GreenChevelleSS

Ok well I cant tell you for sure cause this is just what my friend told me over the phone.

He said when he pulled in his driveway the car spuddered and died. When he got out and checked there was fuel spraying out a vacuum line that popped off. Well I told him to check the FMU vacuum line and he said there was no fuel coming out its vacuum line. Well the line is down near the injectors but I havent seen it yet so when I do I can provide more details. When he pressurizes the fuel by turning on the fuel pump more fuel sprays out.
We where on out way home from the shop after jus changing to bosch red top 30# injectors.

The car has an FMU and aeromotive fuel pump.
Procharged to 10psi max and max fuel pressure at full boost is 70psi.

Im thinking the stock regulator popped or something broke on it but I dont know for sure im more of a carb guy, but I figured with the bigger injectors they would be using more fuel and causing the fuel pressure to be lower but Im not sure.

Please Help
Thanks
Danny

xpndbl3

iTrader: (5)

sounds like a fuel hose broke not a vacuum hose.

mean57

i would be willing to bet it is the fuel pressure regulator. if diaphram goes bad fuel in vac line will be evident. that is the one and only way fuel can get in a vac line on a fuel injected car. if it's not that it's a broken fuel line.

Vader

I'll second that guess. A ruptured diaphragm in the FPR would be the prime suspect.

GreenChevelleSS

Put in another one today, wasnt new but it was good and pressurized the line after the install and everything was good. We got it all back together and cleaned up agian after all the fuel came out. Well first off when we pressurized the line the pump kinda sounded funny when it pressurized and stopped it hadnt made that sound before. Well didnt think much of it at the time but got it all back together and started it. had just a little hard time starting but when it finally started idleing good, about 5 seconds after it started. Well all of a sudden it blew the vacuum line off agian and fuel started pouring out the regulator so now the second regulator is popped.

Were thinking maybe a clogged or kinked return line?
Does that sound reasonable but would that cause the fuel pump to sound funny when pressurizing? I know the tank isnt a vented tank so Im guessing it could but im not positive, Any feedback helps.

8Mike9

I dunno, think this color of shirt I'm wearing looks good on me?

Oh wait, you don't know what shirt I have on, nor what color it is.

You also don't know what I look like to judge it by.

Then again, all I know about your friends car is...about as much as you know about how I'm dressed.

GreenChevelleSS

do you need help?

8Mike9

Yes, I do help.

I just need to know simple little details...oh say,

WTF kinda car is it?

What injection system is it?

WTF vacuum line is the fuel coming from?

Then again, from your ever so descriptive post, I suppose I should know.


For all I know, you friend has a Fuel injected Ford Festiva.

Do I really need to ask specific questions to assist you? Or maybe you can just shed some light on the subject, after all it is your post and your problem, not mine.

I'm done.

Maybe I could have helped you, maybe not. But from this point forward, since I am obviously a lunatic, we will never know.

Treys_IROC

Thanks for the productive answer...

8Mike9

Why gee whiz, Trey.

Thanks for taking the time to quote me, instead of offering your own productive answer!!!

I'm sure I speak for everyone when I say...

Thanks BIG GUY!!!!

Treys_IROC

Lunatics are welcome to help as well, so dont worry about that.

8Mike9

Look guys, just do a search on my user name, and I'm sure you'll see I full of plenty of good advice.

Thing is, if you do not post a descriptive question, it makes ity really hard to help you out.

The more information you can add, the better.

I mean come on, "spraying fuel from a vacuum line"..and "what's the probelm"?

Is enough for someone to offer advice?

heck, wouldn''t you want to know What vacuum line fuel was coming out of, to make a educated guess at the problem?

That has to be the minimum information in my opinion.

Treys_IROC

Its my car, if i had an answer i would have already fixed the car... Any advice welcome, i answered your questions in my post where i quoted you.
Camaro 1989 IROC L-98 TPI gas is coming out the vaccuum line on the fuel pressure regulator.

GreenChevelleSS

Maybe you should look at the details more closely

8Mike9

Dude, I've been on this board from the time your momma weened you from her tit.

Don't welcome me.

Sit yor *** back and learn something beside what you can gather from Hot Rod magazine.

