Vehicle ran rich, now i know why

Gravy · 10-16-2007

Ok, need a quick, best guess by a few people on here.

Car normally comes with 360cc injectors, and recently, i decided to pick up a set of DSM 450 injectors. Well, today out of boredom, i pulled the part number on the injectors and found the following number: D1151BA

Google tells me they are 550 injectors, this explains my plugs being soot coated and having WAY too much water(smells like gas) coming from the exhaust with lots of black goodness. Going to be looking tomorrow, but about what should i be running the injectors % wise on the SAFC-II?

Going to bed, but i figure with all the minds on here, someone should be able to help me with this. Stock(oem) fuel pump at the moment and no FPR. Too late to do math right now.

**JET** · 10-16-2007

What color are the tops of the injectors?

Matt D. · 10-16-2007

Quote:

Originally Posted by Gravy

Google tells me they are 550 injectors, this explains my plugs being soot coated and having WAY too much water(smells like gas) coming from the exhaust with lots of black goodness.

Water coming from the exhaust? No way! Last I heard is that when a hydrocarbon burns it creates CO2 and H2O.

Gravy · 10-16-2007

Quote:

Originally Posted by Matt D.

Water coming from the exhaust? No way! Last I heard is that when a hydrocarbon burns it creates CO2 and H2O.

NO WAY!!! Get outa town. I had it parked by the wall, with the exhaust a good 6-8 inches away, and after 2 minutes of idle, i had 2 one foot patches of black on the wall, and a pudle of water on the ground which looked and smelled like there was a bit of gas in it.

The tops are black, and i know hey arn' stock. I've tried toying with the fuel mixture + or - a few %, and after only 200 miles on the plugs, they're already fouled.

Matt D. · 10-16-2007

Quote:

Originally Posted by Gravy

NO WAY!!! Get outa town. I had it parked by the wall, with the exhaust a good 6-8 inches away, and after 2 minutes of idle, i had 2 one foot patches of black on the wall, and a pudle of water on the ground which looked and smelled like there was a bit of gas in it.

The water will smell like gas, after all that is where it comes from. You need to get your hands on some proper tools and give up on the visual cues.

**Shane@DBPerformance** · 10-16-2007

Take the injector size the factory ECU is set for, divide that by the new injector size and then subtract 1 from it. That will give a general starting point for you.

(360cc/550cc) - 1 = -34%

You have to be extremely careful on the 3s cars though with bigger than stock fuel injector and a piggyback systems that try to fool the stock ECU like an SAFC. The 3s cars run way too much timing in the upper RPMs, so you can run in trouble if you try to crank the boost up a lot or if you put in bigger fuel injectors, since going negative with a system like an SAFC has the unwanted side effect of making cars run even higher ignition timing. I wouldn't run 550s on a 3s without a system that can control/retard ignition timing like an AEM EMS or MAFT Pro. Since your car is 1991, you can retard the timing using the CAS, but that will make the timing too low in the lower boost RPMs and at cruising RPMs hurting power and gas mileage.

Gravy · 10-16-2007

Just got the car, and figuring things out. The kid i got it from got it modified, and did a few things himself. I'm just figuring out what it's got done, and doing a few things to get it up to par.

The visual clues are all i have right now, i'm getting a wide band and other mods in the future.