boost question

[Harley]

I have just recently got my gauges hooked up and drove around town with no load. At idle theres no boost when you take off from a stop sign and get on it good max boost i get is 7 then at cruising speed goes back to about 1 psi. I have good vacum at the wastegate controller sometimes. what i mean is i just started my truck up and nothing no vacum, then reved it up and got vacum, so i plugged it up to the wastegate controller and then it pulls the gate and the arm to the front of the truck and holds it there. Not sure about that problem? Also i would like for someone to give details on this mechanical wastegate some of you are building. I run a machine shop im sure i can build it just don't know how. My orginal speedometer and tachometer will sometimes go crazy bouncing around, any clues on whats causing this? By the way its a stock vacum pump, but i have replaced the wastegate solenoid valve.

[grancito]

Sounds like a leak in the vacuum line, if not, check vacuum at the pump, it could have an internal leak. Please fill in your signature so we know more about your truck. It is probably 94, 95. The waste gate actuator should pull the gate lever forward as you described, so that is what the manual controller needs to do using a strong spring. Mine has a spring hooked over the actuator rod where it goes though the waste gate lever and is connected to an adjustable lever bolted to the turbo. I can send a photo tomorrow. Best give me your email address as the photo will be 450 kb and this site only accepts 70 kb. You can send to my private mail or Email.

[Harley]

I was gone all weekend so im just now geting to respond. thanks for the info i will check the vacum lines and pump psi. I made a signature before my last post but it didn't work so i just did another one maybe it will show up. I did tow my race rig to the track mon. night and the boost would go up to 9 when pushing it hard then fall fast to about 5 towing. trans temp got up to 210 and stayed there untill a few steep hills. egts done good only about twice went to 1100 then come back down. there is not one ounce of black smoke come out of this truck that i can see, and when you start it up in the morning its all white/blue smoke for a second or two then clears up.

[ZiGBlazer]

I'm having a similar problem, easiest way to tell if the problem is mechanical or electrical/computer is to swap the vacuum lines around at the wastegate solenoid or to run the vacuum line straight from the pump to the wastegate. Then drive it and see the difference.

My truck is / was similar, 95 k3500 drw auto. I don't know if that would be a common problem or some programming feature for a truck with those features.

Anyway, let me know what you find out.

[njdevi11]

http://www.sixfiveturbodiesel.com/showthread.php?t=411&highlight=waste+gate

This is how I made mine, only needed a hacksaw, torch and a drill, no machine shop required.

However I had the access to the tools I would have made a really nice looking one.

[Harley]

Thats good work, so all you do once you have a spring setup you adjust it untill you get the amount of boost you want? How much should you have? I don't want to blow it up at all just improve my pulling.

[grancito]

Thats good work, so all you do once you have a spring setup you adjust it untill you get the amount of boost you want? How much should you have? I don't want to blow it up at all just improve my pulling.

Did you receive my email, njdev11's design will get in the way of the filter if you have a standard one.

[Harley]

I got the pics, and yes now i see what you are doing. Nice design as well, So 12 psi is a good # to set it at? And thats while you are pulling a load correct? My fuel psi gauge is jumping from 5 to 6 lbs very fast. its a liquid filled gauge and its pulsating so fast its making bubbles in my gauge. any one know why its doing this?

[grancito]

The lift pump is a piston type, so that is the cause of the pulse. Your maximum boost with the boot down at any stage needs to be max 12 psi or you will get defueling after about 30 seconds.

[saddletramp]

Harley, your post from 5/26 7:23am pretty much describes exactly how this unit is designed to operate under load in stock trim. I have driven one for 13 years and tried many tricks and gotten lots of well intentioned advice. I always ended up with codes or defueling etc.. and was hesitant to 'chip' my truck for fear of compromising durablity.
Just this year I decided to 'chip' it and bought one, not from Walt, but his is probably good also. I am happier than ever!! This thing finally runs like I always thought it should. I am now topping same hills with the same loads at 65mph instead of 55mph and have pedal left to push and never a code. Best of all is the EGT is now approx 900 instead of 1100*, boost max is 12psi. Wish I had done this 13 years ago.
My advice to anyone is open up the intake and exhaust, upgrade water cooling to protect the heads, heat sink the PMD and spend the money to 'chip' it. If Detroit/GM had done that this engine would enjoy a lot better rep than it does now.