Hesitating Badly. NEWBEE needs help.

[Typhoonwes]

Here is my problem:

1st, I know **** about cars, this is my first sports car. Go easy on me.
1996 Mustang GT
with a 1998 GT motor. Motor was swapped with a stock 1998 v8 4.6 GT.

1996 Motor, Unknow mods, It was fast and powerfull. It all might have been stock... with a supercharger and full exhaust system, I had a blown ring, had bad blowby and kicking oil out of the oil cap and the valve cover holes on top.

To costly to rebuild.. so i spend about $1500 motor/parts and labor. (good friend of a friend of a friend)

1998 Motor was running weird, burning fuel and start to smoke if i rev it in park or take off.. Only once its warmed up. I figured my last motor had bigger fuel injectors(i am guessing here) , and was tuned for bigger injectors... I did allot of reading before I decided that it was the injectors causing my burning fuel problem.

so I bought 42lbs fuel injectors.
I Put them in, the car works great on normal driving, the smoking from burring too much fuel went down but not all gone.
The problem now is, if i wanted to floor it from about 3000rpm's the car would Hesitate badly. I can slowly go up to 4000rps without a problem, but can't floor it. on 3rd or 4th gear.
I only put this injectors in because I think my last motor was not stock injectors.

Let me try to explain what i have in the car, I bought it as is with the 1996 motor and swapped to a 1998.
SuperCharger (unknow what type, Looks like a vortex, or a procharger. There is no tags on it.)

Fuel rails psi is about 35psi with key on, engine off. Running about 30psi.
Tested before the new injectors

42lb Fuel injectors. (i put those in)

Full exhaust system from BBK shortys to x pipes with a FlowMaster System..
Thats all i can explain right now.
Anyways.. Like i said, i am new to all this.. I am looking for help.
If you need more info, I will glad to help. If you need more info you need to tell me where to get it info...

Car has about 103k miles.
Motor has about 43k miles.

P.S.. I also have 24lb injectors ready if i have to switch to them.. also the OEM injectors that was in the motor.. might have been 19 lbs.


Thanks

If i give up, What should i sell it for? $10k??

 

[wmburns]

Reading your post, one of the questions I have is "what size injectors were in the car before the 42#'s?".

Are you aware that anytime fuel injectors are changed in size, a re-tune is required (fuel tables modified for the new size)? There is zero chance that the stock #19's will work correctly in your Supercharged car.

Do you have access to a tuner or ODB2 scanner?

How are you measuring the fuel pressure? (delta or atmospheric)? 30 PSI delta is too low. For the Mustang, the delta pressure should be 40 PSI.

While not wanting to discourage anybody, consideration should be given to having a professional dyno tune your car.

 

[Typhoonwes]

I don't know what size injectors where in there before the 42, I could not find info on it from the numbers on the injector. I am sure they are stock injectors.

The reason i changed to 42lb injectors, is because I was thinking the motor i swapped out might have had something more than stock... It might not have been 42, maybe 24.

I have a normal Scanner, I am not getting any reading yet, but i only drove it around 11miles since the battery has been pluged back in.

My friend had this fuel pressure gauge, not sure what it is.. it's in a red box, with lots of connections.

I know i will need a retune, it just wish it was not like $650 for the ECU and the SCT 4bank chip.


I was just thinking. If my pressure is about 10 to 5 psi to low, would that cause my problem and 3000 rpm flooring it??? could my Fuel filter be bad?




P.s. I am planing on buying the SCT SF3 / X3 hand held and the with Advantage III Ford Custom Tuning Software or Ford Vehicle Pro Racer Package.
Thanks. for looking

 

[wmburns]

First, there are a lot of very smart ppl on this forum. I suspect that if you posted a picture of the injectors, someone will know what they are. Post any markings as well.

I am not sure that you understand the difference between Delta and atmospheric pressure. In a boosted application, the fuel pressure should be referenced to the manifold (delta). Remember the conditions inside the intake manifold go from vacuum at idle to greater than atmospheric at load. Hence the need to reference the pressure to the manifold.

