PCM Tune needed for my 5.8L and A9L

z70what · Jun 9, 2012

Ok guys,
I've gotten my 5.8L running.. the problem is, it runs like crap b/c i have mismatched parts on it.. and i know that's the reason. Anyone on here recommend a good place to get the PCM tuned? Here's what i'm running.

72 351w
MSD Pro Billet Distributor
Trick Flow Upper/Lower Intake 75mm
75mm TB BBK
76mm MAF BBK
Edelbrock Performer RPM Cam
69 Mach 1 heads
24lb injectors
Summit Racing 5.0L Engine harness
Ford A9L Computer

ANyone recommend a good place to get the PCM tuned/flashed? I live in Seneca/Clemson, SC. I know the stock computer is tuned for 65mm tb and 19lb injectors. The engine starts great and idles decent, when it first starts.. but then the computer starts thinking and it idles rough, stumbles, for a few minutes and runs hot ( i know it's b/c of the VERY poor A/F ratio). Any recommendations?

Luke

barronj · Jun 9, 2012

The mustang that your A9 came out of could've just as easily had that cobbled together combination in it & would've run fine. It has zero to do w/ the mfr name on the part- the ECU *WILL* learn the fuel/timing curve needed for your combo.

That combination doesn't require a tune, but putting it in a tuner's hands would pin point your mistake (there is a mistake made, or something's not functioning properly), I would think.

av bronco · Jun 9, 2012

Talk to these guys.
http://eectuning.org/forums/

broncnaz · Jun 9, 2012

barronj said:
The mustang that your A9 came out of could've just as easily had that cobbled together combination in it & would've run fine. It has zero to do w/ the mfr name on the part- the ECU *WILL* learn the fuel/timing curve needed for your combo.

That combination doesn't require a tune, but putting it in a tuner's hands would pin point your mistake (there is a mistake made, or something's not functioning properly), I would think.

Common misconception. All the stuff has to be calibrated to work together. Some of the parts out there are calibrated to work with certain other parts but what may work on a 302 doesnt always work on the 351. Some of the calibrations they use are crutches that lie to the computer by not reporting actual airflow so when a engine like a larger 351 can use that extra airflow well the calibration goes right out the door. Not to mention that a large cam can really throw stuff for a loop. The stock tune can a only do so much on a modified engine you would be suprised at how much power a simple retuning of the ECM can gain you. Not to mention overall driveability. even more true with a 351W that has a fairly big cam. Half his issue is probably with that cam and its lobe seperation. that the stock computer doesnt like.

ransil · Jun 10, 2012

this place is close to you, they can do a dyno tune

http://www.amazonracing.com/location.html

gravy · Jun 10, 2012

Is the mass air calibrated for 24lbs injectors? It should run ok with out being tuned-

xcntrk · Jun 10, 2012

I would assume with a 75mm MAF and 24lb injectors, you will need to change your MAF and Injector scaling.

http://support.moates.net/2012/04/14/ford-tuning-injectors/

Broncobowsher · Jun 10, 2012

It will need a tune. It will not "self learn" mis-matched parts. What little the self learn will do is simply build variation of stock parts. Not complete changes in nearly every parameter of the engine compared to stock.

Ghost Pony · Jun 10, 2012

I've been suffering with startup issues for 2 years. 75mm MAF housing and 24lb injectors, and comp cams extreme 4x4 camshaft, A9L, and a upper and lower lightning intake. After searching the mustang threads I finally woke up and realized that my computer was not reading the MAF properly. I took out the 24lb injectors for 19’s and got a 55 mm MAF out of a 93 Taurus. (there are quite a few models out there that have compatible MAF since mustangs are a little hard to find in wrecking yards these days).

I assumed that because I had a 351w that I would need the bigger maf and injectors. I was dead wrong. The stock MAF is 55mm and 19 lb injectors are plenty big for a 351 making 320 hp or less! Do it this way and you should not require a tune to make it run well. However, if you want to run the parts you've got you will definately need a tune.

Happy ending is I spent 20 bucks on the MAF and 19lb injectors. Starts and runs like a champ now. Basically, like I always expected out of fuel injection. I used to have to babysit it on warm up like it had w carburator with no choke. No longer, cranks and runs like my 2007 f-150 now. My advice is sell the 24lb injectors and get a stock MAF. if your not happy after that your only out 40 or 50 bucks!

z70what · Jun 10, 2012

Ghost Pony said:
I've been suffering with startup issues for 2 years. 75mm MAF housing and 24lb injectors, and a hot cam(I'd have to look, but I think it is a performer as well), A9L, and a upper and lower lightning intake. After searching the mustang threads I finally woke up and realized that my computer was not reading the MAF properly. I took out the 24lb injectors for 19’s and got a 55 mm MAF out of a 93 Taurus. (there are quite a few models out there that have compatible MAF since mustangs are a little hard to find in wrecking yards these days).

I assumed that because I had a 351w that I would need the bigger maf and injectors. I was dead wrong. The stock MAF is 55mm and 19 lb injectors are plenty big for a 351 making 320 hp or less! Do it this way and you should not require a tune to make it run well. However, if you want to run the parts you've got you will definately need a tune.

