure you've set your rpms in the tables (F2, F3, F4) to reflect your driving. No sense in having tables that go to 6500 if you're not going to run it there, you're wasting resolution. Store your existing cal, put your Acceleration modifier at 1.0 across the graph. Enable the Datalog, drive the car making an effort to accelerate smoothly and with no excessive pedal movement. hold for a second or two at various loads and rpm's. When the datalog is done it will automaticlaly store it by dating it, i.e. 06132011 etc.
Then open your cal, press F2, go to "Overlay". Click on the datalog you just did. All the cells that you hit during your drive will be highlighted in blue. Down on the bottom it will tell you the actual O2 and correction as well as the other parameters you picked for the log. By pressing the page up or page down keys on your computor keyboard it will move the cells around the graph in the order they were stored. Correct them accordingly and send to the ECM. When you're done then address your transient fueling, the acceleration modifier, TPS ROC, and Tau. Make sure you've set your air/fuel table to the values you want where and when you want them beforehand. And obviously make sure it's up to temp, timing is good and there are no other modifiers in use.
Once you do it the first time it gets easier, you can do different parts of the map, full throttle, cruise etc all at once.
Then fine tune from there, air/fuels, spark timing etc. And remember all fueling calibrations are taken from the VE, if you change that you change other areas, that's why you do this, the "Steady State" stuff first.

When done right I'll put the drivability of the Accel up against anything, even systems that cost twice as much.

Hope this helps.
Mark

[GregWeld]

Originally Posted by supremeefi

Just an FYI for everyone, although you could say the IAC calibration can effect tip in therefore acceleration, in reality the IAC and acceleration modifier are not directly related in any way on any system, Accel or not. 2 different things.

You could do like one shop just did (I had to "just say NO") on a buddies car -- they teed the IAC into his power brake vacuum hose....


Yeah -- like that works!

Why is it that when people see EFI -- their brain goes into a sink hole?

[Jim Nilsen]

It's been a long week, the TOB is rebuilt and back in. Started the car back up and checked for leaks and all is good.

I have been talking to Mark and he is looking at my cal and datalogs if I got them to him correctly. I can't thank him enough for helping me.

Lot's of things on the checklist and it will be a long day. I have a friend coming over and we are going to change the brake fluid and get the rest of the car prepped. It's gonna be run what you brung again this year but it will be a big step up from the last time.

See ya all in Michigan !!!

[Jim Nilsen]

The Motorstate was a blast and the car made it there and back on it's own. The PS went out in the 2nd session and made it too hard to steer on the track to be able to recover from a slide, the auto cross was a lot of work but I could manuvere the coarse and finally made a really good run in spite of the engine rteaking up in the high rpm.

I am finally caught up on things at home and am getting to the problems at hand. The rebuilt rack is ready to go in and I am getting a new fuel filter next week to see if it is the part of my rpm problem.

I have 2 weeks to go and the heidt's event will already be here. Steering 1st and then back to the engine problem. I have to be able to get around without the workout and the car runs well enough to make even if i don't get it sorted out.

I am hoping for the problems to go away without a bunch of parts swapping in the ignition.

Now back to the fun of 4th of July

[camcojb]

congrats Jim, sounds like fun even with the problems.

[Jim Nilsen]

After a bunch of searching and going thru the fuel system and finding the clogged filters and then still having the miss I broke down and just got a new dual sync distributor. the Irony of it all is that I ordered the new one at 3pm and by 7pm I had a code 72 which is a cam and crank sensor pickup problem code. So the diagnoses and the timing was as spot on as it could get.

The car runs great now and the rev limiter sounds are actually the rev limiter now. The best thing is that I have finally gotten used to shifting early and I am better at getting to the shift before the r's get to far up. The IQ3 shift lghts have taken me some time to get used to, I have finally stopped looking at the tach for the time to shift. Old habits are hard to stop.

they say the weather is good for saturday and I am really looking forward to seeing how good the car runs when it is running good!!!

[camcojb]

I have had my go-rounds with those dual syncs............... Glad you got it figured out Jim.

[GregWeld]

After replacing THREE Dual Syncs --- I switched to batch fire and run a regular MSD 6 Digital box and MSD distributor.... I don't really need the sequential firing mode since I don't have to worry about emissions and or getting the very last .01 MPG out of the pigs.

NEVER once had a problem with anything EFI after that.

[supremeefi]

I hear you guys.

Just to let you all know I have just taken delivery of a newly redesigned Accel Dual Sync for a SBF. The trigger wheel has been revamped as well as the mounting for the sensors. Seems those were the major problems.

I'll let you know how it goes. It's going in a Thruster'd 362 SBF with an EFI'd RPM intake.

[TurboNova]

Originally Posted by GregWeld

After replacing THREE Dual Syncs --- I switched to batch fire and run a regular MSD 6 Digital box and MSD distributor.... I don't really need the sequential firing mode since I don't have to worry about emissions and or getting the very last .01 MPG out of the pigs.

NEVER once had a problem with anything EFI after that.

It's not just the last .01 MPG but also duty cycle of the injectors. With bank to bank mode you end up using twice as much duty cycle since the injectors fire twice as many times. The injectors all firing in the rail also make for inconsistent A/F cylinder to cylinder too, since the pulses are all banging around in the same rail.

Sequential is also worth some HP, emissions and low speed drivability. There are many ways that are better than any of the dual sync distributors out there.

My favorite way is a MSD or FAST crank trigger for RPM and a regular MSD distributor modded to be a cam sync. That will have zero problems and the crank trigger is way more accurate in the timing department. This setup will work with most stand alone ecus no matter what the brand.