Starting procedure

[themechanicalford]

Hey guys, question about cold start RPM’s with a non working high idle solenoid.

When I start the truck in cold temps (35 or below) I usually plug it in for about 2 hours beforehand, cycle the glow plugs 2x, put the pedal to the floor and she fires right up. Now in the summer I let my foot off the fuel pedal the moment I hear it start so the RPM’s are never more than 1000 for more than a second and then I let it idle normally until driving.

Attempting to do this recently (not because of the temps I don’t believe) causes the truck to stall as soon as I take my foot off the pedal and then I cannot get it started again and I effing hate to do it - without a small shot of ether.

If I only lift my foot off the throttle a little bit (initial starting RPM is maybe 1100-1200 and then I feather it down to 1000 RPM and I hold it there for maybe 30 seconds and then I can let it idle normally at lower RPM’s

My question. What would the high idle solenoid, if working, hold the RPM’s at. Is my starting procedure normal or ideal, or is it putting undue wear and tear on a cold motor?

I also notice that after that stall that sometimes happens I can hear what sounds like a gurgling for a second. May be coming from the fuel tank? Does this indicate an air leak or is this something that I might hear even if everything was working well from fuel moving around somewhere?

 

[Big Bart]

Yes running a cold engine up high right at start is not ideal for the engine. Also ether can be tough on a diesel.

Some things to check.

a) There is a sensor on the front of the engine that allows 12v+ power to the timing advance soleniod on the IP and the idle solenoid nearby it Till the engine gets to around 120*. The timing advance will cause your truck to clatter loudly upon start and settle down over the next 60 seconds.(If your timing is set right.) The idle advance works by you pressing the gas pedal down say 50% to let the solenoid extend, letting off the gas pedal, and it holds the throttle further off idle. It is adjustable with small wrench’s, from what I have seen the idea is for it to add +100 rpm more or ~750rpm with a cold engine running. Keep in mind if you have an automatic you do not want your truck at 1,000rpm for the first 10 minutes of driving around. It will want to move the truck and cause extra wear and tear on the tranny and brakes. But honestly if your truck is running correctly you should not need more than even 800rpm to keep it alive in +10* F. So check for power at each solenoid. Then confirm they work. Then set your idle at 650 warm and 750 cold. Also check your IP timing!
b) If your truck starts only with the pedal depressed and then stalls if released that sounds like air intrusion. So start looking for diesel leaks and think about doing your return lines. Also make sure you have anti gel in your diesel to prevent gelling of the diesel. But sounds like it’s using the fuel in the IP and what’s left in the fuel filter then stalls out till you crank or the ether runs it long enough for the lift pump to replenish the system. This is a super common problem that is worse if your glow plugs are not 100%, you IP timing is off, or your batteries or starter are weak.
c) Glow plugs are a big deal on these engines. If your wait to start light is not staying on for least 10 seconds you should do some testing. Also just because the light is on does not mean all the glow plugs work. You could have 3 dead ones even on the newer style 7.3 controller and it will still work. But if you can start the engine, then you cannot 30 seconds later, that is not a glow plug issue. I bring this up because it will be easier to start with 8 working glow plugs. It’s easy to test for bad ones and easy to replace them.

 

[themechanicalford]

Yes running a cold engine up high right at start is not ideal for the engine. Also ether can be tough on a diesel.

Some things to check.

a) There is a sensor on the front of the engine that allows 12v+ power to the timing advance soleniod on the IP and the idle solenoid nearby it Till the engine gets to around 120*. The timing advance will cause your truck to clatter loudly upon start and settle down over the next 60 seconds.(If your timing is set right.) The idle advance works by you pressing the gas pedal down say 50% to let the solenoid extend, letting off the gas pedal, and it holds the throttle further off idle. It is adjustable with a small wrench’s, from what I have seen the idea is for it to add +100 rpm more or ~750rpm with a cold engine running. Keep in mind if you have an automatic you do not want your truck at 1,000rpm for the first 10 minutes of driving around. It will want to move the truck and cause extra wear and tear on the tranny and brakes. But honestly if your truck is running correctly you should not need more than even 800rpm to keep it alive in +10* F. So check for power at each solenoid. Then confirm they work. Then set your idle at 650 warm and 750 cold. Also check your IP timing!
b) If your truck starts only with the pedal depressed and then stalls if released that sounds like air intrusion. So start looking for diesel leaks and think about doing your return lines. Also make sure you have anti gel in your diesel to prevent gelling of the diesel. But sounds like it’s using the fuel in the IP and what’s left in the fuel filter then stalls out till you crank or the ether runs it long enough for the lift pump to replenish the system. This is a super common problem that is worse if your glow plugs are not 100%, you IP timing is off, or your batteries or starter are weak.
c) Glow plugs are a big deal on these engines. If your wait to start light is not staying on for least 10 seconds you should do some testing. Also just because the light is on does not mean all the glow plugs work. You could have 3 dead ones even on the newer style 7.3 controller and it will still work. But if you can start the engine, then you cannot 30 seconds later, that is not a glow plug issue. I bring this up because it will be easier to start with 8 working glow plugs. It’s easy to test for bad ones and easy to replace them.