If measured at the rails at idle, it would be normal to read about about 30 PSI (the intake is actually under vacuum whereas the gauge is reading atmospheric).

Also note, if the vacuum reference is NOT attached, the FP would be too high at idle and too low under load. This would have the motor go from rich at idle to lean under load.

IMO, the best way to measure FP is via an ODB2 scanner as reported to the PCM.

Your problem could be a hundred things from a bad/dirty MAF, vacuum leak, fuel pump, pressure sensor, no manifold reference, MAF calibration, PCM load tables, ect...... All of it has to work together.

The challenge is to figure out if something is broken or this is just a bad tune.

 

[patman0911]

How about putting the injectors off the old motor on there, or do you not have access to it anymore? You know those are the correct ones for the blower and its tune.

A 96 and 98 motor are for your purposes identical so if everything is set up the same way on the new motor as the old, it should run as before. However, since you don't know the history of the old motor, you don't know what was inside it and if compression had been changed or the heads ported or different cams installed so the the tune may be all wrong for the new motor anyway. A new tune is probably in order.

The smoking sounds like bad valve seals - not uncommon for early 4.6 motors. This is more of an annoyance than anything for the short term - I'd be very concerned about driving a blown motor without confidence that the fuel system was right.

 

[Typhoonwes]

Thanks for replying, Please remember i am very new to this and learning what is what.. LIke.. .CEL, Found out that ment Check Engine Light.


I don't know the boost psi, Maybe next weekend i will put a boost gauge in.
I don't have access to the old motor.

I have 24lb/hr injector, I could trying swapping those out first before spending money on a tune. It feels like its not getting air or Fuel at open throttle. (other word for pedel to the metal????)

Here is what i did last night. I unplugged the Mass Air Flow Sensor and at full open throttle at 3000 RPM's it did not hesitate, it felt good.
So i swap out a new MAF and had the battery unplugged over night. Took it out again and the problem was still with the MAF plugged in.

So, i am thinking a re-tune is need????? Or the 24lb/hr injectors will work fine.

I am going to get it re-tune as soon as I can. I don't dive the car more than 50 to 75 per week.

 

[BurningRubber]

Whatever you do, stop going wide open throttle in the condition it is in. You could blow the "new" engine up soon enough if you are going wide open and having fuel issues (as in going lean) when you are producing boost.

And you do not need to buy a new ECU for a tune.

 

[Typhoonwes]

Thanks BurningRubber, After talking to people, I am not going to do a another ECU.

And the wide open throttle was only to test. I don't do that all the time.

 

[Typhoonwes]

any other input will help greatly.

Thanks all

 

[Midnight2V]

In 1996, all the mustang fuel systems were returnless. Somewhere through the 98 year, Ford quietly switched to the returnless fuel system. If the system on the new engine was returnless, then the fuel pump may be operating improperly. Also, changing those injectors abolutely threw off the tune, even if they were the same size.

What color were the injectors, they are color coded. 96-98 used EV1 style injectors, below is the color code. A supercharged car should have 30# minimum unless a FMU was used to boost fuel pressure up to like 70psid.

orange - 19# these are stock on those years
light blue - 24# these were stock on the cobras of those years
red - 30# stock on the thunderbird super coupes and also available in FRPP
dark blue - 36# FRPP
electric green - 42# stock on lightnings and harley davidsons and FRPP

There are higher flow levels but they do not adhere to a color code and are generally not sold through FRPP. My Siemens are all black and are 60#.

 

[Midnight2V]

My thinking is that your original setup was using an FMU which used to be a common thing in supercharger kits for NPI cars. If you threw 42# injectors in and they are running at 70# there is way too much fuel. If that's the case, you are probably running so rich that your charge cannot combust. The FMU usually only kicks in when you get to 2-3#, probably about the time you get to 3000rpm.

At this point your spark plugs are probably fouled or wetted. You need to take your car to a shop and get it tuned. Any decent shop should be able to identify the components in your build and tune accordingly. That is the only way your car is going to run properly, and you will get some vital information as to what exactly is under your hood. The only things that will be hard to tell is the cam profile and the piston dish size assuming it isn't stock.

