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Edelbrock Proflo 4

I had a conversation w/ a GM engineer one time many years ago. His recommendation was to get the car started, give it long enough to get the oil pressure up and flowing. And then go. Keep the throttle easy, but letting a vehicle warm up in the driveway was harder on them than driving them easy while cold. The fuel enrichment just helps wash the cylinders down, so getting it up to temp as quickly as possible was good - and driving easy would do it faster than idling.
 
That is what I'd prefer to do, but that doesn't seem to be the case. I can leave before it warms up, but then I have to 2-foot it to shift into gear without it dying. I think a big part of the issue is it being so damn cold. I'm curious how it would be if it was summer time.

I would also say relative to the other vehicles I drive, including the Sniper on the crew cab, the cold idle RPM targets on the PF4 are much lower than I feel like they should be. I wish that was adjustable. I've been tempted to change the base target idle for the initial start of the drive just to see if that would work. Then idle it down after it's driven for a little while.

The cold idle on the PF4 seems to be some value added to the base target idle. I think it adds about 300 RPM for the coldest condition. So if I cheated the target idle up to 800 RPM, I would get an 1100RPM cold idle.
 
mrk5 said:
I'm hoping that because I bought that Bosch O2 sensor after driving the one from the kit without it plugged in, I won't have the failing O2 sensor issue.

I've still been having the issue with it dying when the engine is cold and I put it in gear. I have figured out if I let it warm up to 110°F coolant temp, then I can put it in gear and it drives fine. Although this morning it was -1°F and I warmed the engine up to 110° and it almost died when I put it in gear, but it did catch itself and keep running.

I have decided I'm going to call the tech line to ask about it after the holidays. Another thing I've observed is when it's warming up in the morning it runs below the target AFR. The target is 13.5 and it runs 12.5 but increases as the coolant warms up. Actually the reason I chose 110° for when to try putting it in gear is because that's when the AFR is at about 13.1 by that point. I do know the Sniper lowers the AFR target at the colder temperatures, but the reason I know that is because the target AFR reflects it. The PF4 shows the target AFR to be the idle set point set in the advance tuning. So it makes me curious if it's supposed to be running a richer AFR and the target AFR just doesn't reflect it.

The other thing minor issue is the IAC likes to do its own thing sometimes. I'll be stopped at a light and all of a sudden the IAC will start opening up, as high as 60% at times. Nothing else is reading outside of what it should be, just the IAC deciding to idle the engine higher for some reason. I keep thinking it's some glitch that will disappear with more learning. It doesn't happen with regular frequency just from time to time. About them time I think maybe it's done happening, it does it again.
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I forgot to add the kicker to the rich AFR value on initial startup. Even tho it's running rich by the AFR reading, the SFT is adding fuel.
 
Something interesting I noticed today. The app was showing voltage at 11.5 to 12.5 Volts intermittently. I could tell if there was a circumstance that caused it to happen; RPM didn't seem to matter, but I thought maybe fans were doing it. Since I have the fans run off the Derale PWM controller, I don't really know when they are on at full force or just partial. But other times the voltage would read 13.2 to 13.5 volts.

The interesting thing is I have 2 USB power plugs; one in the cigarette lighter socket and the other is wired to the fuse block. Both of the USB adapters have battery voltage and they were both reading steady 13.7 volts the entire time.

I read on the PF4 forums that it's not uncommon for the app voltage reading to different from actual battery voltage. Some people have solved this with additional grounds or running a charge wire directly from the altnernator to the battery; which I have the latter. The only ground I haven't upgraded is from the battery to the frame. Curious if that would change anything.

Anyway, I wanted to share what I found in case others see something similar. It's not unusual and you don't need to worry much about it if you know the battery voltage is good.
 
Still been fighting the poor cold start and truck dying when shifted in gear. I've been trying a lot of settings, mostly raising/lowering cold enrichment and target idle RPM. I was having some luck with the idle RPM set with it in gear, but I was still having issues at lower temperatures. Messing the cold enrichment helped shifting into gear but then seemed to make the cold starting worse.

The current settings look to be showing the most promise. I have target idle set to 700 RPM with IAC at 5% in Park. This was the highest RPM the truck can idle without feeling like it's trying to take off at a stop light. I had been playing with trying to run more idle spark timing - as high as 30°. Now I have it backed down to 24°. I did this because I remembered with the carb, the engine didn't like having the timing advanced above 12° plus the 10° of vacuum advance. I was also playing with the idle AFR trying to lean it out to see if I could improve fuel mileage. I was just a slight hesitation accelerating from a stop, so I ended up at 13.3 which seemed to be the leanest idle AFR I could get without acceleration issues. Pretty much all the idle AFR's I tried resulted in the same vacuum readings, but I felt like 13.3 seemed to maybe be just a tiny bit better.

The last few times I've started the truck driving with a cold engine, I have not had trouble with it dying when shifting into gear. So far that's the best result because before the best I've done is occasional stalling.

It's also starting better. I'm still dialing in the crank fuel in the advanced tab with the different temperature ranges.
 
have you messed with crank fuel?when cold? or does cold enrichment do that too?
 
Kain said:
have you messed with crank fuel?when cold? or does cold enrichment do that too?
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I am messing with crank fuel now.

As I understand it, the cold enrichment does more for the engine running at the colder temperatures, but it must also affect the starting. I could bump that up and have better luck with the truck not dying when I shifted into gear, but then it was making it really hard to start. I would have to rev the motor and it was blowing what I assumed to be unburnt fuel out the exhaust. On one hand I was adding cold enrichment, but subtracting crank fuel. It seemed to be helping with the shifting into gear, but starting was getting really bad.