Hey man I really appreciate the well thought out reply. I actuallly went to order glow plugs the other day and know that I need the motorcraft brand, but it looked like they were less than $10 on Rockauto and figured I must have had the wrong part, no?

I will search the inter webs for a good tutorial on checking the idle advance (I assume that is what is referred to as the high idle solenoid?). If you can think of any YouTube channels or good tutorials for checking it that would be great, if not I’ll start digging.

Have you ever heard this gurgle that I’m talking about? It sounded like air intrusion to me but it could also be something normal I suppose.

Fuel line o-rings were replaced about 7k miles ago, the previous owner took it to a shop. Don’t believe they replaced any lines though.

 

[Cubey]

If you're curious to hear how my RV sounded this morning after sitting for 3 days, today's early morning's temps getting down around 28-30*F, and the factory block heater plugged in for about 2 hours, here's a (crappy low quality dashcam) video. That was the first start attempt under those conditions:

xc_hide_links_from_guests_guests_error_hide_media

Ignore the 2013 date, the dash cam's built in battery for the clock is bad (removed, actually) and I'm too lazy to keep up with setting it every time it loses 12V power (ie unplugged)

It was probably about 35-40*F out when I cranked it up, but I didn't think to check. I have an electric fuel pump (Holley Red) and the cold idle advance works, for what they are worth for aiding starting. I have a matched pair of 3 year old Walmart EverStart Maxx 65N batteries, so they aren't exactly fresh. I didn't put a charger on them to try to help them at all, and the starter motor very well could be the original one from the factory in 1985. I didn't press the throttle down when cranking, but I did hold it down when I turned the key to "on" to fire the glow plugs so the cold idle advance could kick on, but then let go.

Aside from the unknown 2 second knock (I have a thread I posted asking about that) it cranked up fast and idled smoothly.

 

[themechanicalford]

If you're curious to hear how my RV sounded this morning after sitting for 3 days, today's early morning's temps getting down around 28-30*F, and the factory block heater plugged in for about 2 hours, here's a (crappy low quality dashcam) video. That was the first start attempt under those conditions:

xc_hide_links_from_guests_guests_error_hide_media

Ignore the 2013 date, the dash cam's built in battery for the clock is bad (removed, actually) and I'm too lazy to keep up with setting it every time it loses 12V power (ie unplugged)

It was probably about 35-40*F out when I cranked it up, but I didn't think to check. I have an electric fuel pump (Holley Red) and the cold idle advance works, for what they are worth for aiding starting. I have a matched pair of 3 year old Walmart EverStart Maxx 65N batteries, so they aren't exactly fresh. I didn't put a charger on them to try to help them at all, and the starter motor very well could be the original one from the factory in 1985. I didn't press the throttle down when cranking, but I did hold it down when I turned the key to "on" to fire the glow plugs so the cold idle advance could kick on, but then let go.

Aside from the unknown 2 second knock (I have a thread I posted asking about that) it cranked up fast and idled smoothly.

Wow, started like new. I’m going to have to look more into fixing my cold idle advance.

 

[Cubey]

Wow, started like new. I’m going to have to look more into fixing my cold idle advance.

I broke the temp senor for cold idle advance on my NA F250 years ago by mistake, I bent one of the tabs over and it broke off trying to bend it it back. I bought a NOS replacement but I never got around to installing it since you have to pull the water outlet pipe/thermostat housing to get at it. I ran it even in pretty cold weather that way a few times and it did well enough.

 

[Vern]

My fast idle solenoid keeps it at about 1000 rpm, but like big bart said it won't idle up on it's own. I don't know if its my spring arrangement but it will hold once you put it there. And cold start advance solenoid makes it nice and 'clatter-y'. Both these require the temp sensor, wiring, and GP controller to be intact. The controller does not have to be running the glow plugs.

In cold I'm to the floor with the pedal and off immediately after firing.

 

[TNBrett]

The glow plug controller is not necessary for either of the cold idle solenoids. It’s a very simple circuit, keyed power is supplied to the 2 prong temperature switch and then to the two solenoids. One advances the timing, and the other increases the idle speed. The idle speed solenoid was never intended to increase the idle speed on its own. It will hold it “open” though if you press the pedal.

