After TFS h/c/i swap, car runs rich + stalling...

90bluegt · Aug 8, 2006

I wouldn't think about running 30# injectors on my combo. That would be some serious over kill, ether that or get a fuel pressure regulator and turn the pressure way down.

RaceDvr50 · Aug 8, 2006

5spd GT said:
30's are overkill. They are not needed. If you don't run with Grn92lx has, then he thinks you are wrong

24's would be more ideal.

I have 30's on my car, it is "overkill", they are not needed. 24's would be more ideal. I had actually read of a case where a user installed 24's and he said his car ran smoother and was quicker at the track compared to his 30's. A more lean powerband.

+1 for overkill, you ALWAYS should go to the low side of what you need and use the fuel pressure to compensate. I know jrichker has a chart on what pressures you can run to get certain flow rates from your injectors and a smaller injector can flow more fuel than the next injector size up if you crank up the pressure. Also if you run your fuel pressure too low the injectors won't atomize properly and you'll get incomplete combustion and sluggish performance with poor mileage.

millhouse · Aug 8, 2006

RaceDvr50 said:
+1 for overkill, you ALWAYS should go to the low side of what you need and use the fuel pressure to compensate. I know jrichker has a chart on what pressures you can run to get certain flow rates from your injectors and a smaller injector can flow more fuel than the next injector size up if you crank up the pressure. Also if you run your fuel pressure too low the injectors won't atomize properly and you'll get incomplete combustion and sluggish performance with poor mileage.

Sure they may be overkill...but chances are they are not detrimental to his combo. Seeing as he already has them, I myself see no need to swap to 24lbs. They will allow him to grow a bit also.

If anyone is interested, there is a lil calculator as well as a chart here... http://www.megamanual.com/v22manual/minj.htm

Just scroll down a wee bit and you'll see it.

1990Coupe · Aug 9, 2006

I cleaned the IAC, still same thing.. i still think i may get a new one, cant hurt, its fugly as heck. Also i need a voltmeter so i can check/set the TPS, no idea where its at. I still think the injectors are over kill like some of you, my recent trip to the gas station yeilded im getting 12 MPG..... and i dont get on it often!

5spd GT · Aug 9, 2006

He is okay with the 30's, just saying that they are not ideal, that is for sure. Some on here post some incorrect info because the part is what they have or had. Some can't see past there own bias.

QDRHRSE · Aug 9, 2006

I hate seeing posts that recommend buying something because "there's room to grow". That's a bunch of horse*****. You should buy whatever your combo needs. Most people never finish cars much less grow combo's. A 255 pump is the only "room to grow" item that makes sense to me. That being said I think that in his case there's not much of difference between 24's and 30's. Keep in mind that tuning will be different for each. The 30's will need less fp. I don't think that the engines temps are an issue here but colder is richer- just keep that in mind. With a 180 stat the car should be fine. If the car isn't getting hot enough, it may not be going into closed loop operation....I don't think that's the issue at hand but you never know. How many miles are on the car? It may also be a good time to change O2 sensors as well.

millhouse · Aug 10, 2006

QDRHRSE said:
I hate seeing posts that recommend buying something because "there's room to grow". That's a bunch of horse*****. You should buy whatever your combo needs. Most people never finish cars much less grow combo's. A 255 pump is the only "room to grow" item that makes sense to me. That being said I think that in his case there's not much of difference between 24's and 30's. Keep in mind that tuning will be different for each. The 30's will need less fp. I don't think that the engines temps are an issue here but colder is richer- just keep that in mind. With a 180 stat the car should be fine. If the car isn't getting hot enough, it may not be going into closed loop operation....I don't think that's the issue at hand but you never know. How many miles are on the car? It may also be a good time to change O2 sensors as well.

Well...just for you then perhaps well call it "preparing for the future".

I really don’t see anything wrong with it myself. Let's say an individual has a 100% stock foxbody and he decides to upgrade is perfectly fine rear suspension. Now…he may not see any appreciable gains whatsoever in stock form…however if he decides to bolt on some gears and slicks he'll much more prepared if/when the time comes. There are so many instances where "room to grow" is commonplace. What is seen now as overkill can be seen in the future as a necessity. I myself prefer to think of what I'll be doing ahead of time and trying to prepare for that.

1990Coupe · Aug 10, 2006

Well if anything in the future i wanted to add an SC trim - not the biggest of superchargers but its something - so ill stick with the 30lbs,,, but do you guys think that is whats causing my horrid gas mileage?

millhouse · Aug 10, 2006

1990Coupe said:
Well if anything in the future i wanted to add an SC trim - not the biggest of superchargers but its something - so ill stick with the 30lbs,,, but do you guys think that is whats causing my horrid gas mileage?

