Fastbird93

Ok, after speaking with Jay Fisher, he's recommended I get a new fuel pressure regulator. Reason being, I'm only getting 40 PSI at idle, 46 PSI with the vacuum line off, and when driving, I get a drop in pressure, which I'm informed is NOT correct. So.....

I'm looking at the Aeromotive or the Metco kit. I've heard the Aeromotive takes AN fittings, is this true?? How reliable and proven is the metco kit??

I did a search, but am not coming up with what I want.

QCKZ28

i drop in pressure is usually caused by a bad fuel pump.

jesse

QCKZ28

a bad fuel pump (losing fuel pressure) would also cause a lean condition up top
i also had that problem. my setup is almost idenitical to yours......
a WALBRO 255 fixed my lean problem.
are you also on stock injectors?

jesse

Fastbird93

I'm on 30# svo injectors, and my car is loading up on fuel at idle, not going lean. As the vacuum decreases, map goes up, fuel pressure should go up too as was explained to my by Jay. He explained he's run across bad regulators from the NJ/CA gas additives, which the car is an original CA car now in NJ, go figure. He said the additives eat up the rubber in the fuel system, and the car is 11 years old now. What happens is vapors can get by the regulator and make their way into the manifold, which is definitely going on in my car as I took my TB off one day and got hit with a face full of fuel gasses.

QCKZ28

have you checked the fuel pressure with the vacuum line off, and WOT in 2nd gear until red line?
if it drops your fuel pump is bad.

AdamZ1LE28

I put the Aeromotive Regulator in my car and was very pleased with it. The install was easy....One bolt holds it to the fuel rail, and another fuel line acts as a secondary reinforcement to keep it in place. I did the whole project in about an hour and a half, which included removing the fuel rails, but not disconnecting the fuel line quick disconnects. I love the regulator, it did a lot and was simple to put in.

QCKZ28

what did you set your fuel pressure?

AdamZ1LE28

with the vacuum line on, its right around 52 psi....this sounds high, but i've done a lot of mods to increase air flow, and I'd rather run rich than lean

Fastbird93

Fuel pressure with the vacuum line off is 46 psi, and it's a solid 6 psi gain every time I checked. NOT the specified 10 PSI in the service manual.

When driving, I haven't checked WOT pressure from wherever to redline.

Driving under light accelerating throttle nets me a loss of fuel pressure (should be gain) and then when I go to wide open, it spikes up to about 45-46 PSI. That's the point of hesitation.

I think that Jay Fisher is right with his idea. He says that fuel injectors need a certain amount of fuel pressure to open them all the way, and if they don't have that pressure, then they only open partially and won't completely atomize the fuel. "Pissing" is the term he used. So this "pissed" fuel stream being injected doesn't get burned all the way, loading up the car on fuel. With my 40 PSI and larger squirters, I think he may have me nailed as that's all I can think of at this point. We'll know soon.

I have a Hypertech AFPR on the way (saw too much negative feedback on the aeromotive) as well as a new alternator via Jason Cromer. If I don't get shipped out this weekend, I should have news by monday or Tuesday.

AdamZ1LE28

what kind of bad feedback did you hear about the aeromotive AFPR? I'm very pleased so far.

QCKZ28

check your fuel pressure with the vacuum line off. it should maintain the preset level.

jesse

Fastbird93

Well, I couldn't find what the "preset level" is, but I know this.

When you remove the vacuum line, you should see a 10 PSI fuel pressure increase. I'm only getting 6.

Hypertech AFPR on the way. If I'm still having issues I'm looking at a bad pump aparrently.

QCKZ28

stock fuel pressure for 94-97 is 43.5psi.
i dont know if a 93 is different.
let us know if that fixes the problem.
jesse

pvkn1ght

(not to hijack the thread) but

i've been trying to cure a very slow then high-rev (10-15sec @ 2000rpm) start-up when my car has been sitting in a 10-45min window. when this happens, i usually smell some fuel vapor inside the cabin?!

besides iac/idle, some advise to run a pressure test & replace the fuel pressure regulator. mentioned above, what parts are most damaged from CA gas additives?

my fuel pressure is pretty jumpy (possibly inherent to M6?) and i also get an interesting groan/knock sound coming from the rear, fuel pump?... on right turns. the fuel guage also decreases a noticeably on downhill grades & right turns

sorry so long, any help appreciated thanks, Brian