Modded Mustang Forums banner

2001 Bullitt -- Runs kinda funny

2K views 17 replies 6 participants last post by  turboph1sh 
#1 ·
Hey all,

I have a 2001 Bullitt with about 40k miles, its been supercharged its whole life, swapped pulleys, blown trannies, blah blah blah.

As it sits now, it is setup with a standard Vortech v2 kit, no fueling upgrades, no boost increase, everything as it comes from vortech for their standard kit.

When I was younger (and dumber) I swapped the pulley out for one one that upped the boost a couple of #s . I thought I would manage the system with a handheld tuner and just reduce timing and add a little fuel.

I didn't realize that the vortech kit came with a chip installed into the ECU, so when i tried to flash the ECU it wouldnt take the changes.

Ever since that, its run very funny. It will idle fine, but revving it, it almost sounds like it has clogged Cats, it sounds like its breaking up and just isnt revving freely like it should.

It will drive under its own power fairly well, but as soon as you push the gas, it sputters a bit then goes into, what seems like, a limp mode. The idle hunts up and down and the car will eventually die. During this you can't really accelerate.

No codes are thrown, except for the rare ignition misfire.

What are your guys thoughts?

Fueling? igniton? ECU fried?

I have been slowly putting this thing back together and figuring out this is the next step.

Thanks in advance guys.
 
See less See more
#3 ·
While I don't know much about anything when it comes to superchargers, I can only comments on things I've encountered on my bolt on GT.

When I had this issue come up in the past, it was a clogged fuel filter. Idled fine but once you needed more fuel and hitting that pedal, the car would sputter then die due to lack of fuel obviously.

Have you checked pressure at the fuel rails?

Since it happened after you messed with the ecu I don't think this is your issue but just wanted to throw my 2 cents in
 
#4 ·
I appreciate your input.

I haven't really investigated yet, just trying to see if it sounded like something common. The reason it seems weird is because once I hit the gas it never recovers, it, like clockwork, will feel like it hit a threshold where it won't fix itself until it dies and when it dies I have to cycle the key to start it again. so it almost seems like the key cycle fixes it. meaning something electrical. idk tho.
 
#5 ·
Tuning is really beyond me but it sounds like the tune is screwed up. My car has a chip as well. There are two manufacturers that make chips: Diablosport and SCT. I have both. It takes a tuner with the appropriate tuning software to tune a chip. A Diablosport chip came with my supercharger kit. My installer/tuner didn't have Diablosport software so I had to buy an SCT chip to get the car tuned. My second tuner had software for both.

If you have a modern handheld you could take it to a tuner and let him tune it without the chip.
 
#6 ·
I had a similar issue on my 03 V6, and it ended up being the gas cap vent was clogged, if I left the gas cap off and drove it drove perfect. Worth a try to leave the gas cap open, won't hurt anything and easy to test.
 
#8 ·
Do you have a Wideband moniter in the car? If so check the air fuel ratio whIle idling and then if you try to get on it. For a blown application WOT should be from 11-11.7 for safety/ conservatism. Some people may run closer to 12. Idle should be reading in the stoichimetric range.
 
#12 ·
So I replaced all coils and plugs with MSD coils and NGK plugs.

The car runs way better now, but I noticed that my gas gauge doesn't work.

I went and got gas thinking it was low, but the gauge doesn't go higher than empty and the LOW FUEL light is on as well.

I ran the diagnostic in the Cluster and it shows 255 as the output which means open circuit.

I checked under the rear of the car and found this:





Does anyone know what these sensors are?

Thanks!
 
#16 ·
See if you can find a part number and reference it that way, otherwise you may be able to find a replacement or 2 or 3 at a junkyard for relatively cheap.
 
#18 ·
Ok, so I finished up this weekend and have to say that she is running very well.

Basically here is what i did:

I got a new gas tank, filler grommet, fuel filter and Fuel pump assembly. I bought a used rear body harness off ebay and cut out the 2 harnesses that I needed and spliced them into the body harness on my car.

I swapped over all evap equipment from old tank and popped the new tank in place.

It seems that the car runs good and there hasn't been any issues since.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top