New Engine won't lean out

Smaller injectors...egr needs replaced.....advance timing.....

I'm running 42# injectors on my motor with no problems (302 with stock ported heads) and have no problems at idle. I also got my car tuned at a performance shop so I can't really help you out. I doubt its the injectors being the computer can regulate how much fuel enters the motor.

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.

Blk91stang said:

I'm running 42# injectors on my motor with no problems (302 with stock ported heads) and have no problems at idle. I also got my car tuned at a performance shop so I can't really help you out. I doubt its the injectors being the computer can regulate how much fuel enters the motor.

Click to expand...

It's BECAUSE of your custom tune that you're having no problems. The EEC alone would not allow your car to run well at all without that chip. If you're unsure that that's true... pull the chip and go for a drive. lol IIRC, the stock EEC is only able to make variations to a maximum of 20% in either direction. 36 lb injectors are WAY outside of the EEC ability to adapt consdiering it's expectation of 19 lb injectors.

To the original poster:
In other words: You need a custom tune whether it be a chip burned by a dyno shop or a user programmable unit like TwEECer or the Anderson PMS (both popular with our cars).

The engine might be running rich, but what do the oxygen sensors say? If your not burning well in one or more cylinders, it will be sending now only raw unburnt fuel down the exaust, but also oxygen that should have been used to burn that fuel. So, you'll smell raw fuel, and the computer will smell raw air and will conpensate with more fuel until it hits it limits of adjustment. Also, check the MAF readings. MAF out of range is another problem.

Daggar said:

the stock EEC is only able to make variations to a maximum of 20% in either direction. 36 lb injectors are WAY outside of the EEC ability to adapt consdiering it's expectation of 19 lb injectors.

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Not to hijack but just for my own knowledge, does this place 30lb injectors within the spectrum of the computer's ability to adapt?

I've seen a good handful of folks get away with 30's on the stock EEC with little or no trouble. Maybe just a little rich at idle while others had no success whatsover with injectors over 24 lb. A lot of that could have to do with things such the condition of the rest of ther tune and sensors. Without having a wideband in the car or some way to tell what the motor is doing, it's difficult to say what will work for who. Some things can be made up for with fuel pressure adjustments. But if you're pig rich down low and lean up top, there's no way to adjust for that with just fuel pressure.

Daggar said:

It's BECAUSE of your custom tune that you're having no problems. The EEC alone would not allow your car to run well at all without that chip. If you're unsure that that's true... pull the chip and go for a drive. lol IIRC, the stock EEC is only able to make variations to a maximum of 20% in either direction. 36 lb injectors are WAY outside of the EEC ability to adapt consdiering it's expectation of 19 lb injectors.

To the original poster:
In other words: You need a custom tune whether it be a chip burned by a dyno shop or a user programmable unit like TwEECer or the Anderson PMS (both popular with our cars).

Click to expand...

SORRY TO BURST YOUR BUBBLE!! But right after I finished putting the car together, I took the car for a drive, started perfect, idled perfect, even ran to 3/4 throttle GREAT! Didn't attempt full throttle cause didn't know the a/f ratio. Car ended up making 374rwhp untuned WITHOUT a chip (was pig rich on top because of my 12:1 FMU)

Next time you lecture about the EEC in our cars, include my post to PROVE what really happens using some "real world testing" because despite everything you said, my car ran better than stock.

I understand some cars may be different and have different combinations, but remember to include what you said doesn't apply to everyone. In this case 86Bandit might indeed need a custom tune to fix his problem whereas I didn't.

Your sig and your post says 42# injectors... So now you're telling me that you ran 42 lb injectors and a 12:1 FMU with the stock EEC (if that's the case then you truly know nothing about tuning) and it started up and ran fine???? I don't think so Tim.

As for real world testing... I'll stack amy resume against yours any day.

86bandit said:

Just dropped in a injected 351 (spider intake, 36 inj, C&L 73 MAF) into my 87 coupe (converted to mass air previously). The fuel system is a 255 Walbro with Aeromotive regulator and Edelbrock rails. My problem is that no matter what fuel pressure I run it idles consistently rich. TPS is set at .93VDC and at idle I'm seeing about .9-1.0 VDC at the air meter. Timuing is set at 10 BTDC. Any suggestions would be helpful.

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why only 10 degrees of timing? i know i will be comparinging apples to oranges here but every 351w tech article i have read (thing is they usally have a carb on them) is running 18 degrees intial timing. thats what i run i have a carb however not a computer going what the heck is going on. 38 degress total timing on mine no vacuum advance.

Daggar said:

Your sig and your post says 42# injectors... So now you're telling me that you ran 42 lb injectors and a 12:1 FMU with the stock EEC (if that's the case then you truly know nothing about tuning) and it started up and ran fine???? I don't think so Tim.

As for real world testing... I'll stack amy resume against yours any day.

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1) Yeah, this was BEFORE tuning.
2) I question why you ask about the 12:1 FMU as this plays NO role in startup and running, only under boost does the FMU restrict the return line to increase fuel pressure.
3) My name is Matt, not Tim.
4) Your correct, I don't know much about tuning. If I did I wouldn't have paid $700 to get my car properly setup. I wish I had your knowledge .
5) Obviously your resume doesn't include driving a mild 302 with 42# injectors everyday so I think I'm in good shape here.

