elio3848

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I have a 1995 mustang gt automatic with a built engine, it has a 331 stroker kit, stage 2 trick flow top end kit that comes with the trick flow stage 2 camshaft and full exhaust with x pipe high flow mufflers and around 10.5/1 compression. I just bought this car and the past owner gave me 2 SCT tuning chips saying that all I need to do is take my car to a dyno shop and get it tuned. Well, the car has been at a "professional dyno tuning shop" for the past week and I recently received an email saying he can't get the car to run leaner he said the car is too rich and doesn't know why.

Any advice?!?!?!?!?
 
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stanglx2002

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What size injectors?
Is the MAF calibrated fro the above injectors size?
 

96pushrod

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Sounds like you need a new tuner.
You could get a quarterhorse setup and learn tuning yourself, or step up and go with a megasquirt based setup. I’d choose option 2 as there are more people versed in tunerstudios than binary editor/tuner pro
 
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elio3848

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Sounds like you need a new tuner.
You could get a quarterhorse setup and learn tuning yourself, or step up and go with a megasquirt based setup. I’d choose option 2 as there are more people versed in tunerstudios than binary editor/tuner pro


supposedly the tuner told me that the sct chip he flashed is already set up good and the tune on the computer is compatible with the build but there is something wrong with the wiring harness or the computer from the factory itself is bad
 

elio3848

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Well, not to knock the person trying to figure out your issue, but have you considered finding someone who knows EEC-IV Mustangs?

Whenever you take a car that far, part of tuning is going to involve re-engineering the entire system to function cohesively, not just adjusting parameters in the computer. You may need someone more familiar with modding 5.0s.

what would need to be changed entirely?
 

96pushrod

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HiTech Motors out of Elk River MN
I looked these guys up, their track record for tuning isn’t good, especially if you get into fb reviews.

If maf and injectors are functioning properly, a half competent tuner should be able to dial in fuel - especially on a dyno. You’re better off getting a remote tune done over Dealing with somebody who doesn’t know what they’re doing.
What did he say your a/f was at?
 

elio3848

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I looked these guys up, their track record for tuning isn’t good, especially if you get into fb reviews.

If maf and injectors are functioning properly, a half competent tuner should be able to dial in fuel - especially on a dyno. You’re better off getting a remote tune done over Dealing with somebody who doesn’t know what they’re doing.
What did he say your a/f was at?

at idle i was told 10.8/1 after he "commanded" 25/1 in the tune because the car was running so rich
 
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96pushrod

I think they're a little easier to get off
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at idle i was told 10.8/1 after he "commanded" 25/1 in the tune because the car was running so rich
If he’s using commanded fuel to dial in Actual fuel then he is a terrible tuner.
Get your money back and hit up Willie at dirtydirtyracing. He does remote tuning.
 

96pushrod

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im gonna try to figure most of this out on my own so what should he have done?
Injector slopes and maf curve are used together to dial in air fuel. There are great guides online for how to tune these systems.
 
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elio3848

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Terribly sorry for the delay in response. I didn't know you had replied.

That's a complicated question. As Mustang5L5 said, we need more info, but trying to tune over a forum really isn't ideal. Finding someone who can go through your system to make sure it's solid before tuning is critical. As an example, making sure all the right components are there and functioning properly before getting started. Then making sure the appropriate computer control components have been replaced such as MAF, injectors, and fuel pressure regulator. Both the condition of the base system and the compatibility of the modified components can mess up the ability to tune the computer. Then the tuning begins. However, all of that assumes that the components in the engine are really what you were told were in there, are all installed correctly (such as the cam being dialed in right) and complimentary — although, if they really are all TFS Stage 2 parts they should be.

If your mechanical combination is everything you've shared, it doesn't sound like anything too terribly wild. The compression is a bit high, but as long as it doesn't detonate, it shouldn't matter. In fact, from what I know, it should run with just the right matched MAF and injectors — it would probably benefit from being tuned incorrectly, though — but I don't have a specific MAF/injector combo to recommend. I would find someone who can work with you to dial in your combo from mechanicals to fuel and ignition system, to computer tune.

Modifying any car really is in the realm of engineering, not auto repair, which means a need to approach it from a different mindset than a parts replacement mentality, so having someone who can do that is more critical than any specific parts recommendation — unless someone has a completely engineered system that works.

Were I in your shoes, I'd be looking for tuners with excellent reputations who have specific expertise with building and tuning naturally aspirated EEC-IV 5.0s — '94-'95 experience is probably helpful if not critical, as well.
I would need to know more specifics of your combo. For example what MAF brand and injector size are in the car?


