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Hurley88E9

E9 Reversing Valve / Puff Limiter

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My 1988 Superliner with an E9 and V style pump does not seem to run like it has the advertised 500Hp. I just put new injection nozzles in it a few months ago. It does not smoke at all under any circumstances other than when the parking brake is set and you floor the accelerator pedal. I have never seen EGTs get much over 900 on a heavy pull. There also does not seem to be a lot of whistle from the turbo when its under a heavy load like it could stand to have more fuel.

Today I pulled the puff limiter out. The PLE dimension stamped on the pump housing is 1.086. The set PLE dimension Measured 1.010. I would think that being that much shorter would allow the rack to travel fully. I decided to throw a .020 shim in it just to see what would happen so my current PLE is .990 and its supposed to be 1.086.

Also I removed the air line that supplies the puff limiter. With the truck aired up and the parking brake released air comes out of the reversing valve. My reversing valve is mounted on the manifold and has one air line that supplies air to the  valve, one port connected to the manifold and then the port that supplies air to the puff limiter. I removed the valve from the manifold and connected a pressure tester to the port that connects to the manifold. I also inserted a test fitting in the port that goes to the puff limiter. When the manifold pressure was set at 15 psi the valve supplied 15 psi to the puff limiter. When manifold pressure was increased to 20 psi, 8 psi was supplied to puff limiter. When manifold pressure was increased to 25 psi, 4 psi was supplied to the puff limiter. Puff limiter would fully extend when 20-25 psi was applied.

Does all this data sound correct? My concern is the reversing valve is allowing to much pressure to go to the puff limiter causing the fuel rack to not go full throttle. 

I have not checked boost pressure but i did install a test fitting so the next time its driven i will record boost pressure. I dont think there are any leaks in the intake due to the fact i have no smoke.

 

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If I was you first check that your throtle lever is going to full fuel ( Breaking over the spring at the end of stroke!) make sure your stop lever is going full OFF ! and check that you have ( at  least)  25 PSI fuel preasure UNDER LOAD! before getting carried away with testing any more the shim you added should have increased the smoke on take off some! A whisper of gray black smoke on take off would be ok in my view, however some may disagree! 

Also the little slave should be fully retracted by 25 psi boost! There is also a cap on the opposite rack that (MAY ) have a small piston and a light spring under it pull it and check the piston is not binding under that cap!!

Edited by fjh

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Well that's the idea right,the more manifold pressure the less going to be he puff limiter,with only four pounds the rack would be able to push back the plunger and open more fully,I think.. A lot f people run a line into the cab with a switch so u can shut it off but then turn it back n if you have to.

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3 minutes ago, MACKS said:

Well that's the idea right,the more manifold pressure the less going to be he puff limiter,with only four pounds the rack would be able to push back the plunger and open more fully,I think.. A lot f people run a line into the cab with a switch so u can shut it off but then turn it back n if you have to.

That is the way a puff limiter works best, turned off! The throttle by cable works best for me as well. Not recommending this setup for a truck that sever people drive. The response is like instantiations instead of waiting for something to happen, you do get the black puff though. I do not like an air throttle with puff limiter, the engine is sluggish and does not have the power at first press of the throttle. Disabled puff limiter and only time it is on is for emissions check. 

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I checked that the throttle was going full and the stop cable was fully retracted before i did anything. I will pop the cap off the other rack and see what i have.

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6 hours ago, MACKS said:

Well that's the idea right,the more manifold pressure the less going to be he puff limiter,with only four pounds the rack would be able to push back the plunger and open more fully,I think.. A lot f people run a line into the cab with a switch so u can shut it off but then turn it back n if you have to.

That is what I did on my 88 R Model. It originally had a 12 speed but was changed to a 15 speed Eaton before I got it. So I used the air switch for the extended range.

And when i was a company driver switching trucks all the time, I always kept a tool box full of roofing nails to plug off the air line at the puff limiter. Worked perfect! LOL.

It was better using the switch though. Because then you can have black smoke and tail lights but if the MTO/DOT pulled you in, flip the switch and no smoke at all. Wouldn't pull itself empty, but no smoke for them to harass you.

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Today I ran the truck with a boost gauge hooked up. A heavy up hill pull only made 18-19 psi, that was the most i could get out of it. The relay valve is probably still supplying 10psi of air pressure to the puff limiter when the engine makes 18 psi of boost. Truck still does not smoke at all since i put added the additional .020 shim to the PLE dimension.

Im wondering if the relay valve is the issue.

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Take the bimbo slave out cap the hole and run it and see what boost it makes The threads of the bimbo hole are  9/16 fine if you want to plug it permanent like!😉 

Edited by fjh

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