Not that I can see thus far . If you know better please share!dyeager535 said:
CK5
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OBA artificial high idle ideas?
- Thread starter southernspeed
- Start date
Looking at the pinouts last night, it didn't appear that the 747 had any of that stuff "spare", regardless of application.
I looked at some of the later TBI ECM's, even with a 4L60E, and didn't see any of it.
Here's one interesting setup, but perhaps not what you are looking for. I think it does way more than what I'll ever need. http://www.dynamicefi.com/
I looked at some of the later TBI ECM's, even with a 4L60E, and didn't see any of it.
Here's one interesting setup, but perhaps not what you are looking for. I think it does way more than what I'll ever need. http://www.dynamicefi.com/
WOW!! That's really interesting. I was wondering about fueling a 383 I fancied building and a crossfire set up would be really cool.dyeager535 said:
I get in touch with them and see if it's possible to run the std TBI set up on the 4 injector ECM until I build the 383.
It's got some interesting add-ons too. Thanks for the link.
I believe that is a product evolved from a project on thirdgen. You can probably read a lot about it over on the diy prom forum there.
FWP
CRS
Thanks guys for the ideas! Sorry to intrude on your post Mark.
Back to the original question. I was thinking about this for a bit. What happens when you step on the accelerator at idle? The voltage level to the ECM increases via the TPS input (More fuel is added via ECM- how much depending on MAP) and the butterflies mechanically open (More air is added mechanically). In general, the IAC bypasses the butterfly valves. If you could;
1. Input your own tps voltage via relay and voltage divider (easy enough)
2. Generate the needed input to the IAC to increase airflow around the valves- This one I'm not sure about. Not knowing what the IAC really is internally... Is at a true stepper motor or some other device? Anyone know?
thoughts?
Back to the original question. I was thinking about this for a bit. What happens when you step on the accelerator at idle? The voltage level to the ECM increases via the TPS input (More fuel is added via ECM- how much depending on MAP) and the butterflies mechanically open (More air is added mechanically). In general, the IAC bypasses the butterfly valves. If you could;
1. Input your own tps voltage via relay and voltage divider (easy enough)
2. Generate the needed input to the IAC to increase airflow around the valves- This one I'm not sure about. Not knowing what the IAC really is internally... Is at a true stepper motor or some other device? Anyone know?
thoughts?
It is a stepper motor and what your describing (I think) is basicaly what the ECM would do when you command A/C or PS on such equipt models.FWP said:
I think I'm going to go the EBL route at some point, so I can sort this out with that. I would've nice to do it with my '7747 but it doesn't seem possible.
therobzilla
1/2 ton status
My thoughts and experience on this subject:
I have in the past had the bike shifter, and the PTO adjustment knob, run thru my firewall to the TPI. The problem I had with this was the adjustment of the cable to allow enought travel to get the Idle to where it needs to be, and the FLEX between the motor and the body of the truck.
Let me tell you, this never happend and I'm not an idiot. When the blazer really flexed, remember first gen, and the lever was not even in use, it would engage the trottle lever on the TPI and this was UGLY on a slow going rock crawling trail... Just when you don't expect it, the idle surges up because the flex between the truck and the motor was huge. You end up using a pull chain between the cable and the TPI or carb. This was the challenge, as the amount of pull chain needs ended up binding up between the other cables, kickdown and throttle. For my setup it just did not work... I tried all ways from sunday and still could not get the adjustment to work out correctly.
Then I tried the ECM use with the fans/AC pinout on the ECM. It just as not enought to run up the throttle thru the ECM. Not enough to get the idle to a sufficent RPM to run the OBA.
I ended up going with the Offroadengineering setup, it works thru the Idle Air Control Motor. It's all elec, and is very easy to use, but it's not the total solution at least on MY TPI. They say it works great on TBI's but the use was sketchy on my TPI. Always works, but the max I can get the idle up to for OBA is around 1300 RPM. Just on the cusp on running the OBA.
It works great for just a little more throttle on the steep climbs, and even better for lowering the idle on downhill decents, but for OBA is on the cusp.
I still like it but it's a little short of my expeciation. BYW, it's not cheap, and it wears out the Idle Air Control Motors much faster than normal.
Just my opion.
Here is the link to the company I got it from:
http://www.offroadengineering.com/200_series.htm
I have in the past had the bike shifter, and the PTO adjustment knob, run thru my firewall to the TPI. The problem I had with this was the adjustment of the cable to allow enought travel to get the Idle to where it needs to be, and the FLEX between the motor and the body of the truck.
Let me tell you, this never happend and I'm not an idiot. When the blazer really flexed, remember first gen, and the lever was not even in use, it would engage the trottle lever on the TPI and this was UGLY on a slow going rock crawling trail... Just when you don't expect it, the idle surges up because the flex between the truck and the motor was huge. You end up using a pull chain between the cable and the TPI or carb. This was the challenge, as the amount of pull chain needs ended up binding up between the other cables, kickdown and throttle. For my setup it just did not work... I tried all ways from sunday and still could not get the adjustment to work out correctly.
Then I tried the ECM use with the fans/AC pinout on the ECM. It just as not enought to run up the throttle thru the ECM. Not enough to get the idle to a sufficent RPM to run the OBA.
I ended up going with the Offroadengineering setup, it works thru the Idle Air Control Motor. It's all elec, and is very easy to use, but it's not the total solution at least on MY TPI. They say it works great on TBI's but the use was sketchy on my TPI. Always works, but the max I can get the idle up to for OBA is around 1300 RPM. Just on the cusp on running the OBA.
It works great for just a little more throttle on the steep climbs, and even better for lowering the idle on downhill decents, but for OBA is on the cusp.
I still like it but it's a little short of my expeciation. BYW, it's not cheap, and it wears out the Idle Air Control Motors much faster than normal.
Just my opion.
Here is the link to the company I got it from:
http://www.offroadengineering.com/200_series.htm
Thanks, that's really interesting. I've just ordered an EBL ecu which should give me a spare pin for fans etc to use for the high idle. I'll just dial in higher revs. But that link is interesting too. I like the idea of lowering the idle at will.therobzilla said:
You say it wears out the idle air stepper? How quickly? The stepper is working all the time anyway so this gadget must work the nuts off of it.
What was your idle like when it was under the control of their unit?