Sorry for the late response,
I recently put in 30 lb injectors in and sent my MAFback to PRO M to be recalibrated as it was previously calibrated for 42#, but the troubling part is it still runs like sh*t. Weirdly enough I am able to keep the car running (blowing plumes of white smoke) when I disconnected the MAF and take off the filter (I'm running a MAF where it is mounted on the filter), and when my air filter and MAF are installed the car won't even fire when turned over, I'm thinking that it's running so rich that the little amount of air restriction the filter provides is the choking the engine off totally.

I am now looking into to see if I have ECM damage because I get the code 511 (Read-only Memory) from when I put my diagnostic scanner on it.
 

jozsefsz

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Sorry but the reply above is not correct in any respect. A 511 is a standard error code when you have a piggy-back chip installed. Your computer is not toast.
If you've had your MAF calibrated to your injectors, you need to remove your piggy-back chip with the questionable tune on it. Otherwise, the tune needs to be corrected to the new MAF curve. If you have a 511 after removing the chip, then you may have a problem.

The plumes of white smoke are most likely an extremely rich condition, likely nothing to do with the head gasket. That's a common failure, but as you mention it's running pig-rich, that's just raw fuel coming out of the tail-pipe. Especially if it smells like raw fuel and makes your eyes water.

Step 1 - remove piggy-back chip if you haven't already and give things a try.

Step 2 - you may have a stuck-open fuel injector. your tuner may have been oblivious to this (they often aren't good with mechanical problems). check your fuel pressure. if it goes to zero quickly after shutting off the car, you may have one that is stuck and is dumping all of the fuel into a single piston (leaving other cylinders lean and barely running). Your symptoms are identical to mine when I had that happen. This type of mechanical failure cannot be corrected with a tune. If you are running 'Bosch Green Giants' especially if sourced from eBay, be very very skeptical and assume this is your problem.

- If you suspect this is true based on fuel injector brand and / or fuel pressure readings, replace injectors with a good set.
- Change your oil because it's now filled with fuel and will wreck your engine.

Step 3 - if you have verifiably corrected the fuel injector situation in step 2 (don't try and skip that step), installing an adjustable fuel pressure regulator gives you some level of control over fueling. My calibrated Pro-M was calibrated too rich by the factory. Turning down fuel pressure a pound or two allowed the computer to get into the range where it could comfortably adjust fueling.
 
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elio3848

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Sorry but the reply above is not correct in any respect. A 511 is a standard error code when you have a piggy-back chip installed. Your computer is not toast.
If you've had your MAF calibrated to your injectors, you need to remove your piggy-back chip with the questionable tune on it. Otherwise, the tune needs to be corrected to the new MAF curve. If you have a 511 after removing the chip, then you may have a problem.

The plumes of white smoke are most likely an extremely rich condition, likely nothing to do with the head gasket. That's a common failure, but as you mention it's running pig-rich, that's just raw fuel coming out of the tail-pipe. Especially if it smells like raw fuel and makes your eyes water.

Step 1 - remove piggy-back chip if you haven't already and give things a try.

Step 2 - you may have a stuck-open fuel injector. your tuner may have been oblivious to this (they often aren't good with mechanical problems). check your fuel pressure. if it goes to zero quickly after shutting off the car, you may have one that is stuck and is dumping all of the fuel into a single piston (leaving other cylinders lean and barely running). Your symptoms are identical to mine when I had that happen. This type of mechanical failure cannot be corrected with a tune. If you are running 'Bosch Green Giants' especially if sourced from eBay, be very very skeptical and assume this is your problem.

- If you suspect this is true based on fuel injector brand and / or fuel pressure readings, replace injectors with a good set.
- Change your oil because it's now filled with fuel and will wreck your engine.

Step 3 - if you have verifiably corrected the fuel injector situation in step 2 (don't try and skip that step), installing an adjustable fuel pressure regulator gives you some level of control over fueling. My calibrated Pro-M was calibrated too rich by the factory. Turning down fuel pressure a pound or two allowed the computer to get into the range where it could comfortably adjust fueling.

When I remove the chip I just get the codes stating the car is running rich lol. The ecm isn’t damaged the car is running exactly how it should be with a stock ecm and big cam.

I have recently replaced the injectors (upgraded from 19# to 30#) and the car runs a little better but still super rich. Plus the car holds fuel pressure.

The car already came with a adjuster fuel pressure regulated and I set it to 37-40 psi.
 

jozsefsz

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"Turning down fuel pressure a pound or two allowed the computer to get into the range where it could comfortably adjust fueling." That's what I'd do next.