Target idle.

[EagleMark]

I'm about ready to come to CA and fix this dam thing!

Actually I don't know if I could do more then you have but glad you found a couple issues today! That would be enough to mess it up you know! Only thing left is cleaned injectors and getting min air set right.

I forgot you had large cap hei, I will post another bin with proper spark latency for that if you want? I guarentee that bin will work, even without. I just wanted to see if your bin had an issue...

[jameslleary]

Thanks Mark I appreciate any help I can get, I just want it to run right stock, so I can start to learn about tuning....I know very littlel about the nitty gritty.
Just came back in from playing in the dark,,and found out that when I rev it, base timing, esc unplugged, moves 1*...oh joy. l have decided that I am going to pull the harness out for inspection, and final cleanup. The harness is from a GMT400 truck, which is the next body style after the 73-87(to 91 for HD, Blazers, And Burbs). so it isnquite a bit longer than what is meant for my application. After seeing that thread with the 60s Suburbans, I think I might mount my esc and MAP under my dashboard. I really like the clean look.

[EagleMark]

One degree is nothing, probably timing chain or distributor slop.

Really don't think harness needs an overhaul, although I would look at spark plugs wires or EFI harness to close to distributor. If it's for asteics then that is your decision.

Bin file is very close to stock, Hiway Lean Cruise, Smoother spark table, all it needs to be accurate for your motor is spark Latency correction for large cap HEI. It's the base for ever 7747 I tune, actually it's the bin from my Suburban which has the ECM permanantly hanging on floor so I can test ECMs and chips, it's my biggest test bench!

[jameslleary]

Main reason for going through the harness, is that it is too long, and snakes around behind my dash....and I may find part of my problem. Just a clean up and confirmation that everything is right.
Your at a much higher altitude than I am, Will my using that bin cause any problems? Are you running a Cat?

[EagleMark]

2000 feet, same bin for all states, yes I have a cat on the Suburban, but I like my dog much more!

It was just a shot to see if you had an issue, your welcome to it if you wish. My Suburban runs good from sea level to 6500 feet! Don't think I've ever been higher...

[jameslleary]

Cool, I will definately try it. Thanks
I will post back here periodically, with the hopes of finding the problem, and so anybody with a similar problem will find this thread in the future

[EagleMark]

Don't be a stranger!

Your one of us now, come back and share!

[jameslleary]

Ok...did the intake gaskets. No change. Running the highway mode bin, no change at idle, still have yet to take it out on the road.
One more thing that I thought i replaced but didnt, is the MAP sensor.
MAP and Injector cleaning are going to have to wait for $$$ to come in.
I also need to pull my timing cover, and check and replace my timing chain, and I may throw a stock cam back in...or one close to it. I have heard good things about the Melling MTC-1.
If those dont work, I am thinking LS 6.0 swap, or the 87-95 GM replacement engine.

[EagleMark]

Ah dude your breaking my heart here!

Didn't you say you got 19 inches of vacuum at idle? If so and no jitters it's not a cam issue. At this point I would not talk you out of a MAP, espeacilly if it's the same one from the other motor. But I would put a Small Cap Distributor in long ago, first... speaking of which here is the same bin with spark latency values for Large cap HEI. If it works I'm gonna die....

[jameslleary]

Oh cool! I thought the bin you posted the other day had the correction. I will definately try it tomorrow. The MAP is the same one I was running with the TPI setup.
I am really baffled with this. my vacuum is usually in the 17-18 range at idle.
When I stick it in drive, itseems like it settles at 600 rpm or so, and then tanks all the way down to 525, and thats where the surging starts, clear down to 450. it even does it with the IAC unplugged while trying to set minimum idle.
And naturally, the vacuum moves with the surge.

[EagleMark]

Hmmmm... that vacuum should be fine anywhere, your sea level right?

Here's the same bin with "IAC - Desired C/L Idle Speed" increased across board to 625, stock it will go as low as 525 so maybe with your slight cam we just fixed it?

It will still idle higher when cold or in neutral.

[jameslleary]

Cool, thanks. 625 seems like a happy speed for this engine. So, another min idle air setting to 525 for this bin?
Two different schools of thought on whether or not the vehicle should be in gear during Min Idle adj...some are even saying to pull the est pigtail.

[EagleMark]

Never heard pulling EST pigtail? You mean timing disconnect wire? That would be a bad idea to try and set min air at 0 timing, then add 15 degrees? I don't think so...

Just give the bin a shot, when totally warmed up and driven then let it idle and see where the IAC counts are. 20 to 40 your done. 0 and you got to close the throttle plates, over 40 got to open them. There's the GM set procedure of crossing A and B of ALDL to drive IAC closed, discconnect IAC, start engine and set to 100 RPM below desired CL idle, reconnect IAC then the problem is you have to claer codes and you loose your BLM learn, so you don't know if you got it right till you drive a half hour?. I've found it easier to close or open 1/4 turn, turn engine off for 30 seconds, start let idle, rev engine to like 1500 for 30 seconds and check IAC counts for next minute. Way quicker.

Have you checked and or replaced the vacuum line from back of TBI to MAP? Thick vacuum line, or the stock hard line that will not collapse!

[jameslleary]

Never heard pulling EST pigtail? You mean timing disconnect wire? That would be a bad idea to try and set min air at 0 timing, then add 15 degrees? I don't think so...

Just give the bin a shot, when totally warmed up and driven then let it idle and see where the IAC counts are. 20 to 40 your done. 0 and you got to close the throttle plates, over 40 got to open them. There's the GM set procedure of crossing A and B of ALDL to drive IAC closed, discconnect IAC, start engine and set to 100 RPM below desired CL idle, reconnect IAC then the problem is you have to claer codes and you loose your BLM learn, so you don't know if you got it right till you drive a half hour?. I've found it easier to close or open 1/4 turn, turn engine off for 30 seconds, start let idle, rev engine to like 1500 for 30 seconds and check IAC counts for next minute. Way quicker.

Have you checked and or replaced the vacuum line from back of TBI to MAP? Thick vacuum line, or the stock hard line that will not collapse!

yep, I have a piece of small diameter efi fuel line on the MAP.
For the 20 years that I have been doing swaps, I have always used the ALDL a and b jumper method to set idle when in gear, like GM states in the TSB they sent out in 87-88 for bottoming out IAC valves.
I was just trying to get your thoughts on the other methods.
Burning the new ASDU you sent, hen going to give it a whirl!

[jameslleary]

Mark, did you disable the IAC? mine is staying shut, not taking commands.