No boost when cold???

[JimScott]

I just installed a mechanical boost gauge (and EGT gauge) on my stock truck. I've noticed when first starting out in the morning it registers no boost. The EGT registers OK. It seems to start registering boost only after the truck is partly warmed up. Is that correct?

Jim

 

[KaiHartman]

I have a slightly different setup (Edge w/Attitude--"electronic" boost sensing) but have noticed very similar things... .



No boost (or very low, such as 2-3 psi even under acceleration) until a couple minutes of engine run time.





Perhaps the wastegate remains open under low pressures to prevent damage to a cold engine????

 

[nickleinonen]

boost only comes on when the engine is loaded. the ecm will limit engine fueling/load until it has reached a set operating minumum temp [don't know what that limit is]

 

[JimScott]

I have a slightly different setup (Edge w/Attitude--"electronic" boost sensing) but have noticed very similar things... .



No boost (or very low, such as 2-3 psi even under acceleration) until a couple minutes of engine run time.





Perhaps the wastegate remains open under low pressures to prevent damage to a cold engine????

Its more like 5 to 10 minutes run time. Before then the boost gauge doesn't even wiggle even under heavy load and acceleration. However the truck responds normally as if it has full boost.

Jim

 

[LRundberget]

That doesn't sound right. Mine registers boost as soon as I let out the clutch and start driving down the road. Since you say it responds normal, could it be the mechanical gauge is not reading until it gets warmed up? Have you checked out your gauge when cold with an alternate source of pressure?

 

[KaiHartman]

I just checked this morning, and my Attitude monitor claims under 4 psi EVEN UNDER LOAD until around 4-5 minutes run time. Of course, I am now in Texas and it's pretty warm out, even in the early morning... .



What gives?



Must be just a safety issue for the engine as I mentioned before, built into the stock truck program.



Perhaps yours is a different issue than mine... . but I have always thought that the Edge registers higher boost numbers than what a typical mechanical gauge might, just because of how it gets it's reading. So, I'm saying that if I had a mech. gauge installed, it may not register at all until the truck warmed up..... surely other people with mech. gauges can give ya some input about this

 

[RGramlow]

What kind of boost pressure are you guys with factory fueling seeing, I can get 30 psi and everyone tells me that isn't right, but I haven't taken the time to check the gauge, maybe they put the wrong face on ti at the factory, it is 0-60 psi, maybe it is suppose to be 0-35

 

[JTodd]

I can get just above 30lbs for a second then it drops back to ~28lbs steady. Thats running the Smarty on SW3. I always try to let the truck warm up for a few minutes before I jump in and run, but on the odd occassion have cranked and left. There doesnt seem to be any boost restrictions on my '06, it will build pressure right out of the end of the driveway.

 

[JimScott]

This morning the gauge registered boost right from the start. However, I had parked the truck in the garage last night so it was warmer from the start compared to the mornings when it registered no boost.

What kind of boost pressure are you guys with factory fueling seeing, I can get 30 psi and everyone tells me that isn't right, but I haven't taken the time to check the gauge, ...

Are you being told your boost is too high or too low?



Pulling my 5th wheel trailer (about 12,000#) on a hard pull it will register just over 30 pounds of boost. My truck is totally stock.



Jim

 

[DPashko]

you wont see any high boost pressures until the engine reaches a temperature of about 165*. Its and engine warm up feature programmed into your ECM. it will cut back fueling until that temperature is reached. it is easy to watch and try if you have an edge attitude monitor.

 

[KaiHartman]

you wont see any high boost pressures until the engine reaches a temperature of about 165*. Its and engine warm up feature programmed into your ECM. it will cut back fueling until that temperature is reached. it is easy to watch and try if you have an edge attitude monitor.

DPashko,



With all due respect, I was just wondering if you had any supporting data or info from Edge or another credible source to back up the statement? I have made similar conjectures but that's all they were since I could never back it up with any credible proof... . I totally agree with and support what you are saying, just wondering if there's anything to support it and back everyone up.

 

[RGramlow]

Are you being told your boost is too high or too low?



Pulling my 5th wheel trailer (about 12,000#) on a hard pull it will register just over 30 pounds of boost. My truck is totally stock.



Jim

I am told my boost is too high, but it will go up to just over 30 then settle in at about 28 or so, if I remember right, I haven't driven it too much in the past couple of weeks. Also what kind of pyro temps do you see with your stock pickup, I think for sure that my pyro probe could be bad, it will burry the pyro pretty easy pulling I would guess about 10-12000 pound enclosed snowmobile trailer down interstate through Montana with the cruise set on 80 I actually have a tough time keeping it under 1200 degrees even before I get to any big hills.

 

[JimScott]

I am told my boost is too high, but it will go up to just over 30 then settle in at about 28 or so, if I remember right, I haven't driven it too much in the past couple of weeks. Also what kind of pyro temps do you see with your stock pickup, I think for sure that my pyro probe could be bad, it will burry the pyro pretty easy pulling I would guess about 10-12000 pound enclosed snowmobile trailer down interstate through Montana with the cruise set on 80 I actually have a tough time keeping it under 1200 degrees even before I get to any big hills.

This is a late response to your message as I have been on vacation in Hawaii. Your boost numbers sound about right. My EGT would go up to about 1250*F with the boost just over 30 PSI. This is on a hard uphill pull (Mt. Hood Hwy in Oregon) with our 5th wheel in tow. I kept my eye on the EGT and backed off when it started to go over 1250, and that would drop the boost as well.

Jim

 

[RGramlow]

I see, that is what I was wondering, I am pretty sure my high temp were due to a problem I was having with the intercooler leaking, now i have a all welded cooler. Thanks alot.