Dyno day sucked!

[boost_boy]

Well guys/girls,

Finally got the car on the rollers and I could not even get to 1st base. I must've gotten like 18 pulls; trying to fast tune and figure why the damn car kept leaning out. We didn't want to think it was the fuel pump, so I kept adding fuel across the board to rescue my already busted dyno session. Car was making 255whp at 12psi, but was leaning out constantly. I got the nerve and tried to sneak a 5th gear pull and the dyno operator flew out there signaling me to stop and for good reason. The car was dangerously lean under 5th gear's load. At 6,650rpm, the car was @150mph and even though it was dangerously lean, it still was climbing. So I went out and raised the nismo F/P regulator to 52psi and the car made 271whp @ 12psi. The owners of the shop had me dry rev the car while they watched my F/P gauge and low and behold, the fuel was dropping as the boost came in. Their hypothesis was possibly the stock sentra fuel lines and/or the fuel pump. I guess I'll have to figure it out. I did have fun revving the hell out of that engine and the by-standers were loving the sound of the engine and the wickedly long gears. I'll try it again when I make some adjustments, but until then, fuel is the key. No fuel, no power .

Dee

[float_6969]

woot! keep us updated Dee! I have a question for you BTW. I'll shoot you an email...

[ISL33P]

sounds like a fuel pressure regulator to me. have you checked it out?

[wildacexxx]

im assuming u're running a afc. wat other mods are u running. those are good numbers and i might be aiming for that when i do go CA. run one of those fuel system cleaners. our cars are old and might have gunk stuck in there. also if u're pushing 12psi u should really upgrade that pump bro. good luck

[RMiller]

im assuming u're running a afc. wat other mods are u running. those are good numbers and i might be aiming for that when i do go CA. run one of those fuel system cleaners. our cars are old and might have gunk stuck in there. also if u're pushing 12psi u should really upgrade that pump bro. good luck

Ha. He has everything.

[boost_boy]

sounds like a fuel pressure regulator to me. have you checked it out?

Regulator is fine as it was tested whilst on the rollers by the shop technician.

Dee

[boost_boy]

im assuming u're running a afc. wat other mods are u running. those are good numbers and i might be aiming for that when i do go CA. run one of those fuel system cleaners. our cars are old and might have gunk stuck in there. also if u're pushing 12psi u should really upgrade that pump bro. good luck

No AFC here, bro. Mods are extensive with the major factor being a standalone, big turbo, big injectors, and a (for now) internally stock CA18DET. I also appreciate your concern wildacexxx, but I'm no stranger to performance or the CA series engine.

Dee

[81na ZX]

Were you able to see fuel pressure under boost? I didn't notifce it in your post, just the a/f... If your pressure is not rising w/ boost its either pump or fpr. and you tested your fpr....

If your seeing that 52psi @ idle, your lines are fine.

Could be bad/partially clogged injectors. But I'd test the pump first, then have the injectors sonically cleaned.

[boost_boy]

Were you able to see fuel pressure under boost? I didn't notifce it in your post, just the a/f... If your pressure is not rising w/ boost its either pump or fpr. and you tested your fpr....

If your seeing that 52psi @ idle, your lines are fine.

Could be bad/partially clogged injectors. But I'd test the pump first, then have the injectors sonically cleaned.

The injectors were cleaned prior to the swap back to a stock CA18DET. We actually raised the pressure to 52 psi @ idle to see if it would help correct the fuel issues. I then ran the car in 3rd gear and ran it partially throught the power band, then let it go. It netted 271.0whp and that was just partial way (around 5300rpm). They then told me to rev it while watching the fuel pressure gauge and they then told me to stop, concluding that it's either the F/P or the lines. I'm expecting this car to see at least 325whp @15psi.

Dee

[Turbogixxer]

Do a Volume test for the fuel pump and see if it can actually pump the volume it should. A fuel pump can keep high psi with low volume.

Check with the manufactor for the spec for the pump.

Regulator is fine as it was tested whilst on the rollers by the shop technician.

Recheck it, that does not mean he tested it right.

You may have hurt your motor running it lean like that, it depends on your a/f and timing.

[8ggalant]

has anyone who replied to this post read his sig lol...i think he was just postin to lett us know how the sentra did...not askin for advice....from what ive read this guy knows what he's doin..just my .02

[Turbogixxer]

has anyone who replied to this post read his sig lol...i think he was just postin to lett us know how the sentra did...not askin for advice....from what ive read this guy knows what he's doin..just my .02

Everyone needs help in one time or another. I am sure he does not know everything and/or seen everything. I am pretty sure he is a great guy and knows a lot.

[float_6969]

No, he knows everything and has seen everything. At least when it comes to the CA. IMHO, he's the most knowledgeable individual on the characteristics and behaviors of the CA in the US. Just MY $.02...

