Jakes and Injector questions

[Michael_e]

I'm working a little everyday to get my Scenicrusier rewired so i can move it under it's own power. Now to keep you current, i've had the old, tired, 8v71 replaced with a 8v92ta and it has Jakes installed. The Jakes question - how can i tell if the Jakes is a single off/on type of Jakes or a 2 stage where you can have half of the Jakes activated then have the full set of Jakes activated via a 3 position switch.
Next, when the engine was purchased, long ago, I was told it was a 425hp model 8v92ta. It was only today while snooping in the engine compartment that i removed one of the valve covers and noted that the injectors are a blue tag 9a90 series injector. Is this the right injector for a 425 hp 8v92ta?

Thanks,

Mike

[Nick Badame Refrig/ACC]

Hi Michael,

What makes a 2 stage or Hi/Low Jakes are weather one bank is enguaged or two.

A 3 position switch will make or brake the current to left and right bank of selonoids. Or bring them both on together.

I installed a 3 position switch on my jakes but, I never use low, always both banks on because I don't seem to notice

just one bank on. Maybe because I have an automatic trans.

Don't know much about the injector color but, Tom C. would..

Good Luck
Nick-

[blue_goose]

9A90 is good, you can go larger and just make more black smoke.  They should give you all you need in the engine.  If you rolled the power back you would be just as good and not use as much fuel.
Jack

[Michael_e]

Nick - Thanks for the 'in use' type of answer. I also have an allison 754, so your answer really helps.

Jack - Thanks. But i'm not exactly sure what you mean by 'rolled the poser back.' Do you mean using the next smaller injectors of just using more gentle control with the right foot?

Mike

[TomC]

Blue 9A90's are clean tip injectors.  If you have the retarded cam California version, you'll have 424hp and 1205lb/ft torque.  If you have the standard timing federal version it will be 435hp and 1235lb/ft torque.  Before installing, it would be good to have a mechanic pull the gear train cover and set it to the federal version timing-better performance and fuel mileage.
The Jake brakes should be wired like this- have a ignition switched power source at the engine to first go through the governor micro switch then up to the dash board.  There you can have an off/on/off switch so up position is both heads and down is just one head.  Then lead those two wires back to the engine to control the jakes.  Using a three wire extension cord works well.

Along those lines, a few months ago, I bought 5 different colored 50ft extension cords and ran them from the engine compartment to the drivers compartment.  Now I have wiring in place for and additional gauges or controls I might want to add.  So far I've used two wires for the cruise control and two more for tachometer.  I cut the female cord 4 feet back from the plug and installed the extension cords with the plugs at the fire wall.  So now if the engine has to be removed, just unplug the extension cords and replug them back in since they are color coded. Good luck, TomC

[Michael_e]

Tom - Unfortunately the engine is already installed. Is there any other way to tell whether the engine is timed standard federal or retarded california. Hummmm, i just reread that last sentence, but i'm sure you know what i mean.

I think i understand your wiring details. And thanks for the extention cord ideas.

Mike

[TomC]

I'll try to ask Don Fairchild that question today about federal or retarded California.  Good Luck, TomC

[TomC]

Just talked to Don and about the only way you can tell the cam timing is if the engine is still in its' original configuration from the factory and then run the serial number.  The serial number is behind the water pump on the block.  Good Luck, TomC

[Michael_e]

Tom C - one more question, what do you mean that Blue 9a90 are clean tip injectors? I tried several different searches about clean tip injectors and didn't really come up with an explanation. I did find plenty of sites selling stuff to clean injectors. Is there a good site to go to that explains this?

Mike

[TomC]

Blue tag in reference to the clean tip means it has an extra check valve in the tip to prevent it from dribbling between injection strokes.  At the time, it was the cleanest injector Detroit had for the always tight California smog rules.  Good Luck, TomC

[Michael_e]

I've be been chasing down the jakes wiring today. And i need help identifing something. See pic 1. This thing seems to control the jakes in some manner. It appears to thread into the side of the governor housing and has an air line on the other end controlled by a valve and electric switch (skinner valve??) there are two black wires connected on one terminal and they go to each head and to the jakes control head(?). The yellow wire heads north and i'm guessing it goes to a on/off switch near the drivers seat. What is this thing and are my assumptions close? Also, where would i wire in that skinner valve that i mentioned earlier.

And while in the engine compartment i noticed that on the right theromstat housing there are two temperature probes and the left housing doesn't nave any. Why would this be configured this way? See pic 2

Mike

[JackConrad]

  That switch is the Jake Brake buffer switch with the fast idle option. One thermostat housing should have an alarmstat (for hot engine shutdown/alarm). The other thermostat housing should have a similar alarmstat as well as a sender for the temperature gauge on the dash.  This is a minimum. Our 8V71 each thermostat housing has an alarmstat sender as well as a gauge sender for the 2 gauges on the dash, as well as an additional sender in one housing for the mechanical temperature gauge in the engine compartment.  Jack

[Michael_e]

Thanks Jack. The fast idle option  - is that controlled by the air line coming in to the left end of the Jake Buffer switch? If so, to make it work i just need to wire up a on/off switch up front? Is there a good web site to read about this?

For everyone, i would look some of this up in some of my books, but, i thought we would have had our house sold by now and have moved to Kansas as we had planned. I have already moved a lot of out stuff to a garage we purchased at the first of the year. It seems like every book i need or tool or whatever, is now there, not here. Let me tell you that this sucks, being 1/2 moved and then stalled out. But, things WILL get worked out. Just not as soon as i had planned.

Mike

[JackConrad]

Thanks Jack. The fast idle option  - is that controlled by the air line coming in to the left end of the Jake Buffer switch? If so, to make it work i just need to wire up a on/off switch up front? Is there a good web site to read about this?
Mike

The air to the fast idle is controlled by a solenoid (ususally installed next to the engine stop solenoid. These solenoids are controlled by electrical switches. For Jake Brake information www.jakebrake.com   Jack