Flfinn

Just finished 305TPI/T5 -> 355TPI/T5 swap and and she woke up nicley, BUT: running rich!

Fuel pressure is set at 39 PSI (could'n get lower..) and injector on time's are set as low as possible!

Air/fuel ratio meter shows rich all the way at idle speeds. TPS is set at 0.54v. Maybe the injectors are too big.. estimated output on the motor is about 300-350 hp.. The 22's might not be enough..?

Mods are:
LT4 Hot Cam,
Accel, ported 2" siamised runners,
ported stock intake,
ported, siamised plenum,
homemade 52MM TB,
30 lbs/h Ford SVO's (too big??),
Haltech ECU,
ported stock iron heads,
multiangle valvejob,
modified&polished Manley street E/race I flow valves,
Silv'o'lite KB 106 .030" over pistons (CR 10.5:1),
Cranecams valvesprings,
airfoil,
Edelbrock TES,
Dynomax 3" cat back,
no cat, air..,
K&N,
etc.

cp87GTA

You may have too much injector. I'm only running 24 svo's and I'm a little rich at idle. And I'm burning my own chips. With the stock chip it's real rich. I've tried both a 305 and a 350 stock chip too.

Rob P

iTrader: (1)

My 24lb SVO's cause my ZZ4TP to run rich. I'd say too much injector without a chip modification.

Grim Reaper

If you HAVEN'T altered the eprom to let the ECM know that you have larger injectors - THAT'S YOUR PROBLEM!

You don't mention whether you have SD or MAF, but it's really irrelevant since a change of injector size MUST be adjusted in the eprom to make the engine run right. Also, generally the Idle speed needs to be played with when you get a "decent" cam plus a host of other "little things" that affect overall driveabiitily.

DEFINITELY get into burning your own eproms. The cost of the equipment is about the same as a reasonably priced "custom eprom". And then you can "tune it" further to make it exceed ANYTHING any "custom eprom writer" can do by "specs".

There is NO WAY any custom eprom writer can write an "optimal" eprom WITHOUT "hands-on" access to your car. And that costs BIG BUCKS.

Go to the DIY Prom Board, and read the VERY FIRST POST (Announcement) regarding Traxion's Prom Burning Introduction. Then start reading some of the older posts. All the information you need is there.

Flfinn

It's a SD. I don't have to burn any proms, thanks to HALTECH ECU. Haltech allows me to tune everything needed by pc. As I wrote, the injector on times are set as low as possible, but that's just not enough. And propably that's because of too big injectors, but maybe not?

And yes I understand that the compures has to know that there is bigger injectors on the game now..

Grim Reaper

Adjusting by Fuel Pressure is NOT the way to compensate for fuel if that's how you are doing it. In fact, when you have control of the ECM, you run a "constant" fuel pressure where the pressure is high enough to promote good atomization yet not so high as to burn out the fuel pump. I find 46-48 psi is a good range.

Can't you just change the "Injector Constant" with that fancy Haltech? If not, sell it and go back to the SD 7730 because it isn't able to do what we can do with the SD 7730.

Flfinn

I understood that the f*rd SVO's are designed to work in a lower fuel pressures, like 36 psi. But maybe I'm wrong. That's why I tried to lower the pressure.

getting a litte off topic:
Haltech is a map based system. Injector firing times are set as mS's and ign advance as degrees. The computer also uses engine speed and load, temperature etc. to acces the base fuel map. There is 22 fuel ranges, every 500rpm to 10500rpm and 32 load points per range, up to 16mS with 0.016mS resolution. www.haltech.com

does 'injector constant' means something similar to that?

Matt87GTA

No kidding Glenn!

If there is no way to accurately communicate the size of injector you are running to the ECM with the Haltech, that is some kind of a joke for a system they are selling....

But if you have whatever settings available to you for putting less fuel into the engine, and it continues to run rich, you likely do have too big of an injector (for what you are running). But really, you can just about make any (reasonable limits) injector work with any application if it is 'too large' on both the 165 and 730 ECMs.

I have 30lb SVOs in my 355 with the LT4 HC running a 165 and I was able to tweak my injector constants (as well as a bunch of other stuff) and get the car to run excellent with them. It is taking a bit more to get all of the little things in line, but the car is perfectly driveable at this point (especially as far as the injector size goes).

Flfinn

Matt, you have those nice heads and I have crappy ironheads. That could have some affect to the issue. Where's your FP set at?

With haltech I am not yet experienced enough to say everything is adjusted ok. My friend has a 383TPI, 38lbs/h injectors, Edelbr. heads, base, slp runners, crappy 2032 crane cam, etc., and haltech with no problems.. if some traction problems don't count

Matt87GTA

My rail pressure is set to 47psi right now.

You may want to call Haltech and ask them what procedure they recommend for setting the system for a particular injector size (ie. what parameters need changing and in which direction).

The material that the heads are made of will not effect the fuel needs of the engine. It will change how much timing the engine likes though.

Grim Reaper

I agree. I CANNOT believe that Haltech would make a system that wouldn't allow you to change a "simple variable" for different sized injectors.

Also, have you tried the DFI/ECM Board? I think there are a few Haltech users there. They might be able to give you a "quick answer".

Flfinn

I made a few calls (to haltech dealer and a few haltech owners) and it seems that there is something else wrong than the injectors.

As I set the injector firing times to zero the engine shouldn't be running any more. The engine run worse before i changed the injector times, so it made a difference.

--> all that fuel is getting there somehow..
maybe coldstart injector is leaking.. can't think of anything else!

Matt87GTA

Ahh... that makes sense now (the Haltech).

Not sure what the problem could be.... With the new injectors that presumably don't leak, it really shouldn't be getting enough fuel to actually run no matter what else leaks. I mean, I wouldn't think the engine would run with a little fuel coming from just the CS injector or a blown fuel pressure regulator.... maybe pop a bit here and there, but not actually run... hmmm.....

Flfinn

I will disable the CS injector and see if that helps. If not, next i check FP regulator. But not until next week when i have the time.

If the FP is blown shouldn't there be fuel coming out of the vacuum nipple where it connects to the plenum? I have a FP gauge and it shows ~50psi when i disconnect the FP vacuum line.

At first i had to keep it running. It ran really rich - O2 signal was ~890mV at idle. wouldn't rev past 3000rpm.