If you know the previous owner of the engine, by all means get any information you can from him. That could prove invaluable as well.

 

[Typhoonwes]

Here are some pics.. I will get better pic later, I just found those on my phone i took Sat at my garage.

Sorry. the old motor is gone..and the last owner does not seem to want to talk to me.

This motor is all stock. The guy that put it in said its not the normal motor.. He give me two name. The one that was the 1996 and the 1998 i have now. This one i have now, i don't think i have seen pictures of it online. The oil cap is on the driver side. Too bad i don't remember the name. Winsor something like and something else...


The color injector don't match my stuff. I have some old pics of the last motor, the injectors either look black or something dark. Again.. the guy who used to own the car won't talk to me.. what an ass.. its like they got something to hide... maybe she kill him.. LOL. This car was traded in at a dealer about a year ago. It could have easly sold for at least 6k or even 8k.


I don't think i have an FMU. I am sure i would have seen it.

 

[Typhoonwes]

here is some more pics.
umm.. limited to how much i can post.. I will link it if i can from somewhere else

 

[Midnight2V]

Yeah, i can't really see anything in the pics. I would take it in to get tuned for those 42# injectors you have, they should more than handle what is on the engine unless you have a really serious cam and heavily ported heads, or your blower (looks like a powerdyne) is making over 15# of boost. When you get it to the tune shop make sure that they change the plugs, don't bother changing them until you get there.

 

[Rickyll7]

doesnt look like a stock mass airflow sensor housing. as stated above, you need a dyno tune to get this right.

Also, stop driving it or you will destroy that motor. Even driving it easy could destroy the motor. Too much fuel will wash your cylinder walls and not enough will cause detonation. both will lead to a destroyed motor and can happen no matter how you drive it.

 

[Typhoonwes]

Yeah, i can't really see anything in the pics. I would take it in to get tuned for those 42# injectors you have, they should more than handle what is on the engine unless you have a really serious cam and heavily ported heads, or your blower (looks like a powerdyne) is making over 15# of boost. When you get it to the tune shop make sure that they change the plugs, don't bother changing them until you get there.

Midnight2v!!!! YOUR THE BEST!!!

Thanks to you i now know what have. i have 6 lbs boost with this supercharger.

Also.. found out that its a kit with a Ajustable Fuel Pressure Regulator.
My guy didn't take it off and put it on the new motor. Now its all making more sence.. I am thinking now, he had 24lb/hr injectors, I went to high. 19lb/hr was too low and 42lb/hr was too hight. ( YES..i will retune for the 42lbs)

So..does this make more sence to my problem????

 

[GDawg]

I didn't read all the posts but first of all your stock injectors should be around 19#... to take them up, what are you doing? You are pushing more gas in, hence a richer mixture. Your tune is all about the AIR/fuel mixture. You need a tune if you change this mixture. There was a post here about a guy running 96# injectors or something like that and it was the stupidest post I ever saw. He had fuel smell and poor performance all over the place. Do your research before you start changing the engineered design of your engine.

You need a professional tune if you are going to change things like that.

 

[Typhoonwes]

You should read my frist post... I bought the car as in.. engine went bad..
Did not think to keep the injectors and some other parts.. now i am trying to figuer what i am missing.

 

[trombonedemon]

Get it tuned by a reputable mustang tuner like all the above post said and get yourself a Haynes/Chilton manual if your going to tinker around w/a supercharged mustang. You gotta start some where but, what a settup to start on.

 

[Typhoonwes]

LOL.. love your PIC... Beat the Stang??? LOL

Yes.. I am going to get it tuned, I am just trying to collect data from everyone. As you can tell Midnight2v
helped by know my type of supercharger, which lead to missing my Fuel pressure reg that comes with that type of supercharger kit. I would like to get everything ready, so when i go get it tuned, I either added stuff, or corrected something.. so i get it tuned and drive away happy...

If not..

FOR SALE $10k LOL.