I finally finished installing a Hypermax kit on my 1992 E-350.


"Boost gauge: Hmmm. I thought it wasn't reading but once on the road I do get a read, sort of. It maxed out at about 2psi when "on it", but usually reads zero, or so close to it I can't tell the difference, and I can't imagine I'm getting that little boost. EGTs run between 800-1000 on the highway depending on speed and load and I didn't think the idi could pump out those temps without some boost going on. I wouldn't think 2 psi would do it.

So, either the gauge is hosed, or the hose is hosed, or Ive got a serious case of boost leak. But again, if I wasn't actually getting the boost, could I be running those kinds of EGTs?

I'm going to check over the intake cap and the boot joining the turbo to it and see if anything jumps out."


I posted the above in my build thread over on Expo-portal, but the idi specific knowledge base is way better over here so....


I pulled the dog house and checked out the boot that connects the turbo to the intake cap and I cant feel any leakage. The cap seams to be sealed to the intake ok, at least I cant feel any leaking around it.

I know when a boot split on my 6.4 you knew that sucker was leaking in no uncertain terms.

I pulled the boost gauge fitting from the top of that intake cap expecting to get some significant positive pressure spewing from it and there is essentially nothing. It's almost as if there is no boost pressure at all. Would this be normal, even just at idle?

I hooked my boost gauge to positive pressure just for giggles and the needle seems to swing free.


I have -zero- experience working on an idi or diesels in general so I am totally flying blind here. Not even sure I'm posting helpful info, but I could sure use a helping hand on this one.

 

Do you have the pump turned up at all? A NA IDI can see 800-1000 all day long. Boost actually lowers EGTs, to an extent, as it takes away the over-rich condition. My leaky 088 is doing 6-7psi with a NA cal. pump, so even with not being turned up, you should be seeing more than that. Get a good electric sender gauge. Even so, sounds like you have a pretty serious leak somewhere.

 

I had trouble getting the right combo of tools to turn up the fuel screw so in the end didn't get a solid count on how many flats, but I'm thinking at least 2. I know under load I get some black smoke now where before I had none no matter what I did.

I thought about a leak, but I figured I'd have to be leaking something fierce and it would be noticeable. Right now there is nothing that just jumps out and says "I'm a serious freakin leak!".

I didn't mess with the timing at all, but the install sheet didnt say anything about adjusting it, so I figured I'd leave it be. At least for now.

I guess tomorrow I'll pull the intake manifold cover back off and check the o-ring and the boot.
Beyond that I'm at a loss. Where else should I look for a boost leak?

 

Where is your waste gate hooked into? There will be no pressure at idle or really even revving.

Also stock na timing is like 9.5 with turbo it should be around 7

 

No waste gate on this system. Timing is unknown. I dont imagine it was ever adjusted from factory but I couldnt swear and I have no real way to check it, short of forking out the money for the timing adapter and a compatible timing light. A little reluctant to do that since it's not something I see a consistent use for.

I know how to adjust it, and how much to get 2 degrees (or so they say), but without the actual tools I'm really just guessing.

Funny thing is it seems like the more I drive it the more boost it's starting to show.

Today I checked everything I could think of for leaks (found none) and decided to head to Summit for another boost gauge on the off chance the one I had was bad. Trip up showed more boost than yesterday, which was pretty much none, topping out at about 3 psi.

I swapped boost gauges (no change) and headed home. Boost maxed out at 6psi but that was with a pretty good load on it. Not sure what's up with that. The up pipes seemed to be sealed in the turbo pedestal just fine, but thats at idle in my garage. Maybe on the road there was exhaust leakage and the turbo wasnt getting spun the way it should, and now they're sealing up better.

No clue. Grasping at straws for the most part, but I'm thinking it might just be a tuning issue at this point.

 

it really sounds to me like you have a leak. it could be on the exhaust side causing the turbo to not spool up. as you drive it soots up and is getting better. do you have the doghouse off to see the up pipes while driving?

 

there will be almost no boost unless the engine is under load. and "under load" does not mean driving around, it means pulling a hill with 2000 lbs in the back.
i will only see 1-2 lbs boost with my banks non wastegated unit, but can see over 15 lbs boost under load.

 

Was there a decent performance increase?

 

This is where I'm running into trouble I think. I'm getting conflicting info. Some guys are seeing what I'm seeing and saying its normal, but then there's others saying they see 5-6 psi just cruising on the highway, and up to 15 under a good load. I'm having a hard time cracking 5 psi, and even harder time figuring out who's "right".

I know, I'm "unloaded", but define loaded. What does your standard run of the mill E-series weigh? My unit runs 10.5k with not much in it besides me. I'll bet that's in the neighborhood of a ton over a regular van.

I think the exhaust leak might have been at least part of it. Sitting in my drive I couldn't see or feel any leakage, and didn't see any driving down the road ( no doghouse yes), but maybe there wasn't enough load on it. Don't know. The only leakage I could see was on the exhaust side of the turbo at the downpipe. I'd get a puff of smoke coming from that connection if I romped in it.


I appreciate everyone's input and regardless of this issue have learned useful stuff, like egt for a NA idi. I figured 800-1000 would be high, but turns out not.

Right now I'm thinking I need to check/adjust timing, and figure out where my fuel is at. Is there a way to baseline that screw and then X amount of flats is stock, adjust from there for turbo?


Anybody know of an idi guru in the Canton/Akron/Cleveland area of Ohio? And a Dyno that can eat a 10.5k Ambo w/6" of lift on 37" tires?

 

I can feel i, but nothing that made go "Holy Screamin Eagle Chit, what a diff!".

 

if the exhaust leak is on the outlet side, or after the turbo, that will not effect boost.
my 88 weighs 9700 lbs. normal driving sees very little boost, sometimes does not even move the gauge, even with no mufflers on the 4 inch pipes. put a 17,000 lb mini excavator on the trailer behind it and i can pin the 15 lb boost gauge climbing one of the bridges over a river up the road. .

 

I have a noticeable exhaust leak at my factory turbo up pipe and i see 1psi at 60mph, 2psi at 65-70mph in an 8700lb truck. The max i see is 6psi with all of the leaks. I'm currently installing bull moose, misters, air to water IC, and new up pipes.

 

What kind of EGTs you seeing with that 17k on and 15 psi? If I'm on mine up a hill, and seeing that 4-5psi, I can touch 1100 if the hill is of any length.

Just curious. My 6.4 could crack 45psi up a hill with that kind of load and I wanted to run the speed limit. EGTs would start to get ugly as well, but boy that sucker could pull.

 

i get out of it around 1200 degrees.
but i usually only see around 1100 or so. i have my pump set for a very slight haze of smoke at full throttle going uphill.
my 05 kenworth will push 70 psi boost with the 475hp twin turbo kitty cat

 

Easiest way to find a leak is to start it cold with minimal if any glow time. The heavy light grey smoke will make leaks stand out.