[fanta]

It'd be best to upgrade the lines no matter what.Minor setback, it'll all work itself out.

[c-rad]

I see some -6 or -8 AN lines in your future

[r34 gtr]

yeah, and a new walbro 255 at the least.

still, 271whp at 12 psi with gross underfuelling issues is freaking sweet. dee, that ca of yours is absolutely amazing and i congradulate you on that run. i doubt any other ca could have done that.

completely off the subject, (as usual) does anyone have a clue as to why my safcII won't read the correct rpm in? it is displaying it like my redline is 2000 rpm and idle is 550. the engine speed increases just like on my tach but seems to only be on a 1450rpm range. like, at 3000 rpm my safc will be displaying around 1100-1200 and at 6500 or so, its at about 1900. i dont think its a bad connection. is it just fubar or is something likely set wrong? thanks, and sorry about the question dee, i dont mean to try and hijack this thread. just figured i would post it where you would be sure to see it.

- tim

[81na ZX]

What are the diameters of your feed lines?

Most imports I've worked on have ~3/8 (9 or 10mm). Thats -6. Good for about 500hp under high pressure (i.e. boosted).Obviously your return lines are big enough if your able to control fuel pressures If they were too small, you couldn't turn the pressure down - i.e. youd be overflowing the stock lines.

So, if you have 3/8 lines, and can flow lower pressures (meaning no blockages), its definatly looking like a pump to me.

[c-rad]

completely off the subject, (as usual) does anyone have a clue as to why my safcII won't read the correct rpm in? it is displaying it like my redline is 2000 rpm and idle is 550. the engine speed increases just like on my tach but seems to only be on a 1450rpm range. like, at 3000 rpm my safc will be displaying around 1100-1200 and at 6500 or so, its at about 1900. i dont think its a bad connection. is it just fubar or is something likely set wrong? thanks, and sorry about the question dee, i dont mean to try and hijack this thread. just figured i would post it where you would be sure to see it.

- tim

Looks like you forgot to set it for 4cyls...

[float_6969]

You didn't change the number of cylinders setting to 4. I'll bet it's set for a 6cylinder...

[boost_boy]

I see some -6 or -8 AN lines in your future

Ahhh young grasshopper, you have great visions .

Dee

[boost_boy]

Do a Volume test for the fuel pump and see if it can actually pump the volume it should. A fuel pump can keep high psi with low volume.

Check with the manufactor for the spec for the pump.

Recheck it, that does not mean he tested it right.

You may have hurt your motor running it lean like that, it depends on your a/f and timing.

Everything you mentioned have been done and by all means are my friends who own the shop that house the dyno know what their doing; or my car wouldn't be sitting on their dynomometer. I already knew by the 3rd pull that my pump was tired, so I adjusted the f/p regulator for clarity. It is important that I test every aspect of my fuel system to include a wide range of parameter on my standalone to identify the unstable A/F ratio which had been so crisp during past dyno tests. I mean the pump is 7 y/o and was also a remanufactured unit, so it is definitely time to pull.

And no homey, I didn't hurt my engine not one bit. Timing is in a safe zone well and below what I normally run, so a lot of power is missing, but at least I can go another day to retune this engine. Vacuum still sits perfectly at 20hg, compression is sharp at 175psi per cylinder and the car doesn't puke oil through the exhaust valve cover's breather.

I don't claim to know everything, but when it comes to the CA18DET, I'm better off than most, but don't mind sharing my 8 years of CA18DET experience with the rest of the CA gang. I've paid my dues in this game....

Dee

[boost_boy]

What are the diameters of your feed lines?

Most imports I've worked on have ~3/8 (9 or 10mm). Thats -6. Good for about 500hp under high pressure (i.e. boosted).Obviously your return lines are big enough if your able to control fuel pressures If they were too small, you couldn't turn the pressure down - i.e. youd be overflowing the stock lines.

So, if you have 3/8 lines, and can flow lower pressures (meaning no blockages), its definatly looking like a pump to me.

I agree 81na ZX! I mean, the pump is just getting weak and has done it's job as far as I'm concerned. The fuel lines are stock, but are not crimped in any way. This car rarely gets moved, so I don't think much could've happened besides electrical issues helping to weaken the f/p ( I doubt this). it's just tired of faithful service.

Dee

[Turbogixxer]

No, he knows everything and has seen everything. At least when it comes to the CA.

There is no way to prove this OR show his true skill of CA. This close mind thinking is dumb. I am pretty sure he will learn from other people like people have learned from him.

Everything you mentioned have been done and by all means are my friends who own the shop that house the dyno know what their doing; or my car wouldn't be sitting on their dynomometer.

