[sandnut]

I shouldn't say no smoke, but hardly any now.
I have a DI regulated return that normally is at 66 or so PSI, with an in dash gauge. On Saturday I changed the oil & washed off the top of the engine. Monday I drove it & noticed that that my PSI was suddenly over 100 #'s. I did a little tinkering & finally just adjusted the regulator until the gauge read 68 psi. The next day, I noticed that it started off at 80 #'s, then dropped to 70 once the engine warmed up. It now stays steady at 70-72 #'s.
Anyway, I suspect something is wrong with the gauge, but I also noticed that when I get on it hard, I get just a little puff of smoke & that's it. Even when I lug the motor in 4th gear (which used to create a huge black cloud if smoke until the turbo got going), I get almost nothing. Why/how would a (possible) fuel pressure change or oil change do that?
Keep in mind, I like less smoke, so I am happy with this change. The trucks performance seems to be the same, I just am trying to figure out what caused this change, and make sure that whatever changed won't cause problems later on.

 

[hotwheels]

Hard saying. I'd check the regulator out. Maybe it's got some gunk in it plugging it up creating the higher pressure. I know I lost about 20 hp or so when I ran my fuel pressure up to 80 psi vs about 60 and I had a rolling idle that would kill the engine when comming down to a stop sometimes at 60 psi that went away when I dropped it down to 40. Hard saying but it could be something with the fuel pressure being all out of wack.

 

[Charles]

Anytime you just Lose ALL smoke in an instant, first check should be that the map sensor hose is not blown off. If you've got a scanner, check the map sensor input assuming the hose is still connected.


On Edit:

I dropped my fuel pressure from 68 to 60 in an effort to make the A-1000 last, and dropped a TON of tailpipe smoke, and the engine was much more crisp. It also dynoed an additional 60rwhp.....but that might have been the compounds, who knows . It did drop a bunch of smoke and crispen up on the fuel pressure drop though.

 

[Deputydog]

Yep what Charles said. It happened to me once..

 

[sandnut]

Thanks for the info guys.

 

[jtharvey]

What location are you guys using to set your fuel pressure? I've got a mechanical gauge on the regulator, and an electric in-cab gauge with the sending unit on the y-block before the heads. I notice about 4 psi of difference between the two, with the in-cab gauge reading lower.

 

[gregrob]

That's because of the pressure drop running it through the heads and what injectors use.

I would always set it on the return, after it has flown through the heads.

 

[jtharvey]

I knew why the pressure drop was there....I just wondered which location you guys were using. I assumed it was on the regulator, but you know what assuming can do...

 

[gregrob]

LOL, I feel ya man.

In talking with Dennis, best place is after the heads on the regulator. That's where I would say most everyone with the Aeromotive regulator is running it due to the gauge being on the reg itself.

So IMO, best place is on the reg.

 

[jtharvey]

Since that's basically the setup I have, I'll start playing with my FP a little. It's set at 68 on the regulator right now, so I'll drop it to 64 for a week or so then down to 60 and see how she runs.

 

[hotwheels]

I dropped my fuel pressure from 68 to 60 in an effort to make the A-1000 last, and dropped a TON of tailpipe smoke, and the engine was much more crisp. It also dynoed an additional 60rwhp.....but that might have been the compounds, who knows . It did drop a bunch of smoke and crispen up on the fuel pressure drop though.

I was playing with fuel pressure on the dyno and found I lost 20 or so hp with it at 80 up from about 45. Then I dropped it back to about 60 and gained the power back. I had a nasty rolling idle for awhile so I dropped the fuel pressure down to about 38 at idle and hooked up the boost compensator to the MAP side of my MAP regulator so it increases to 60 and stops at WOT and my rolling idle went completely away. IMHO very high fuel pressure isn't very good.

 

[Dieselfever]

MAP side being: between the sensor and the overboost fooler thingy?
Or
Being: between the actual manifold and the overboost fooler?

I'm getting it as the manifold side so it gets all absolute pressure, but How much boost will an Aeromotive regulator handle in it??

-Michael

 

[hotwheels]

MAP side being: between the sensor and the overboost fooler thingy?
Or
Being: between the actual manifold and the overboost fooler?

I'm getting it as the manifold side so it gets all absolute pressure, but How much boost will an Aeromotive regulator handle in it??

-Michael

Map side as in on the map side of the boost regulator. That way it only sees how much boost my map sensor sees. This bumps the pressure up to right at about 60 psi from just under 40 psi at idle. Otherwise I'd be pushing it up to the 80 psi range where I actually saw power loss.

 

[jtharvey]

How much boost will an Aeromotive regulator handle in it??

I went round and round emailing with an Aeromotive tech with that exact same question. It took several emails for him to give me an a straight answer, if you could call it that. But, he said that since it's your boost pressure that's raising the fuel pressure, boost pressure on one side of the diaphram = fuel pressure on the other side, it doesn't put any extra pressure on the diaphram and it can handle whatever you throw at it.