Not unless your fuel pressure or maf is screwed up.

I'd look into the O2 sensors as QDRHRSE suggested.
Have you gotten your codes pulled yet?

1990Coupe · Aug 10, 2006

Yes all i pulled was an egr code, a neutral safety code, and a map sensor malfunction (fixed that and still same stuff happens). Im going to check the o2's tomorrow see if they look old and beat, also set the TPS and look into the MAF see if it looks dirty or what...

RaceDvr50 · Aug 10, 2006

Is the performance good? Do you know what the fuel pressure is? I've seen major changes in performance based on fuel pressure and even though Ford's SVT teams opinion that fuel will not atomize properly below 40psi on injectors 24lbs and bigger is often argued in here I have multiple examples of how correct it is. So make sure your pressure is up to at least 40 and let the computer and O2 sensors sort out your mixture. Your other issues like the IAC and the TPS are good areas to check for stalling and surging but I don't think they are gonna cost you that kinda mileage.

QDRHRSE · Aug 10, 2006

RaceDvr50 said:
Is the performance good? Do you know what the fuel pressure is? I've seen major changes in performance based on fuel pressure and even though Ford's SVT teams opinion that fuel will not atomize properly below 40psi on injectors 24lbs and bigger is often argued in here I have multiple examples of how correct it is. So make sure your pressure is up to at least 40 and let the computer and O2 sensors sort out your mixture. Your other issues like the IAC and the TPS are good areas to check for stalling and surging but I don't think they are gonna cost you that kinda mileage.

I agree. For some reason 24lb injectors really seem to work better at higher pressures. I know that every car is different but I have had more than one car that liked the fp anywhere from 44-48 psi.

1990Coupe · Aug 10, 2006

Ill check the FP.. should i check it with the vac hose off or on? and it idle or WOT? the gauge is under the hood so it would be hard to see at WOT LOL!.. anyways as far as performance goes - when i got the car and fixed the bugs, for a HCI car i wasnt very impressed.... sure its loud, and spins the tires and bla bla, but if im in 2nd, or 3rd about 2500 and stomp on it,, its not impressive AT ALL... kinda is doggish until about 4200 and up.... Ive never really had a HCI car like this before tho, just a car with an ecam and 351 heads... so i was kinda dissapointed.. maybe its an underlying problem? could be the same problem causing the stalling and bad gas mileage... ill let you guys know what happens, i dont have time for a couple of days to work on it..

5spd GT · Aug 10, 2006

Check it with the hose line off the fuel pressure regulator and at a warm idle.

Good Luck!

ninety15.0 · Sep 13, 2006

Im having the same problem...let me know if you find anything.

1990Coupe · Sep 14, 2006

No same problem. this weekend ran into an issue where i stalled on RT 9 by my house, and i would re-start and it would stall again.. didi that about 4 times before i started it, revved and let the clutch go and kept it driving.. i think its the IAC i have to take it off and clean it and ill see what happens there.

Fuzion · Nov 24, 2006

1990Coupe said:
No same problem. this weekend ran into an issue where i stalled on RT 9 by my house, and i would re-start and it would stall again.. didi that about 4 times before i started it, revved and let the clutch go and kept it driving.. i think its the IAC i have to take it off and clean it and ill see what happens there.

+

Did you ever Resolve this problem?

86bluecobra · Nov 24, 2006

looks like you succsesfully hijaked aliate X post 1990coupe.
As for the original problem i wonder if the maps sensors is faulty. i know in Maf cars it is called something else its the BP sensor. What it does on a Mass air flow car is read the outside or barometric pressure so that the fuel injection will compensate for different elevations. Could it be it is giving the computer the wrong info and you are adding fuel for the wrong altitude? Just a thought. don't know if it is a problem with the Mass cars but it could be.

1990Coupe · Nov 26, 2006

Fuzion said:
+

Did you ever Resolve this problem?

yes and no - i replaced the IAC and ACT sensors since they were throwin codes. I narrowed it down to the TPS not being set right but even when i think i have it "right" it still does the same thing only with different characteristics.. Oh fuel pressure is 30 with vac on, and 33 with vac off..

1990Coupe · Nov 26, 2006

86bluecobra said:
looks like you succsesfully hijaked aliate X post 1990coupe.

sorry!

After TFS h/c/i swap, car runs rich + stalling...

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