Aurora 4.0l / Izuzu 5 speed swap into 88 coupe (Page 95/102)
cptsnoopy MAY 05, 07:57 AM
Got the iac working. It appears that having the Bhi & BLo wires reversed did not fry the iac. It just kept it from working correctly.

Charlie
RCR MAY 05, 08:18 AM

quote
Originally posted by cptsnoopy:

Got the iac working. It appears that having the Bhi & BLo wires reversed did not fry the iac. It just kept it from working correctly.

Charlie



Just a coil. Nothing to really damage. Just works backwards.

Mine seems to always lose it's memory. I'd think I had the same issue as you, but when it warms up, it goes back to normal.

Bob
cptsnoopy MAY 05, 01:14 PM
Thanks for the heads up Bob! So two wires to the coil and two to sense position?

Charlie


Edit, I read up on the IAC a little more and I see that there are two coils with 2 wires each...

[This message has been edited by cptsnoopy (edited 05-05-2015).]

RCR MAY 06, 07:13 AM

quote
Originally posted by cptsnoopy:

Thanks for the heads up Bob! So two wires to the coil and two to sense position?

Charlie


Edit, I read up on the IAC a little more and I see that there are two coils with 2 wires each...




Yes, stepper motor.

Bob
cptsnoopy MAY 06, 08:23 AM
Went out for a short tuning ride last evening. Still stumbles coming off idle especially after slowing down and then getting back on the throttle. However, once the engine is making power it is nice, smooth and pulls hard.
I did full throttle tuning runs in 3rd, 4th and 5th gears to try and get numbers all over the map. I will have to fill in the rest.
So far, I am very happy with the setup and how its performing power wise.
The rest should be tunable so I will report back on that progress.

Charlie
cptsnoopy MAY 08, 08:26 AM
After reading some info on the Holley systems in use, I tried a couple of their suggestions.
One was to run both Alpha-N (tps vs rpm for idle and just off idle) and Speed Density (map vs rpm for the rest of the fuel map).
Another was to enrich the fuel map in the throttle closed area when the engine is decelerating so that reduces the amount of fuel suddenly needed when the throttle blades are opened again to accelerate.
Those two things made a very big difference compared to just trying to solve the stumble using only the acceleration enrichment values.

I sense that there is still a slight stumble if the conditions are just right but further tuning should cure that.

So far, looking pretty good. Still working on getting the custom a/c manifold finished. Then we can see if this setup can handle the AZ heat...

Charlie
cptsnoopy MAY 08, 04:46 PM
pics





Charlie
cptsnoopy MAY 08, 05:44 PM
The pics were taken after this mornings test drive. The changes helped quite a lot. Much less shifting stumble along with a good off idle start every time. As I suspected, there is a little more tuning to erase the stumble and I think I'll reduce the decel cutoff restart to less than 300rpm above idle. It jerks the car slightly when decelerating and getting close to 1000 rpm. Just little things like that to fix then I should be set. For now though it is very fun to drive & is very drivable. I just try to remember that the trans is glass, especially in 2nd gear. . However I do like the ratios, I've gone over 80mph in 3rd and it's only around 4700-5000 rpm. I've got plenty of room above that. I have not tried going faster than 90 yet but that day will come.

Charlie
Will MAY 10, 07:23 PM
I hit 105 at 7000 RPM in 3rd with the Getrag... the Isuzu 3rd is slightly shorter, but the final drive is 8% taller, so you may be able to pop the headlight doors in 3rd ;-)
cptsnoopy MAY 11, 11:24 AM

quote
Originally posted by Will:

I hit 105 at 7000 RPM in 3rd with the Getrag... the Isuzu 3rd is slightly shorter, but the final drive is 8% taller, so you may be able to pop the headlight doors in 3rd ;-)


Looking forward to finding out.
Will the headlights still pop up around 110 mph with a hood vent or has anyone verified that they will stay down longer?

Charlie