That's when I decided to try and see if I could get other parameters set to where I wasn't having to use the cold enrichment to keep the truck running when shifting into gear. It just seemed like I was going in circles trying to use it.

@Bent77 kept banging on me to up my idle RPM. In my searching thru old threads on the PF4 forum it seemed like many times the tech people would tell others to up their idle RPM. I'd been trying to get mine to run at 600. I noticed during the engine warm up when the system keeps the idle RPM higher that when idle was at 700 it wasn't as annoying at the stop lights. So when I still wasn't having success with the cold enrichment, I decided to try setting the target idle at the highest RPM I could tolerate which seems to be 700. I think this might be helping my problem. And then getting the balance right between that and idle AFR and timing.
 
mrk5 said:
Still been fighting the poor cold start and truck dying when shifted in gear. I've been trying a lot of settings, mostly raising/lowering cold enrichment and target idle RPM. I was having some luck with the idle RPM set with it in gear, but I was still having issues at lower temperatures. Messing the cold enrichment helped shifting into gear but then seemed to make the cold starting worse.

The current settings look to be showing the most promise. I have target idle set to 700 RPM with IAC at 5% in Park. This was the highest RPM the truck can idle without feeling like it's trying to take off at a stop light. I had been playing with trying to run more idle spark timing - as high as 30°. Now I have it backed down to 24°. I did this because I remembered with the carb, the engine didn't like having the timing advanced above 12° plus the 10° of vacuum advance. I was also playing with the idle AFR trying to lean it out to see if I could improve fuel mileage. I was just a slight hesitation accelerating from a stop, so I ended up at 13.3 which seemed to be the leanest idle AFR I could get without acceleration issues. Pretty much all the idle AFR's I tried resulted in the same vacuum readings, but I felt like 13.3 seemed to maybe be just a tiny bit better.

The last few times I've started the truck driving with a cold engine, I have not had trouble with it dying when shifting into gear. So far that's the best result because before the best I've done is occasional stalling.

It's also starting better. I'm still dialing in the crank fuel in the advanced tab with the different temperature ranges.
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I'm glad you posted this! I've been fighting the same issues. I haven't tried playing with the AFR targets yet, I left those as recommended by the edelbrock tech I spoke to.
But I have been playing with idle targets and screw settings in park, and in gear, to get it to shift into gear without dying . . . . still no solution as of yet. It seems to be better the lower I go with the idle settings, but still dies every time I put it in gear and the coolant temp is below 165F.
 
MT Bill said:
I'm glad you posted this! I've been fighting the same issues. I haven't tried playing with the AFR targets yet, I left those as recommended by the edelbrock tech I spoke to.
But I have been playing with idle targets and screw settings in park, and in gear, to get it to shift into gear without dying . . . . still no solution as of yet. It seems to be better the lower I go with the idle settings, but still dies every time I put it in gear and the coolant temp is below 165F.
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You might try going to the higher target RPM. I had been trying to make it work at lower RPM and just couldn't get it consistent. I think that and setting it to idle a little richer with the lower AFR and timing is helping. When I shift it into gear cold now, the idle doesn't seem to fall quite as much.
 
I would think that cold enrichment would be in effect when it's below a temperature threshold - usually somewhere around the thermostat temp. Such as warm-up conditions.

Have you talked to Edelbrock about this?
 
JoshHefnerX said:
I would think that cold enrichment would be in effect when it's below a temperature threshold - usually somewhere around the thermostat temp. Such as warm-up conditions.

Have you talked to Edelbrock about this?
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There is enrichment that occurs as it warms up. It thru me off at first because it shows the actual AFR being lower/richer until it reaches 165°, then it reaches runs at the target AFR. I had to ask about it because I could figure out why the actual AFR wasn't matching the target at the lower temps.

In addition to that, there is an advance tuning feature that allow you to add additional fueling when the engine is cold.

I have had some discussion with the Edelbrock tech people on their forum, but they haven't had any specific recommendations. That's what's led me to the most recent changes.
 
Have any of you guys adjusted the cold enrichment in the temperature range steps? Or just the global adjustment?
I went into the advanced setting for it, then also made sure that the global didn't change unless I wanted it to.
I had mine change the global when it had the old software once.
I honestly don't think that the AFR when warming up is a great concern, just how does it run. But that's my opinion.
I haven't tried any adjustments for a long time, but mine seems to be good after warming up some.
 
6872xtc said:
Have any of you guys adjusted the cold enrichment in the temperature range steps? Or just the global adjustment?
I went into the advanced setting for it, then also made sure that the global didn't change unless I wanted it to.
I had mine change the global when it had the old software once.
I honestly don't think that the AFR when warming up is a great concern, just how does it run. But that's my opinion.
I haven't tried any adjustments for a long time, but mine seems to be good after warming up some.
Click to expand...

I have adjusted the cold enrichment I don't have the numbers in front of me, but if I remember correctly I staggered them up to 0% at 165F.
I haven't adjusted them much after my initial setup in the first few drives, so that may be something I should look again.
 
MT Bill said:
I have adjusted the cold enrichment I don't have the numbers in front of me, but if I remember correctly I staggered them up to 0% at 165F.
I haven't adjusted them much after my initial setup in the first few drives, so that may be something I should look again.
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How much did you add?

And have you driven it several hundred miles? It may have trimmed more than you added, you would want to check your fuel trim to see how things are going.
 
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