I say that because everyone makes a mistake. I am not questioning their skill.

I don't claim to know everything, but when it comes to the CA18DET, I'm better off than most, but don't mind sharing my 8 years of CA18DET experience with the rest of the CA gang. I've paid my dues in this game....

Great attitude. I am sure I will learn a lot about CA from you.

[Looneybomber]

Out of curiousity, what was the highest your A/F ratio got up to? Did it ever get past 15:1?

[float_6969]

There is no way to prove this OR show his true skill of CA. This close mind thinking is dumb. I am pretty sure he will learn from other people like people have learned from him.

The post was in a humorus tone. I've been on and around this board for a long time and am farily famaliar with the CA also, but am also well aware that I'm not nearly knowledgeable as Dee is. My statement was by no means meant to be taken literally. If you spend a little more time with us, I'm quite sure you'll quickly become familiar with my sense of humor/sarcasam. My statement was an opinion and that was clearly stated. I know that Dee doesn't know EVERYTHING, but from having known him on this board for as long as I have, I'm quite sure that he knows most of it. As was stated before, I believe his post was more for our information on the update of the status of his car than it was for help. I do appreciate everyone's kind imput as I'm also sure Dee is too. But I also believe that Dee is quite capable of sorting out his A/F ratio problems on his own if he needed too. If anything, this post will be helpful to any others later on down the road who may have a problem. I am not a narrow or closeminded person, and I am not apt to make such and absolute statement with out some sort of experience or information to back it up. I appreciate your candid response and I hope to see more input from you in the future. Thank you.

[JustinStrife]

And that sir, is why you are a Moderator.

*salutes Float*

btw Dee that's some nice numbers out of your CA even if you were having alot of fuel issues. As always, you rock.

[r34 gtr]

dee, for that engine you might want to consider using one of those high-volume trash pumps for a fuel pump. thats about the only thing i can think of that will satisfy your future fuelling needs. cant go wrong with around 100gpm.

and for the record, its set to 4cyl. thats what is so strange.

- tim

[float_6969]

And for the record, Tim is the guy in my sig....

[boost_boy]

Out of curiousity, what was the highest your A/F ratio got up to? Did it ever get past 15:1?

It surely did. If I can recall, I've seen it sneak to 15:8 on one pull. The pull in 5th gear had the engine pinging even with a partial mix of C16 and moderately conservative timing. One point of interest is the amount of effort it took to sort out a proper turbo for both spool-up speed and power. I've gone through about 5 different combinations and I think the one I have in the car now is marvelous. I mean, you can actually hear the thing spooling while driving along off boost. I won't reitterate what turbo I'm currently using because I've advised so many and some have gone their own routes. So I suggest using the search button and pan through the archives because that info is in there.

Dee

[boost_boy]

It surely did. If I can recall, I've seen it sneak to 15:8 on one pull. The pull in 5th gear had the engine pinging even with a partial mix of C16 and moderately conservative timing. One point of interest is the amount of effort it took to sort out a proper turbo for both spool-up speed and power. I've gone through about 5 different combinations and I think the one I have in the car now is marvelous. I mean, you can actually hear the thing spooling while driving along off boost. I won't reitterate what turbo I'm currently using because I've advised so many and some have gone their own routes. So I suggest using the search button and pan through the archives because that info is in there.

Dee

Turbogixxer, I am very amazed at how much sharing of information would benefit so many of our members. I actually sit back behind the scenes and let the younger guys pow-wow amongst each other and figure their own problems out amongst each other. "Ryan" a.k.a. float_6969 has come a long way in this field of nissan cars and engines and with that he's gained my respect as well. He's a moderator for a lot of reasons, but I think the main ones are because a. his desire to learn his engine/car has caught the eyes of the administrators and his peers ( like me) b. because he's extremely helpful c. he participates in nearly every discussion which makes him the all out post-whore of post-whores

I can be a know-it-all and bud into every conversation, but that's just not me. The burden of being the most knowledged about this engine on this forum is no longer one that I have to bear. Themadscientist's skills are sharp when it comes to the CA. Some of these guys know enough to get over and if they're wrong, someone's always around to correct misinformation. But as for knowledge of the CA DOHC series, I have enough of it to do what I want to do and answer as many questions as I possibly can.

The two other moderators on this board besides Ryan and Myself are sharp as hell because they both paid their dues as well. I see them write, I see no need for me to jump in because they can handle themselves. But when we have a member being disruptive, it is all of our duties as members and moderators to put and end to it.

I hope some day to be able to answer questions of yours. It will take a while for me to type the names of members whom I deem competent to tackle serious questions, but I assure you there isn't a question that can't be answered about the CA18DET whether anyone likes the answer or not.

The CA gang is great and I personally would like to formally welcome you to such a great community.

Dee