Ok I did the mightyvac hook up with a T to my Boost gauge and the other side to the Cartech and brought it up to 10 psi...the fuel pressure went right up to 48 psi and held there..I start screwing in the center set screw, herd a little hiss whine from the cartech and thats it...I checked inside for fuel pressure and I got NO change on the fuel pressure gauge...I had the Screw all the way in and still receiveing 48 psi on the fuel pressure gauge and a still holding 10psi on the boost gauge...what gives ??
Could it be the fuel pressure sender for the gauge...I turn the car on ACC it shoots to 40..then when I start it reads 34...I gas it a tiny bit and I get minimal change...what gives..I wanna drive my car already

It cant be a boost problem because that is holding very well..im clueless

What am I doing wrong ?? Maybe the Fuel pressure sender is bad, or the actual Cartech is bad ??

-matt

 

When you are pumping the mityvac to apply pressure to the fmu, you are doing it with the engine running, right?

 

Yea engine is running...Im trying to ponder what could be wrong

possibly a fuel sender problem....the cartech is bad ?? im lost

-matt

 

Okay, next thing to check is how the fuel lines are connected to the fmu. According to the picture I showed in your other thread, fuel goes in at the port underneath the bleeder valve, fuel goes out at the opposite side. Fuel in comes from the fpr, fuel out goes to the fuel tank. And just to be sure, the return line back to the tank is identified as the line penetrating the firewall without the fuel filter.

 

Yea that is all correct...
When I was having the original problems with it pulsating and shooting to 100 on the fuel gauge thats when I had it in backwards..there is marking on the bottom of the cartech that I had to flip flop. Its all in there correct now and still problems.
My next thaught is buying a mecanical fuel gauge for 20$ and putting that on the FPR....
This boggles my mind because the Fuel Pressure gauge is gettin power and reading pressure at idle so it should work...possibly a bad sender unit ?? or the cartech is bad ??

-matt

 

Yeah, having a mechanical fuel pressure gauge mounted on the fpr is helpful.

It sounds like your elec. fuel pressure gauge is working. Maybe the Cartech fmu is bad. It would help if you could get ahold of a Vortech nonadjustable fmu with an 8:1 disk in it and put that in place of the Cartech and see if your fuel pressure behaves any better.

 

I dont have a vortch fmu that I know is working...

I was researching the cartech and a rebuild kit for it is only $35...would it smart to go ahead and buy that or will I need an entire Unit...??
I do think that my fuel pressure gauge is working properly, but I dont understand why its not passing a certain psi..could be the cartech >>

what should I do next ?

-matt

 

Rebuild kit is worth a shot, and it's not too expensive.

 

Well what if that doesnt cure it..I just had the top diaphram off of the cartech and that thing doesnt move all that much...Do I buy a new unit ?? or rebuild kit.. ??

-matt

 

It has to be the cartech...the fuel pressure gauge wont go past 48 psi with the set screw in the middle set all the way in...

-matt

 

I refuse to think its the Cartech...Can the sender unit for the Fuel pressure gauge have a dead spot past 48 psi..?? the guage is working but i dont know...I dont think the cartech would just be that dead..I have the pressure on the cartech and no change on the inside of the car

When I installed the fuel pressure gauge, the fp sender lines coming into the car had an extra green wire I left hanging...could that have any bearing on this ?? there were 4 connections on the black box from autometer, and there were 5 lines coming from the sender ??

-matt

 

But the pressure gauge went up over 100 psi when you had the fmu hooked up wrong. So, I think the gauge is probably good, but you can get a pretty cheap mechanical fuel pressure gauge to hook up to your fpr to compare against.

By the way, when you were screwing the center bolt in, did you screw it in a couple of turns and check your fuel pressure, then screw it in some more? Or did you just screw it in all the way and then check the fuel pressure?

 

No I screwed it in a couple turnes then checked then a couple more then checked...then I did it again where I sat in the car and my dad did the cartech part...the highest it went was 48 and that was really early on in the screwing in

I cant understand how the cartech can just NOT work, thats why I kinda think its the sender?? I dont get it...could the diaphram be ripped/damaged...

-matt

 

10 characters..

-matt

 

And you're sure the mityvac stayed at 10 psi the whole time?

 

yes..i made sure of that...I checked throughout the test and at the end when the screw was ALL the way in, that the PSI was stil at 10...definetly was

I took my boost guage off of vaccum pressure and Ted that with my cartech and the mityvac and used the boost gauge as my reference point..SO the catech is gettin Boost pressure but not reacting AT ALL to it. just to 48..thats is

-matt

 

Okay, I hope I'm not offending you with all these questions, I kind of feel like the computer service guy who asks are you sure your computer is plugged in. Gotta make sure, though.

Do you know what model of Cartech fmu you have? Some models are for NA cars and don't react to boost pressure the way that the boosted versions do.

 

No its cool...Im glad your sticking with me on this because you know more, Alot more than I do about this...even with all my knowledge and my father, I cant seem to get this to work...its boggleing my mind...big time

You know what..I have no idea what version I have...the kid before me boosted fine with this same cartech somehow (Seximagtr) he has a turbo on his max now...I figured this cartech would work figuring he used it...

I looked on the website and the modle I thought it was, is 2025...I see where your saying that there is an N/A application one but i figured this is for the boosted applications

-matt

 

Well the fuel pressure gauge is working..I went for an easy ride with the car and I gave it gas to about 3000-3500 and i got about 48-50 psi of fuel pressure...I didnt boost though do I dont know..I PMed seximagtr, to see if he knows the modle number...i dont know how he ran it with with the s/c witrh no problems....maybe im missing something

-matt

 

I found it..I took the cartech apart and it needs a rebuild kit...theres a metal aluminum peice in there thats fairly well bent...

I called cartech and spoke to a really nice guy Tray Herman. $35.00 later and I have a rebuild kit on the way. He took me through the breakdown of the unit and what will be replaced...good deal..he explained to me this happens alot to used units and replacing these parts will bring my unit up to new..

-matt

 

hey im glad u figured it out. i got some questions, when you screw the center screw all the way down. what setting are you at? and on the average where should be set? and on the ratio adjustment **** how many turns in what direction to a 10:1 ratio?

 

Im still waiting for the rebuild kit so I really dont know if this worked 100% yet...hopefully It will be here tomorrow and Ill have this thing in and driveable

If not, Ill make another Post

-matt