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Edelbrock Proflo 4

mrk5 said:
Took the C10 to town for groceries and some efi testing. Throttle response off the line is awesome. Gonna have to relearn my pedal pressure for driving this truck. My wife was exclaiming that I was driving it like a raceway! Haha.

I have 2 issues to resolve.
  1. It was 14° this morning. Probably about 40° when we took it for a drive. It started and idled fine, but died as soon as I put it in gear. I remembered @6872xtc had to mess with cold enrichment. I'm thinking this is probably my issue too. What did you end up at for the cold enrichment @6872xtc?
  2. I have a whistle thru the throttle body at 30% throttle position and goes away within 3% either side of 30%. The Sniper did something similar that I solved with a 4-hole 1/4" thick carb to intake gasket. Curious if anyone else has experienced this. I did try without the air cleaner and that made no difference. I'm wondering if it's the secondary throttle blades opening. Anyone know if they open at 30% throttle?
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About the dieing in gear, that might go away as it learns, however, what is your IAC set at when the engine is warm, and the truck is idling in neutral? You want that low when the engine is warm in neutral (5%-7%), so it has more room to open to keep it running during load changes at idle. You may have to recalibrate the TPS if you change the idle screw on the throttle body.
 
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@folkenheath it has been a month or more since I played with my throttle stop setting, but I haven't remember seeing a process for resetting the TPS on this system. It is such a small amount of movement to change the IAC % , I have never found it to be reading on the throttle percentage. I have tried 5 to 10% on the IAC and it still does everything fine when warm, but dies if I don't catch it with the pedal, on the first movement of the truck, when too cold. And I have watched the IAC % be up around 70% during cold warm up.
 
6872xtc said:
@folkenheath it has been a month or more since I played with my throttle stop setting, but I haven't remember seeing a process for resetting the TPS on this system. It is such a small amount of movement to change the IAC % , I have never found it to be reading on the throttle percentage. I have tried 5 to 10% on the IAC and it still does everything fine when warm, but dies if I don't catch it with the pedal, on the first movement of the truck, when too cold. And I have watched the IAC % be up around 70% during cold warm up.
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From some reading in the Edelbrock documentation, the IAC does an idle reset to zero % after a complete shutdown(main relay clicks off), then key on triggers an "autozero" for the TPS. So make the driver isn't putting their foot on the throttle when they key it on. As long as the TPS shows 0% when you are off the throttle you should be good. The 100% value shouldn't change from the first time it's set in the setup wizard.
 
@mrk5

I know you have this infatuation with the 600 RPM target idle

Something to consider. Most all GM EFI units target idle to appx 800 RPM (re: TBI)
It is also where I set mine, with only a minor adjustment on cold enrichment
 
The idle target is easy to set when warmed above 165*. Anything from 500 on up to 2K I believe. There's even an idle tune technique in the manual to help trim the idle fuel.
Mine vibrates something in the dash sheetmetal if I go under 625.
 
i admit when people ask about the bluetooth instant updates on the pro flo 4 system all i have to do is bump the idle from were i have it to 500 rpm and up to 1k rpm and they wants the tablet or phone and just get blown away how easy changes can be made .

i should bump it up a bit more tho like bent77 has his .
 
mrk5 said:
Took the C10 to town for groceries and some efi testing. Throttle response off the line is awesome. Gonna have to relearn my pedal pressure for driving this truck. My wife was exclaiming that I was driving it like a raceway! Haha.

I have 2 issues to resolve.
  1. It was 14° this morning. Probably about 40° when we took it for a drive. It started and idled fine, but died as soon as I put it in gear. I remembered @6872xtc had to mess with cold enrichment. I'm thinking this is probably my issue too. What did you end up at for the cold enrichment @6872xtc?
  2. I have a whistle thru the throttle body at 30% throttle position and goes away within 3% either side of 30%. The Sniper did something similar that I solved with a 4-hole 1/4" thick carb to intake gasket. Curious if anyone else has experienced this. I did try without the air cleaner and that made no difference. I'm wondering if it's the secondary throttle blades opening. Anyone know if they open at 30% throttle?
Click to expand...


I have the same two issues.
If I let it warm up enough that the coolant temp is above 100F it doesn't die when putting it in gear. I figure I'll let it learn for a while and see if it resolves itself. If not I'll play with the idle rpm settings.
I have the same whistle! I didn't pay attention to what throttle % until I read your post. Mine is at roughly the same, right around 30%-35% throttle. I'll have to look and see if the secondaries start to open at 30% throttle. (another thought is we both have the volcano . . . . I wonder if that changes the velocity enough to cause the whistle?)

One other issue I have had is with the O2 sensor. On the 4th startup it read at 22.8AFR no matter what rpm or throttle. Next startup it read at 10.0AFR all the time. So I took it out cleaned it thoroughly with brake cleaner and it worked fine on my next run. Then it would either stick at 22.8 or 10.0, so I cleaned it again and it helped for one run. The last time it got stuck I was going to replace it, but it has been working fine as long as I don't start the engine until after I wait until the AFR move from 10.0
 
Bent77 said:
@mrk5

I know you have this infatuation with the 600 RPM target idle

Something to consider. Most all GM EFI units target idle to appx 800 RPM (re: TBI)
It is also where I set mine, with only a minor adjustment on cold enrichment
Click to expand...
All the factory efi trucks I drive idle at 500 RPM in gear. They do idle higher in park; I've never actually paid attention to it but 800 or 750 probably is right. What is different with the aftermarket efi trucks I've driven is they will maintain the same idle whether in park or gear.