Daggar said:

It's BECAUSE of your custom tune that you're having no problems. The EEC alone would not allow your car to run well at all without that chip. If you're unsure that that's true... pull the chip and go for a drive. lol IIRC, the stock EEC is only able to make variations to a maximum of 20% in either direction. 36 lb injectors are WAY outside of the EEC ability to adapt consdiering it's expectation of 19 lb injectors.

Click to expand...

Pulled the chip, car still runs good. I think you need more knowledge about these cars before criticizing others. I only stated the injectors did not give me a problem and your panties got all in a twist.

Sorry for the hi-jack, as my opinion has already been stated.. just backing it up....again..

need to drop to 24lb injectors and raise timming to 14

Blk91stang said:

1) Yeah, this was BEFORE tuning.
2) I question why you ask about the 12:1 FMU as this plays NO role in startup and running, only under boost does the FMU restrict the return line to increase fuel pressure.
3) My name is Matt, not Tim.
4) Your correct, I don't know much about tuning. If I did I wouldn't have paid $700 to get my car properly setup. I wish I had your knowledge .
5) Obviously your resume doesn't include driving a mild 302 with 42# injectors everyday so I think I'm in good shape here.



Pulled the chip, car still runs good. I think you need more knowledge about these cars before criticizing others. I only stated the injectors did not give me a problem and your panties got all in a twist.

Sorry for the hi-jack, as my opinion has already been stated.. just backing it up....again..

Click to expand...

...and I think you should gain at least some clue of subject you're talking about before giving advise that is potentially harmful.

Being able to start a car and have it idle does not indicate that it runs correctly.

Running a 12:1 ratio FMU with 42lb injectors is insane, yet your post would have one believe that this is ok.

Very well, "I don't think so Matt."

If you know nothing about tuning then why would you even consider offering advise on the subject? The 20% that I mentioned above (+/- %5) is an actuality. Not something pulled out of the air. There are several things regarding the electronic tuning of an EEC IV that need to be considered when swapping out injectors including but no limited to: Battery Voltage vs. Injector Breakpoint, Injector offset, Open vs. closed loop Pulsewidth, Cranking pulswidth, and high and low injector slopes for the size injector being used. The adaptive control in an EEC IV is very limited in what it can do on it's own. Just starting a car and idling with a set of 42 lb injectors can put you BEYOND the adaptive control's ability to trim fuel (it's outside the before mentioned 20%). As RPM and injector demand rise, so do the differences between amount of fuel that the EEC "thinks" it's sending and the amount of fuel that is actually being delivered. The Mustang EECIV was programmed with fuel tables specifically designed to run a 19 lb injector (with the exception of the 93Cobra). The reason that that is significant is let's say for instance:

At full load and 3/4 throttle, the EEC tells the injector to pulse 10 times for each and every stroke. Now remove the 19s and install a significantly larger injector in it's place. The EEC doesn't know the difference so it pulses the same and dump a LOT more fuel than it's aware of.

Take the same scenario at 4600 RPM and assume the pulsewidths is twice that. The differences between the two injectors in volume of fuel delivered has increased even more! Maybe at 2300 we delivered twice as much fuel... but at 4600... now we're dumping 4 times that fuel or even more depending on what the differences are between the those two injectors. In this case we're talking about a difference of around 202% in the amount of fuel a 42lb injector is capable of delivering when compared to a 19.

Having a meter calibrated do coincide with a fuel injector is a neat trick! It works great in a great many circumstances. Unfortunately it won't compensate for injectors that are 36, 42, or larger without additional tuning. The differences in the scalers that I mention above grow wider and wider the further up the RPM that you go.

Most of your attempt at post bashing so far has been pretty senseless. If your car ran so great, why the $700 for a tune? You must have just had it burning a hole in your pocket. And you're right, if you knew what it took to tune, you'd likely not have had to spend that kind of dough to make it run correctly although I've got no gripes about custom chips whatsoever. It's the right way to tune EEC fuel injection along with some of the many user programmable units that are available (some of which I mentioned above).

You're apparently under the false impression that you're the first person to run 42s in a 302. LOL Good call. Go back and reread the entire thread, do a little homework, then come back and tell me what part of my posts were incorrect.

Here's a good place for you to start:
http://fordfuelinjection.com/files/EECIV_Inner_Workings.pdf

It's apparent that you took my first post as an attack instead of an effort to give some clarity to the original poster. Regardless, it's still correct.

I respect the vast amount of knowledge you have about these motors but my post had nothing to do with that. I was simply replying on your post (which I attached at the bottom) which clearly stated my car wouldn't run correctly and should run noticably bad without a chip which was completely FALSE. All I said...

Let me restate, I ran 42# injectors along with a 12:1 BEFORE my tune. The car ran great, made 373rwhp on the dyno, ran real rich but no harm came of it. I purchased a chip and tune to get rid of my FMU along with making sure everything else was good. I picked up 30rwhp because of it. $700 is pocket change compared to the amount I already spent on the car in order to not grenade the shortblock (which turned out was not a problem anyways).

Daggar said:

It's BECAUSE of your custom tune that you're having no problems. The EEC alone would not allow your car to run well at all without that chip. If you're unsure that that's true... pull the chip and go for a drive. lol IIRC, the stock EEC is only able to make variations to a maximum of 20% in either direction. 36 lb injectors are WAY outside of the EEC ability to adapt consdiering it's expectation of 19 lb injectors.

To the original poster:
In other words: You need a custom tune whether it be a chip burned by a dyno shop or a user programmable unit like TwEECer or the Anderson PMS (both popular with our cars).

Click to expand...

Very well, we'll agree to disagree. You and I define running "correctly" differently, I suppose.