Well, I received my mid-america fuel pressure gauge and hose today.
I hooked it up and on the way to work at about 5000 rpm I had 60 psi and then I'd hit the rev limit or whatever is going on and the car and fuel pressure would take a nose dive.
I had the FMU one turn ccw from full cw position.
I tried it all the way cw and made a run in second gear and this time it went to 80 psi fuel pressure but again the fuel pressure took a nose dive to below 30 psi at least when the car went flat at about 5000 RPM.

Anyone out there have any ideas on what's going on?
Thanks
Herb

 

I don't understand why you just don't take it to the place that installed it. They are obligated to make it work...

 

Are you losing fuel pressure in parallel with the engine RPM's? Or are the engine RPM's staying high while pressure is dropping?

If you are losing fuel pressure while the engine is at 5000k and under boost, I'm afraid you're really gonna hurt your engine and lean it out, if you haven't already. I wouldn't drive it. It could be that your stock injectors are locking up under such high fuel pressure (80psi) From what I've been told is that pintle style injectors have a tendancy to lock up at anything over 60psi. You can call www.tpis.com and get their opinion.

I know you don't wanna hear this, and simply throwing money at a problem isn't always the best solution. HOWEVER, I would really recommend you upgrade your fuel system.

www.racetronix.com

Get the GSS340 255lph pump with harness. It takes about 1 hour to install and allows you to remove the POS aux pump that comes in the kit.

Also, go to summit and buy some Ford Motor Sports (FMS) injectors. At least 30lbs.

Then send your chip out to fellow forum member Jesse (aka ski_dwn_it) www.azzatochips.com

Also, you're gonna need some kind of AFPR (Adjustable Fuel Pressure Regulator) I use the $125 Aeromotive LT1 unit.

All of this combined will run you about $775. OUCH! I know, but I'm telling you it's necessary. Then you can ditch your fmu, or simply use it to do minor tuning if necessary. Running 60psi of fuel is the wrong way to overcompensate for boost.

You should NEVER see as low as 30psi of fuel, even at idle. How much max boost are you seeing during this condition?

Have you changed your fuel filter. I know that's probably not the problem, but a good idea anyway.

 

Both RPM and Fuel pressure goes down together.
The ATI manual says it should idle at 40 psi and the injectors will lock up at 95 psi. I'm only getting to 80 psi.
I've been talking to Mike at superchargers4less and he thinks it may be plug wires.
Since I have 52000 mi it won't hurt so I just ordered a set of accel wires from Mid-America.
Yes, I changed the fuel filter.
Later
Herb

 

Unless you live next door to Mid America, these parts must be costing a fortune! There are much,much cheaper places to buy performance parts.

 

That's certainly not what I've heard. They can lock up below 95. Did you call TPIS yet?

It's a good idea to change them don't get me wrong, but your FP shouldn't be dropping to 30psi. That makes me think something else is wrong.

To rule out any ignition problems:

Did you intall new colder plugs and gap them to .035"

You should also throw an MSD with timing retard on there too.

 

So let me get this straight?

When you punch it out of the whole your RPM starts climbing and Fuel climbs to 60-80 psi then around 5,000rpm it drops to 30? What year of car is this and you dont have a fuel shut down switch or anything do you?

I install NOS kits and one time this guys fuel dropped (bad pump on it last leg) and it shut down the car BUT the NOS was still on! almost blew it apart..

Also are you hitting the rev limiter or anything...

If you have the time call Jason Esher...he worked for procharger for i think 11 years and he knows prochargers/superchargers like the back of his hand i am sure he has seen this problem before!!!

Jason Esher PH. 303-670-5011

http://www.automotionperformance.com/contact.html

 

Yeah, it acts like I'm hitting my rev limit but it's too early.
What happens is the car just falls flat and when it does the fuel pressure drops.
I talked to ATI and they think it might be the injectors.
They said the stock Vet has a disk type and sometimes they lock up early.
He said the stock replacement Bosch are a different type or I could get some at Ford for the Mustang. They said it was the same kind the Vet uses.
I've got an appointment to put it on a dyno Thursday and see what the A/F ratio is and go from there.
Thanks for the phone number. I'm calling him as soon as tomorrow.

P.S Kevin, I just got off the phone with Jason. Very nice and helpful guy.
He knew who you were as soon as I told him your user name. Thanks
Herb

 

If you need injectors, give this place a try, they have great products and excellent service. precision turbo and engine.

 

When injecters lock up do they lock open or shut?....if shut that wouldn't explain the lose of fuel pressure....at what pressure does that fuel pump vibration isolater....lose pressure? its just a force fit...sounds like a rev limiter kicking in.....you should be able to get 60 lbs without any injecter problems. I ran my 24 lbs injectors for two years at 60 lbs.

 

Herb..

Did jason give any good advice i thought forsure he has run across this problem before?

 

Funny how ATI says one things, then you call 'em and they say another. Let this be your first lesson to take everything they say with a grain of salt. HECK, they even told me TWICE they dont' sell 8 rib pullies for the P1-SC, guess where I ended up buying mine from ... ATI!!! The tech's have little to no experience.

Anywhoo...

The stock Lucas/vette injectors are pintle style just like the FMS (bosch) injectors are. However, Ford rates their injectors at a higher psi, so 24 stock are lower fuel rate than 24 FMS injectors.

The right way to do this is to have your ECM reprog'd and go with higher psi injectors. At least 28's or 30's. There's nothing wrong with going even higher too if you intend on eventually having more HP in the future.

I'm running 30# FMS injectors, and my car runs great with a ski_dwn_it (azzato) chip with 45psi of fuel @ 8psi of boost at 5800RPM.

Once I get my wideband and If I need more fuel, I have overhead on my injectors to up the psi to get the desired AF ratio.