There's a few around here that have actually done things, without the glossy pictures and BS claims

Treys_IROC

You wanna start a pissing contest like 10 year olds its on, but seeing as how i want my problem solved i'd rather not get into it with you and have the post locked, i see that i rub you the wrong way and vice versa, so i plead with you, if your not going to help just dont bring this arguement out any further and i'll never bother you again...

8Mike9

I'm not arguing.

Just tell me:

Car

Fuel system

Which vacuum line fuel is coming out of.

Is that too hard?

As far as the above post about me not paying attention tom details, jimminy christmas, tell me what I missed?

sgapen

maybe someone should should check the feul pressure? to see what the pump is putting out?i thgink it should be 59 or 60 lbs total with return line blocked ive done this before on normal feul injection in the course of my daily job as mechanic peace out

8Mike9

How could anyone know it's either you BBC or your "putting a SC in a freinds..."

Car?

Treys_IROC

I apologize if i came off like a jerk, that was not my intention Car:1989 IROC-Z L-98 TPI; The vaccuum line coming off the factory fuel pressure regulator,

Thanks for any help you can provide,

Trey

8Mike9

Well heck, now one of the above suggestions makes perfect sense

The only way to get fuel into that vacuum line is via the FPR.

Either the AFPR was assembled incorrectly (diaphram cocked, etc), or the diaphram has ruptured inside.

See, now we are all friends

Very simple problem to diagnose and solve, with the above information.

GreenChevelleSS

Fuel Pressure was at about 43PSI when the engine wasnt running just from the pump pressurizing. When running with an 8:1 FMU at boost fuel pressure was going up to about 75-80psi. As you probably know the FMU restricts the return line during boost which increases the fuel pressure at the rails.

8Mike9

BTW Trey, no apologies necessary, I purposely do this on a somewhat frequent basis just to elicit a response

mean57

you guys type to fast. probably gonna need a stand alone pressure regulator for those kind of pressures.

Treys_IROC

We replaced the diaphram today, and it started spraying fuel again, which is leading us to believe that the return line could be kinked somewhere causing the pressure to build up...any comment on this, is this plausible or am i totally off base?

88TPI406GTA

I agree with 8Mike9.

There wasn't enough info posted to make a proper diagnosis and then the poster sounds like a pissy little girl when pressed for more info

I agree that FPR is the problem though...

I think that either an older diaphragm or bad install is the problem on the 2nd FPR.

How exactly would the return line get kinked? Simple enough to follow it all the way back and find out.

GreenChevelleSS

The pump is a aeromotive Tsunami if that helps any. its rated higher flow and pressure than a stock pump but is also working with the stock pump to create more fuel pressure.
How would you recommend checking the return line for flow? Where would I connect the air pressure line?

sgapen

maybe fmu is malfuctoining? its worth a look isnt it?

GreenChevelleSS

I just asked that if a kinked line sounded reasonable. I dont understand how that would affect what car it is. Then he posted something about what he was wearing which didnt make since till he posted his second post asking in english, not some riddle, that I could of told him what it was. He also called himseld a lunatic I just asked if he needed help.Anyway since is is a third gen forum I figured youd know that it was a third gen camaro. Also I said injectors which would usually mean a fuel injected car. But I would have supplied the details more clearly if someone would have just asked.

mean57

take lines off at both ends and try. not gonna hurt but won't tell all that well. if slightly kinked air will still go by. i would probably go stand alone pressure regulator myself with a super charger set-up. go to summit racing and search this part # MAA-4305M. not recommending this one but found it first.

GreenChevelleSS

I was thinking the same thing and im glad that you agree its something to look at. Thanks for just suppling simple things to check since we are just on here to get info on what we should check for

GreenChevelleSS

We were planning on doing a stand alone AFPR but for now we were gonna use the bandaid setup till more funds come in to change some other stuff.
Is there a line disconnect thats easy to get to that is near the tank?

sgapen

i would jack the car up and look by the tank you might need one of those clamp releases like chevy uses on the fuel filter a lot or maybe not hard to say

Vader

I'm looking at my calendar, and noticing that the full moon was LAST WEEK. Because of that, I'm not sure what's up with the membership.