 

[themechanicalford]

The glow plug controller is not necessary for either of the cold idle solenoids. It’s a very simple circuit, keyed power is supplied to the 2 prong temperature switch and then to the two solenoids. One advances the timing, and the other increases the idle speed. The idle speed solenoid was never intended to increase the idle speed on its own. It will hold it “open” though if you press the pedal.

You happen to have a pic of what they look like or where they are located so I can do some testing?

Also, are these parts still available as replacements? I thought I read somewhere that you couldn’t buy the cold idle solenoids anymore.

 

[Cubey]

You happen to have a pic of what they look like or where they are located so I can do some testing?

Also, are these parts still available as replacements? I thought I read somewhere that you couldn’t buy the cold idle solenoids anymore.

That's the temperature sensor and part number. It's buried down behind the pipe that points upward for the upper radiator hose to connect to.

You must be registered for see images attach

You must be registered for see images attach

 

[Cubey]

The broken one on my F250:

You must be registered for see images attach

 

[franklin2]

Starting procedure from my sunvisor, 1989 f250. Above 32 F hold the pedal halfway, below 32 F hold the pedal to the floor. You can barely make it out, but I think it says after it starts, lift your foot off the pedal and I guess the high idle solenoid will take over. I already have my idle speed higher than stock to help with the rollover noise from the zf transmission, so that might help mine. My high idle speed doesn't work, the sensor has been bad for years.

You must be registered for see images attach

PC280010 by D Franklin, on Flickr

 

[IH-GM IDI]

My cold start system is intact, I just 'set the choke' so to speak. One smooth motion to the floor and back off, while the glow plugs burn to let the high idle solenoid catch. I have it set for about 900rpm

 

[Cubey]

Starting procedure from my sunvisor, 1989 f250. Above 32 F hold the pedal halfway, below 32 F hold the pedal to the floor. You can barely make it out, but I think it says after it starts, lift your foot off the pedal and I guess the high idle solenoid will take over. I already have my idle speed higher than stock to help with the rollover noise from the zf transmission, so that might help mine. My high idle speed doesn't work, the sensor has been bad for years.

You must be registered for see images attach

PC280010 by D Franklin, on Flickr

I have held the pedal down before when it has had air intrusion symptoms (that went away on it's own. no idea why) since I figure that might help push out the air faster. Typically though, I don't need to. Might be I have when it was very cold too, just to help it a bit. My memory is swiss cheese a lot of the time so it's hard to recall for sure.

My cold start system is intact, I just 'set the choke' so to speak. One smooth motion to the floor and back off, while the glow plugs burn to let the high idle solenoid catch. I have it set for about 900rpm

Yep, I do the same. I can tell when it kicks off. It's harder to notice when driving unless you're at lower RPMs (25-30mph), then it feels like it lost just the tiniest amount of power. It's far more obvious at idle, I can hear a click and it the RPMs drop noticeably but not drastically.

 

[Big Bart]

Hey man I really appreciate the well thought out reply. I actuallly went to order glow plugs the other day and know that I need the motorcraft brand, but it looked like they were less than $10 on Rockauto and figured I must have had the wrong part, no?

I will search the inter webs for a good tutorial on checking the idle advance (I assume that is what is referred to as the high idle solenoid?). If you can think of any YouTube channels or good tutorials for checking it that would be great, if not I’ll start digging.

Have you ever heard this gurgle that I’m talking about? It sounded like air intrusion to me but it could also be something normal I suppose.

Fuel line o-rings were replaced about 7k miles ago, the previous owner took it to a shop. Don’t believe they replaced any lines though.

1) Not sure about the gurgling. To me it’s more of the the truck won’t start the first turn or starts and dies once or twice, then runs fine. That is when I feel I have air intrusion.
2) Was it the o-rings on the fuel lines to the lift pump or the return lines? If return lines they could be leaking again, especially if just the o-rings and not the caps and inter fuel lines. Or it has been 2-3 years ago. Often you can tell because the diesel seeps and makes the area wet ant it starts to collect dust and dirt.
3) I have not looked for Youtube videos, but take a look for both the idle soleniod and IP advance soleniod. You can physically see the idle solenoid, add 12+ and you can see it extend if you move the throttle back out of its way. If it does not move when you add +12v it is not working. I don’t recall if you can see the IP advance working. I have not looked for parts since mine are working but try O’Rielly’s, Ford, and Rock Auto. If not check with some of the IP rebuilders discussed on this site like Russ and Mel.
4) I have bought Motorcraft GP‘s from both O’Riellys and Rock Auto. ~$10 ea.

Let us know how it goes and post some pics.