Yesterday I not only had the dying when going into gear when cold, but it started doing it all the time. So I tried setting the idle at 750 and 800 RPM, but that didn't help. I gave up and went back to my desk and did some reading on the PF4 forums, but didn't really find a solution. I decided that often when I have problems like this, the solution ends up being the opposite of what I think it should be.

So contrary to @Bent77 opinion, I set the idle target at 500 RPM. I set the idle speed screw so that IAC was just within spec, 5-6%. It stopped stalling when I put it in gear. This morning it wouldn't start and stay running, which had happened the previous morning. I did get it to run by holding the throttle a little when cranking. Then it would idle just fine. And when I put it in gear, it didn't die. So setting the idle at 500 RPM seems to have helped my dying when going into gear issue.
 
MT Bill said:
I have the same two issues.
If I let it warm up enough that the coolant temp is above 100F it doesn't die when putting it in gear. I figure I'll let it learn for a while and see if it resolves itself. If not I'll play with the idle rpm settings.
I have the same whistle! I didn't pay attention to what throttle % until I read your post. Mine is at roughly the same, right around 30%-35% throttle. I'll have to look and see if the secondaries start to open at 30% throttle. (another thought is we both have the volcano . . . . I wonder if that changes the velocity enough to cause the whistle?)

One other issue I have had is with the O2 sensor. On the 4th startup it read at 22.8AFR no matter what rpm or throttle. Next startup it read at 10.0AFR all the time. So I took it out cleaned it thoroughly with brake cleaner and it worked fine on my next run. Then it would either stick at 22.8 or 10.0, so I cleaned it again and it helped for one run. The last time it got stuck I was going to replace it, but it has been working fine as long as I don't start the engine until after I wait until the AFR move from 10.0
Click to expand...
You can see my post above. The stalling when putting it in gear had gotten worse for me because it started doing it all the time even when coolant temp was at 180.

I did wonder some about the Volcano, but I wouldn't think that would happen with it being as smooth taper. Who knows, maybe it's doing weird things to the flow. I wonder if there's a chance @folkenheath put a different throttle body gasket on? If it's cut differently maybe that could be the issue.
 
I now have a developed a new problem. Last night driving home, cruising at steady state at 65mph, the engine died. I dropped it in neutral, it started back up, and I continued driving home. I figured it was just a learning glitch.

Unfortunately it happened several times on the drive to work this morning. I was able to video the digital gauge screen one of the times it happened. You will see when it dies because the actual AFR will go red because the engine isn't running.


I don't see anything that gives any indication of why it cuts off. And this happened with the coolant temp up to 180. I couldn't seem to find a speed correlation either. I know I had instances of it dying at around 35mph (in the video above), 45mph, and 65mph. I think most times it happened under steady state, but I know at least once it happened during light acceleration.

I was always able to put the engine in neutral and it fired right up. I just couldn't find anything that would make it happen. Just seems to be random.

Here's another video of driving. I was hoping to catch a stall, but didn't. You'll see at the end of the video I was starting to become a traffic hazard.


When it happened the 1 time last night, I thought it might learn it away. After the drive in this morning, I'm not so sure. Plus it's a little stressful driving when you don't know if/when it might die.
 
Looks like your fuel pressure drops to 30 just before you stall. Could be just after too, hard to tell....
 
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skunked said:
Looks like your fuel pressure drops to 30 just before you stall. Could be just after too, hard to tell....
Click to expand...
That's something I can keep an eye on. I wasn't sure if it happened right before or just after it dies.

Kain said:
your pressure reading from map sensor goes nutz just before it stalls
Click to expand...
I notice the throttle position jumps from 5 to 15 at the same time. I don't know or remember if I was accelerating at the time.

In looking on the Edelbrock forums I learned you can get an app that records the screen. I will have get that installed so it's easier to watch. I figure I may need to do some more driving to see if I can start noticing a pattern.
 
it does jump ,wonder if there connected .
when i talked to the tech at eddy he mentioned the map being bad can play with the o2 readings
 
Kain said:
it does jump ,wonder if there connected .
when i talked to the tech at eddy he mentioned the map being bad can play with the o2 readings
Click to expand...
I was debating if I should start over with the setup wizard to see if it needs reloaded.
 
I have used an Android app called "ScreenCam" that does that pretty well, you can even add the audio from the phone mic if you want.

From the looks I wonder if you are losing spark temporarily?

Also, I put the same gasket back in in the exact same orientation Edelbrock installed it (you can see the imprint from the throttle body).

About this whistle, did you guys install a turbo and not tell anyone? :pimp:

Seriously though, does it actually whistle or is it more like a tiny air leak sound from the throttle body? Can you duplicate the whistle at 30% throttle in neutral, or is it only under load? If so can you temporarily place something over the IAC inlet hole to plug it and see if it goes away?

If you can duplicate it in neutral it would be very helpful as you could try to find it then.

I've never heard any type of actual "whistle" in any of my testing the last few years, so I am curious to find out where it is coming from. I am guessing the throttle plates or IAC valve.

Make sure your intake manifold bolts and throttle body nuts are snug. I always check the manifold bolts each time it cools off the first few heat cycles.
 
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Fuel pressure could play a big role if you are seeing inconsistent numbers. What version are you on?

Also, what fuel pump are you running and how is the fuel line and fuel return ran? I assume your fuel pressure is at 43psi with the vacuum line off and plugged.
 
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