New start-up help

[daveismissing]

MY recollection is that the ECM does some calibration routine on the IAC ,,,,,Maybe if this is a brand new unit the initial position is way out?. I "think" the counts are arbitrary and from the last calibration. If you can see when it calibrates as per attached then ignore me.

Dennis Leek's definitive IAC description:

https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwj5_oGq9NnXAhVj8IMKHZjbBfIQFgg2MAU&url=http%3A%2F%2Fturbobuick.com%2Fattachments%2Fidle-speed-control-pdf.179303%2F&usg=AOvVaw01jAMdUqHAYW0th-2wdbX_

[daveismissing]

here

[ULYCYC]

After reading 10 pages  I'm wondering how the car ran the day you parked it "too many years ago"
As a rule settings like translator switches, IAC, TPS, fuel pressure, Chips or its settings don't change after time.  I would start there then look for what  varnished gas contaminated, Flush out the fuel system then replace the fuel filter and clean or replace the injectors. Forget about trying to set any parameters  until the car can reach operating temps and idle anywhere around 1000rpms. Hold the throttle open with a wedge to do that and forget about iac's for now.  Also your low compression could be from the cylinders being washed down from being too rich. Change the oil and filter and dont worry about compression until you have a few hours of running time. To save some money you can clean the plugs with some carb cleaner then rinse with starting fluid also clean the O2 sensor with a propane torch a few minutes until it glows.

[V6DVette]

After reading 10 pages  I'm wondering how the car ran the day you parked it "too many years ago"
As a rule settings like translator switches, IAC, TPS, fuel pressure, Chips or its settings don't change after time.  I would start there then look for what  varnished gas contaminated, Flush out the fuel system then replace the fuel filter and clean or replace the injectors. Forget about trying to set any parameters  until the car can reach operating temps and idle anywhere around 1000rpms. Hold the throttle open with a wedge to do that and forget about iac's for now.  Also your low compression could be from the cylinders being washed down from being too rich. Change the oil and filter and dont worry about compression until you have a few hours of running time. To save some money you can clean the plugs with some carb cleaner then rinse with starting fluid also clean the O2 sensor with a propane torch a few minutes until it glows.

The donor car the engine came from was wrapped around a tree I was told. I believe that because the header was damaged on the passenger side and that side valve cover was cracked where it hit the fire wall. The kid that owned  the car just had the engine rebuilt. I pulled the intake and oil pan off and it was spotless so I believe that too. The entire fuel system is new. Foam filled Fuel cell, pump, braided SS lines, 2 filters, (strainer before the pump, filter after) Everything was rinsed and flushed before starting the engine.
 So I'm gonna pull and clean the plugs again, clean the 02 sensor and start the engine again. Get it above 1000 RPMs and let it run while I read all about the IAC Dave linked to. I may run out of gas (again) Who knew that little thing was worth 5 pages!

[Scoobum]

Steve...rememb er Dans Roadrunner with the foam filled fuel cell from this spring. Not related...but I'd be getting that crap outta there.

[Steve Wood]

I remember

[V6DVette]

Todays update= after cleaning plugs and O2- Turned on the key and toggled to IAC- it was reading 140. Started engine and it shoots up to 175. I don't understand why that would happen. Also the AF was 20! I shimmed the throttle to around 1000 RPM and let it run for 1/2hr. Fan coming on @166.(eyes tearing even with the exhaust piped outside) Some where around 150~ suddenly the engine smoothed out some. I checked the AF and it went down to 7. IAC down to 0.
 Was able to plug the vac like back in the regulator and the idle came down to about 750 -800.
I stopped while I was ahead??? (+ my bride was calling me in for dinner)

[good2win22]

You're on your way now. Good luck

[Scoobum]

If that fuel cell has foam in it...drain it and remove the foam. The link is of Dan Kellers Roadrunner he brought up from Florida last winter. It was a built race car that was stored for several years. Upon fire up the fuel pressure gauge was bouncing. Picked Steves brain here on the board as to the issue...and it ended up being the foam had deteriorated over the years and got stuck in the fuel line. I believe it was the line between the tank and filter.

https://www.youtube.com/watch?v=1BwiPoRlpxo

[V6DVette]

Well it's been awhile and over 20 gallons of gas used. No changes. Starts and runs fine after the engine has passed 150 degs. I guess I'm gonna just have to wait till I can get the car on the road to see if the puter will re-learn how to start properly. So unless you guys can come up with something I'm gonna call it good till it can be put on the road.
Got lots to do to finish her up anyway. Thanks for all your help. I'm sure I'll be back. 

[278CIKILLER]

I have never heard of cleaning the o2 sensor, when they go bad i just replace them.

[Steve Wood]

with the iac set normally, there will be about 1.5 threads of the adjustment screw tip emerging to contact the lever.  Is this where yours is?

It sounds like there is an air leak somewhere to me that is making it lean until the ecm goes closed loop and adds some fuel to it...  that is assuming the injectors are spraying correctly.  I don't remember if you changed, cleaned, or what to them before starting. 

[V6DVette]

with the iac set normally, there will be about 1.5 threads of the adjustment screw tip emerging to contact the lever.  Is this where yours is?

It sounds like there is an air leak somewhere to me that is making it lean until the ecm goes closed loop and adds some fuel to it...  that is assuming the injectors are spraying correctly.  I don't remember if you changed, cleaned, or what to them before starting.

If set the the iac @ 1.5 threads it would never start. I need to give it part throttle to start. Once started it still needs throttle to run. Upwards of 15-1900 rpms. Runs very rich!


Here's a typical run from cold start to hot
O2-847         828
AF-46           12
L8-163          63
Bat-13.5
INT-128       
BL-118
CLT-70         164
ATS-63         70
RPM-1900     900
TPS-90         44
IAC-175       00


Runs like crap cold.Sputters and stalls if I let the throttle down. Plugs foul out pretty fast. (gone threw 4 set not counting cleaning each set a few times) Once the temp is above 150ish, it's almost like a different engine. Idle smooths out. Will start with no added throttle and idles fine. Can "blip" the throttle and its crisp.
 I was running it every few days with pretty much the same results. I don't think it could be an air leak as I have checked for one (couple of times) If I pull the PCV hose off while cold, the engine runs better. Higher RPMs but better. If I crank open the throttle plate more I can't get the idle down.
Thats where I left it. Have the dash pod out right now to replace the tach so it will be awhile till I can run it again.

[reality]

Your MAF numbers are way off.

[Steve Wood]

Your MAF numbers are way off.

Bingo!  if your maf numbers are at idle, then the maf appears to be bad.  It should be 4-6 at idle...with high numbers, the computer will be flooding the engine with fuel.

It looks like it is 12 with the tps at .44 instead of 4-6