Happy ending is I spent 20 bucks on the MAF and 19lb injectors. Starts and runs like a champ now. Basically, like I always expected out of fuel injection. I used to have to babysit it on warm up like it had w carburator with no choke. No longer, cranks and runs like my 2007 f-150 now. My advice is sell the 24lb injectors and get a stock MAF. if your not happy after that your only out 40 or 50 bucks!

This was my next plan of action.. pick up the 19lbs injectors and a 55-60mm maf. if that didn't work, i was going to try and find someone to tune this sucker. My next question is.. do you have to have the SPOUT connector installed? I do not have one in my Summit Racing 5.0L harness, and can not locate any after market spout connectors. i have the plug for one on the harness, but do not have the connector. Thanks guys. I'm going to get this straightened out one way or another!

Luke

Ghost Pony · Jun 10, 2012

Maf

Thought I'd post this up too. Took a little digging, but found this on one of the mustang forums.

1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,

Thunderbirds and Taurus's of similar years will also work.

Ghost Pony · Jun 10, 2012

Yes, the spout connector should only be disconnected when setting the timing. That would be the first thing I'd fix. With it disconnected your computer can not advance or retard the timing for changing condition. Fix that, and try it. Guys, correct me if I'm wrong, but you should be able to use any type of connector you can get a hold of.

I think that's only part of the problem and a 55mm MAF and 19lb injectors will do the trick. I was blown away by the difference.

Ghost Pony · Jun 10, 2012

I reread your last post. Are you missing a spout connector completely or are the 2 connectors incompatible?

You said summit racing harness. Is it a painless wiring harness?

Bronk · Jun 10, 2012

I agree If the spout connector is disconnected , I'm pretty sure the computer will stay in open loop (factory default run)

barronj · Jun 10, 2012

I'm just speaking from experience. Perhaps a 351 is a total game changer, but in my younger days of working on my own mustangs, either 302/306/347 based mills, I've run the Holley Systemaxx, a GT40 & a Cobra, an Edelbrock RPM that was fully ported, and probably another I'm forgetting. I've run the Wolverine blue racer, X cam, E cam, a B cam, an Xtreme Energy comp cam, either edelbrocks or AFR heads, almost always a pro-m meter (never did run a C&L)... a dozen differerent combinations. These were daily drivers, and I never, in 5 years of swapping aftermarket parts, ever have a tune. They all ran splendidly well.

The only time I ever hurt a motor b/c of no tune was when I had a Vortech V-1 (14#), custom lunati cam, AFR heads, holley systemax intake, and I broke a ring-land due to detonation- I needed a tune on that combo for sure, to take out timing under boost. That was my only experience with boost- I went back to using nitrous.

I know there are some sage board members telling me otherwise, but I will stand my my original statements, and say that the system will function with those parts, you've made a mistake somewhere, and the tuner will find it.

Broncobowsher · Jun 10, 2012

...and would have ran even better if they were tuned. I know plenty of engines that run great while completely out of tune. But get them right and they really wake up.

xcntrk · Jun 10, 2012

You need to properly select your EFI components based on how much expected power your engine build is likely to create. Don't just slap 19lb injectors and a 55mm MAF on there because that's what the PCM is designed to run with. You could be robbing yourself of power if your engine is built. That setup is intended for a maximum output of about 275hp.

Here's a great read explaining the various injector & maf sizes common to the Ford EFI platforms. Just know that if you select larger than 19lb/55mm maf you have to scale the injector and maf tables accordingly to compensate for the difference.

http://www.fordracingparts.com/download/tipsPDF/ProperlySelectingEFIComp.pdf

barronj · Jun 10, 2012

broncobowsher said:
...and would have ran even better if they were tuned. I know plenty of engines that run great while completely out of tune. But get them right and they really wake up.

I'm not saying I wasn't leaving HP on the table. I'm saying that cobbled together aftermarket parts can work together. I'm not suggesting 19# injectors with a cobra meter, or anthing like that. Each component can be a different manufacturer (= cobbled together), and it should run.

KyleQ · Jun 11, 2012

I would fully expect that to run as well - maybe your issue is somewhere else. I've got a similar setup with Trick Flow heads and I'm planning on running it without a tune for awhile -

Ghost Pony · Jun 11, 2012

How much horsepower do you guys think he's making with this setup? My setup is pretty close to what he's got and I was having identical issues.

My advice is to get it to run right with the 55mm MAF and 19lb injectors. Then from a stable good running engine you can work on getting more performance out of it with bigger injectors/ tune etc. I may do this, but now I'm confident that I can make it run properly, if I change something in the future and it runs worse I'll have a better understanding of what is happening. Bottom line, your looking at $20 to make it run correctly. If you bought a C&L MAF and a tune? $500 to $600 bucks?

Please post up what hp you guys think we are making and estimated cost of maximizing hp with calibrated MAF and a tune. You can always use a few more HP when the budget allows.

Your first order of business it to get that SPOUT issue fixed.

PCM Tune needed for my 5.8L and A9L

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