91 Lx With Twisted Wedge Running Like **** Under 2k

[gagemotorsports]

Hey guys,

New to the forum and just picked up a 91 LX notch. Had a few back in high school and really wanted another...That said car needs a tune.....or not? Car is almost undrivable under like 2k if im not in the skinny pedal. Over 3k it runs like a champ. Car almost dies every time i come to a stop, cold start runs like crap for like 30 seconds then clears and idles great. When just trying to crusie down my street in 3rd gear at 1800 rpm it bucks jumps. drop it down to 2nd and bring it over 2k its drivable.

This is whats done.
Full top end kit twisted wedge
70mm throtle bodie
30 or 35 lb injectors
High pressure fuel pump
intake and mass air
Shorty headers
full x pipe no cats with flowmasters
MSD ignition setup

Im pulling the motor in winter and probably gonna put a charger on it so i really dont want to spend $800.00 to have it tuned at a shop. I do have a Bama tuner that i can send back and get a close tune for my set-up but i know people have done the same as me and wanted to see if anyone had any suggestions on what i can possibly do without a tuner to get this thing to run right...or if a tune is the only option.
Thanks in advance for the help
Eric

 

[Davedacarpainter]

The injectors are kind of big, don't you think?

I'm going to move your thread to the tech side. You'll get more of the detailed help there.

 

[FoxMustangLvr]

Hey guys,

New to the forum and just picked up a 91 LX notch. Had a few back in high school and really wanted another...That said car needs a tune.....or not? Car is almost undrivable under like 2k if im not in the skinny pedal. Over 3k it runs like a champ. Car almost dies every time i come to a stop, cold start runs like crap for like 30 seconds then clears and idles great. When just trying to crusie down my street in 3rd gear at 1800 rpm it bucks jumps. drop it down to 2nd and bring it over 2k its drivable.

This is whats done.
Full top end kit twisted wedge
70mm throtle bodie
30 or 35 lb injectors
High pressure fuel pump
intake and mass air
Shorty headers
full x pipe no cats with flowmasters
MSD ignition setup

Im pulling the motor in winter and probably gonna put a charger on it so i really dont want to spend $800.00 to have it tuned at a shop. I do have a Bama tuner that i can send back and get a close tune for my set-up but i know people have done the same as me and wanted to see if anyone had any suggestions on what i can possibly do without a tuner to get this thing to run right...or if a tune is the only option.
Thanks in advance for the help
Eric

Some of the driveability issues sound like it could be cam related. With some high rev high lift cams you will have bog issues below 2k rpms. Do you know what cam you have? What gears are currently installed in your rear axle? Some cams (like a TFS stage 2 cam) require a 3.73 ring and pinion because the cam doesn't really make power until 2,500+ rpms. The car will buck like crazy with stock gears.

As far as crappy idle and grumpy cold starts, have you checked for codes? A lot of people here will tell you that Bama tunes aren't any good and can cause more driveability issues than they solve.

 

[FoxMustangLvr]

The injectors are kind of big, don't you think?

I'm going to move your thread to the tech side. You'll get more of the detailed help there.

If he has 36# injectors on a 302 engine then that'd be big. I have 30# injectors on my HCI 306 engine which will work just fine with a tune.

 

[gagemotorsports]

Thanks so far for the responses. I will look up the cam info tonight when I get home. I did confirm I had 30lb injectors and I know i have 3.73's in the rear.

 

[FoxMustangLvr]

How to pull codes sticky
http://www.stangnet.com/mustang-for...codes-from-eec4-in-86-95-5-0-mustangs.889006/

 

[Davedacarpainter]

If he has 36# injectors on a 302 engine then that'd be big. I have 30# injectors on my HCI 306 engine which will work just fine with a tune.

Do you have forced injection? I need to go back through your thread I guess.

Bah, what do I know with two carbed foxes anyhow!

I've just read anything above a 24 would be large for a stock sized engine. Does the top end open it up well enough then to use that large of an injector? I ask this sincerely, btw.

 

[gagemotorsports]

Do you have forced injection? I need to go back through your thread I guess.

Bah, what do I know with two carbed foxes anyhow!

I've just read anything above a 24 would be large for a stock sized engine. Does the top end open it up well enough then to use that large of an injector? I ask this sincerely, btw.

Once above 2500rpm it really does pull hard and run great.

 

[Mustang5L5]

What fuel pressure you running?

Dump the codes and lets start from there

 

[mikestang63]

two words- BAMA tune

 

[deathb4dismount]

I had same problem recently, and it was the iac causing the issue. Don't skimp if you are replacing, buy motorcraft. Pull the codes and as it can help you avoid spending money where you dont have to.

 

[jrichker]

The first step is to do the diagnostic legwork: DUMP THE CODES!!!

You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix.

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 200,000 hits, which indicates it does help fix idle problems quickly and inexpensively.