7.3 idi with a hypermax kit added. It was added by the previous owner. Engine was originally a NA. I’m getting low boost readings. The most boost I seem to be able to build is about 2-3lbs. It doesn’t seem to have the pep and boost it did when I first got the truck. Any ideas what could be causing this. Air filter was terribly dirty so I cleaned it thoroughly. But that doesn’t seem to be making much of a difference.
Low boost
- Thread starter culver21
- Start date
Thatoneguy
Full Access Member
Any boost leaks?
IDIBRONCO
IDIBRONCO
It could be a fuel delivery issue. If you're not getting enough fuel, you won't be able to build boost. You didn't say, but how long have you had the truck? You could try changing the fuel filter. It may not help, but it couldn't hurt, especially if you recently got the truck and have no idea how many miles are on the filter.
79jasper
Chickenhawk
Yeah, replace the fuel filter. And just replace the air filter. You said you cleaned it, so I would assume it's a k&n or similar. As normal paper element filters aren't really cleanable. Best to just replace them.
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Take a look at where the CDR used to mount on the back of the intake. My IDI didn't have a boost gauge, an when we tried to install one, it woundn't register. I found the original Hypermax kit would have had a rubber expansion plug to put in the CDR port on the factory intake, an mine is missing, so I am building boost, just most of it is blowing on the firewall.....
austin92
Full Access Member
I agree with these guys on what to look for and replace. Has the truck started smoking more or less since the boost started to drop? More smoke could be an up pipe leak or plugged air filter and less smoke could be a clogged fuel filter
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genscripter
Full Access Member
What are your EGT's? If they are low, you could just have your IP turned down, and by turning it up, you'll get more fuel, which means more power, which means the turbo will spool up more.
When I first put my hypermax on, my stock IP fuel screw setting was too low, so the boost was only reading < 3 psi no matter how much I hammed on it. I think i turned mine up something like 1.5 flats.
If your EGT's are normal or high, then you could have a timing issue. My Hypermax system (the van kit) tends to spoil up best at 4.5 deg BTDC. This was something I figured out after several performance tests trying to get my turbo to spoil up the best. I talked to Justin at R&D while I did this, in the hopes that we could find an optimal turbo timing setup for that van hypermax kit, which has nearly zero information about it on the net.
The last thing to look at are all the things the guys said above, but also, my hypermax doesn't provide boost unless I'm under a load. If you are just revving this in the driveway, it won't budge the boost gauge needle. Take your truck out on the road, put in some weight and measure your boost and EGT's then. That'll be a better test of your system.
When I first put my hypermax on, my stock IP fuel screw setting was too low, so the boost was only reading < 3 psi no matter how much I hammed on it. I think i turned mine up something like 1.5 flats.
If your EGT's are normal or high, then you could have a timing issue. My Hypermax system (the van kit) tends to spoil up best at 4.5 deg BTDC. This was something I figured out after several performance tests trying to get my turbo to spoil up the best. I talked to Justin at R&D while I did this, in the hopes that we could find an optimal turbo timing setup for that van hypermax kit, which has nearly zero information about it on the net.
The last thing to look at are all the things the guys said above, but also, my hypermax doesn't provide boost unless I'm under a load. If you are just revving this in the driveway, it won't budge the boost gauge needle. Take your truck out on the road, put in some weight and measure your boost and EGT's then. That'll be a better test of your system.
IDIBRONCO
IDIBRONCO
This is true and something I didn't think about. Since the OP said that the truck wasn't building boost like it was when he first bought it, I assume that he's doing something besides revving it in the driveway.
Well I can make 3-4psi in neutral just reving it, but most trucks won’t especially with stock fueling
79jasper
Chickenhawk
No way to know.
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79jasper
Chickenhawk
Timing meter. We have a timing meter thread somewhere.
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