1991 IDI with Hypermax turbo kit questions..

[SS90]

Hi everyone,

Stumbled upon this site while researching things about the new truck I just picked up. It's a 91 F350 Dually ZF5 trans, 120k miles with a Hypermax turbo kit. Here's a brief summary about what I know about the truck. Had a Hypermax turbo kit put on back in 05. Prior owner had some medical conditions that didnt allow him to drive the truck after that, so it sat tucked away in a garage for 9 years until last year the new owner bought it. It was a no start deal, and had been taken into a diesel shop and they found rust in the injection pump, so the pump was replaced, along with the injectors and glowplugs. I believe the tanks were dropped and flushed as well. This was done last fall.

Fast forward to Last week. I checked the truck out and couldn't pass it up, super clean and seems to run really good for an old girl. I did however notice when driving it watching the boost gauge that it was real tough to hit 5-6lbs of boost, and that was near 3k rpms in 3rd-4th gear. Didnt notice it blowing any smoke either. EGT's near 1000ish maybe a little higher. Thought that was awful low for boost numbers.

Today I gave hypermax a call to explain what was going on, and he asked me if the truck was blowing a black smoke and I told him no. He advised that the pump probable needs to be turned up and that it should be making around 12lbs of boost.

The previous owner included receipts for the recent fuel system work that was done so I called the shop up to ask a few questions. He advised me that the injection pump that was installed is 20% over stock (not sure if that means it was turned up a couple flats or that the pump comes from the manufacturer with a higher calibration then stock?) And that the injectors were replaced with factory IDI turbo injectors from a 94 model.

Should I try turning up the pump a couple more flats on the hex? Would giving it more fuel give me more boost?

I have yet to pull the air cleaner off to see if there are any loose connections on the compressor outlet or maybe a worn boot or something. Just would like some insight before I dive into the project. I bought the truck to haul ~7k pound load on weekends. I sold my 99 PSD which towed great, I'm hoping this will do better being a dually.

Thanks!

 

[cpdenton]

A few things to check. Have a good look at all the intake piping between the turbo and the engine. Look for anything that might be loose there. When it's all good and tight, check all the exhaust piping. Look for black soot around any joints in the exhaust pipe pre-turbo.

I am always leery of a pump that is "20 percent over stock". All the GOOD pumps I have seen are calibrated by the actual cc's of fuel they put out, not in comparison to "stock".

Stock calibration is around 65 cc's of fuel, whereas my moose junior pump is 90 cc's of fuel. That is about 40 percent I think just for a number there.

The EGTs do seem a little high for the boost number though.

Timing might be something very important to check as well. These pumps do have a timing spec that needs to be hit. You can't do this by ear either. Only the proper equipment can set the proper timing. Most people agree that is between 7 and 9 degrees BTDC. Ask the shop how they set the timing on the pump as well. Do a search here for timing using a pulse meter.

 

[icanfixall]

Welcome to the forum. What needs to be known is what turbo is on the engine. Is it a wastegated turbo or not. a non gated turbo wont make the same boost a gated one will. As for turning up the fule I suggest holding back till you know for sure there are no boost or exhaust leaks. both will limit your boost numbers. As already posted. Any exhaust leaks show up as black soot around joints. An intake boost leak shows up as an oily joint.

 

[SS90]

Welcome to the forum. What needs to be known is what turbo is on the engine. Is it a wastegated turbo or not. a non gated turbo wont make the same boost a gated one will. As for turning up the fule I suggest holding back till you know for sure there are no boost or exhaust leaks. both will limit your boost numbers. As already posted. Any exhaust leaks show up as black soot around joints. An intake boost leak shows up as an oily joint.

i


Non wastegated turbo. And you would think that if there was a loose intake or exhaust pipe that it would be puffing smoke because of the lack of air coming into the cylinders which is supposed to be getting more fuel if it has bigger injectors and a turned up pump

 

[ToughOldFord]

Hypermax sells 2 types of turbo systems for the IDI, a 'conventional' and a 'pulse'. I'm pretty sure neither is waste gated. I have the pulse and it is not.

 

[Black dawg]

I would get the timing set, so you have a baseline. Sounds like there is room for more fuel, egt doesnt always get higher (atleast proportionally to the amount of fuel) with more fuel on a non wastegated turbo. More fuel = more boost. Just watch temperatures towing (egt and coolant).

 

[FarmerFrank]

Check the air filter. I've been playing with differnt air cleaners on my hypermax kit and if they are too restrictive my egts go sky high. Like 1100-1200 holding 75mph up little hills and 900 on the flat.

And I agree, you need more fuel. A little haze at wot is about right

 

[SS90]

Check the air filter. I've been playing with differnt air cleaners on my hypermax kit and if they are too restrictive my egts go sky high. Like 1100-1200 holding 75mph up little hills and 900 on the flat.

And I agree, you need more fuel. A little haze at wot is about right

I pulled the aircleaner today and it has a K&N filter in it. It looked clean as well.

I pulled the whole air cleaner assembly and the clamps from the turbo boot to intake are tight. Couldn't see any holes or anything. A little bit of oil on the boot itself. I looks like there is oil coming from the Hypermax hat that bolts to the intake, leaking onto the top of the intake. Not too bad of a leak but it is wet there. I'm curious to if the turbo seals are leaking into the intake.

 

[TahoeTom]

Behind your air filter housing on the intake before turbo should be a tuna can looking fitting with a hose into it. That is the CDR (crankcase depression regulator). Blowby from the crankcase is recirculated through the CDR and back into the intake. The Hypermax kit takes the vapor from the valve cover on drivers side to the CDR. Blowby has oil mist which ends up in your turbo and intake. The stock NA configuration uses the same CDR mounted directly behind the intake. The turbo oil drain into the valley pan is where the crankcase pressure gets to the CDR on an NA engine. Oil into the intake is the nature of the beast. Our engines burn the oil and the CDR shuts off the suction of blowby if the air filter becomes blocked. An alternative is some sort of oil catch can to try and get the oil to be separated from the air before it gets to the CDR. Some folks run a road draft tube (RDT) and let it vent to atmosphere, somewhere under the truck where the air passing over it creates enough vacuum to draw it out. The RDT will have visible smoke when not moving and may drip oil when parked.
Here is a thread on this. The last post links to another post with some catch can and RDT ideas.
http://www.oilburners.net/forums/sh...ck-Question-About-Blow-By&highlight=catch+can