Fox 347 Combo Mix Up.

thegerm1

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Dec 6, 2010
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Hey guys I just recently picked up a 92 mustang with a 347 stroker. The car runs like crap. I figured it was due to the combination of parts. The guy I got it from seemed like he lost interest and threw parts on it to sell it.
347 stroker
F303 Cam
Windsor Sr. Heads
80mm throttle body
Unknown MAF. The sensor looks stock but the tube has to be at least 85mm or bigger.
Stock injectors and intake.
Bbk long tube headers

The car loads plugs up so fast I can barely run it to move it from one side of the barn to the other lol.

I pulled the upper and lower intake, injectors and MAF setup. Locally a guy has 42# injectors, and a pro-m Maf setup for 42's. Is this to much for this setup?

I did get a professional products typhoon lower intake and a edlebrock elbow with the car, but it needs fuel rails and they are on back order for about a month. I'm not sure if this is a good intake to run or not? It's setup for EFI or I can block the injector holes and bolt a carb on it.
Also a friend has a trick flow track heat intake that I can try....
This is my first Mustang, I've worked on them quite a bit when I was a mechanic but I never modded them in those days.

Thanks!
 
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You mentioned in the Welcome Wagon thst it had 19# injectors? My suggestion, get those 42# injectors along with the maf calibrated for them, a 70 or 75mm throttle body and that track heat intake. They are much more suited to your 347
 
Looks like someone stripped off the good parts and threw stock parts in there for the meantime. That's why it's running like garbage. Stock intake, stock injectors, stock MAF on a 347 is suspect of this.

That's a pretty big injector, I run 30's on my 347 with Pro-M 80MM MAF. I'm also running a Holley Systemax intake with ported elbow and 75MM TB.

Those alphabet cams were good in the 80's when there wasn't such thing as a custom cam or there weren't many choices. My custom grind is from COMP and it's sick. I'd ditch the F cam.
 
Good advice so far. You can make the F cam work, but if it were me, I'd get a cam from Ed Curtis made. It will be about $50 more than an OTS cam and made specific for your setup. The 42's are a bit much but if you can get them cheap with the MAF, you can adjust the FP for them and stil have room to grow. Same for the TB- a larger than needed one won't hurt you, but it won't add anything. I would get either a Systemax, Performer II, or TFS R intake. Make sure you check the springs on those heads - you want to make sure they have enough pressure and are strong enough for a different cam.
 
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Note about big injecvtors and reducing the fuel
Good advice so far. You can make the F cam work, but if it were me, I'd get a cam from Ed Curtis made. It will be about $50 more than an OTS cam and made specific for your setup. The 42's are a bit much but if you can get them cheap with the MAF, you can adjust the FP for them and stil have room to grow. Same for the TB- a larger than needed one won't hurt you, but it won't add anything. I would get either a Systemax, Performer II, or TFS R intake. Make sure you check the springs on those heads - you want to make sure they have enough pressure and are strong enough for a different cam.

Note about big injectors and reducing the fuel pressure to get them to flow less. Yes, it can be done that way. The negative side is that if you reduce the pressure, it can also affect the atomization pattern.

You would need to drop the fuel pressure down from 39 PSI to 20 PSI to get the 42 lb. injectors to give same flow as a 30 lb. injector. That doesn't sound like a workable plan to get any kind of consistently good spray pattern from the injectors.

See http://users.erols.com/srweiss/calcpchg.htm to get the calculator I used to get this answer.
 
Tried to pull codes from the car and didn't get anything. In fact I don't even see the check engine light come on.

My friend also has a set of 24# injectors but if have to get a Maf. Sounds like I'll need to go 30# though.
Does anyone run e85 in these cars. I'm coming from the GM world here and I run e85 in my turbo 3800.
 
If you are keeping those heads and other top end parts, 24's will be fine.
If you are going to a more potent head (not in the future, now), use 30's.

First things first, get the meter and injectors settled, if not it won't ever run right.

Unfortunately for you, that entire setup probably needs to be reworked.
Sounds like it was built from the "leftovers" pile.
 
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So I can't seem to figure out why I can't read codes on the car. Seems like the check engine light doesn't come on at all. Even rotating the key when all the lights self test it doesn't light up.
A friend is lending me his Maf that is setup for 24lb injectors. I have a set of 24#r's that came with the car. I guess I will be throwing those in with the trick flow intake once
I figure out the check engine light situation.
 
You can pull the codes using a test light as well. The reason for the no CEL could be deeper then just the dash light, but if that is all thats wrong, the test light method wil work for you.

Joe