That aside, if you have some reason to believe the fuel return line may have restriction, remove the return line at the rail and route it to a catch can (like a 5 gallon gasoline can) so no fuel can spill. If the regulator lasts more than a couple minutes, you may have some restriction.

Another possibility is that you have some damage in the regulator that is cutting or splitting the diaphragm. Knowing the peak fuel pressure would also be good. I read 75-80 PSI in your earlier post, but is that the FMU spec pressure or just what the instructions indicate? I'd be a little concerned about stock injectors at that pressure as well as the FPR.

sgapen

i dunno im feeling a brainfart comoing on so ill shut up now sorry i couldnt be more help good luck guys wish you all the best but sometimes its the simple things that screw people up so i would check the basics and then consult all data online or somthing of that nature

8Mike9

[QUOTE=Vader]I'm looking at my calendar, and noticing that the full moon was LAST WEEK. Because of that, I'm not sure what's up with the membership.

QUOTE]

Naw, not due to a full moon, I was just getting snippy after the 4th Silver Bullet

8Mike9

I don't think even a blocked return line would blow through the FPR, unless you had some serious pressure build up, my guess it would have to bwe in the 150+ PSI range to hurt anything.

Thing is, if there was no problem with fuel line blockage before the integration of the SuperCharger and FMU, AND the issue is too much pressure, then there has to be an installation error of some component.


I did a TPI swap on a '34 Chevy last year, the owner used a Walboro 255? pump.

Anyway, the truck had been sitting for a very long time, and these bug-like creatures had built a "tomb" in the fuel lines, essentially blocking off the return (we werere able to see the blockage on the supply side and corrected before we cycled it up). On test up we had 80 PSI fuel pressure, we cycled it to 80 PSI at least 30 times try to find the problem, with no ill effect to the AFPR (which used the stock diapharam that was probably 15 years old at least).

If you suspect blockage on the return line, a quick fuel pressure test would reveal it.

GreenChevelleSS

Well today we decided to try running without a regulator. We got it all back together hooked up a fuel pressure guage and while running we were at about 50psi and the needle was bouncing everywhere. The car was running super rich too. Well revved it up a tad and all of a sudden the needle starts going up and up and up till it pegged itself back on zero and kept going up and eventually bent the needle and screwed up the fuel pressure gauge. The car was pouring out black smoke and then Pop, blew up the return line before the regulator. All this happened so fast we didnt get the car turned off before something bad happened like the line popping.
Well we knew something bad was wrong but I checked all the lines and there were no kinks and I blew them all out with air pressure and they all blew out fine. So well I started thinking this FMU must be malfunctioning. We fixed the Blown line and bypassed the FMU. Still with no regulator in place. We started the car and all seemed ok at idle but fuel pressure couldnt be checked since the guage was now broke from the previous try. We looked at the A/F guage and at idle it was a bit lower than normal and then when we revved it, the A/F gauge stayed lean. Well we know that the FMU was now malfuntioning cause fuel pressure to be off the chart. We pulled the FMU and torn into finding that a tiny tiny piece of metal shot through the metal diaphram that limits the pressure. Well I guess that could be causing it not to open up and let off pressure (dont really know how this thing works).
We are ordered a new FPR and should be here tomorrow so we will get that installed and hook up another FP guage and see what we are running at without the FMU and also see what the A/F gauge is showing while driving.
Eventually were gonna put in a rising rate Adjustable Fuel Pressure regulator....hopefully pretty soon.
Thank you guys for your help and opinions or suggestions are welcome.

GreenChevelleSS

Ok we got a new Fuel Pressure regulator but when we installed it we put a shim behind it to up the fuel pressure at the rails. We then drove it for a while not boosting any and all seemed good, it does some some when you rev it which made me wonder but When we got on it and started boosting I noticed that the A/F guage was showing it richer than it was before with the smaller injectors and FMU install. We dont have the FMU installed because its screwed up but we were kinda worried about fuel pressure at higher RPMs and when boost is present. Guess its all working good now maybe we dont need an FMU. We need to go exchange our Fuel PRessure gauge so we can test fuel pressure at full boost...