98 cobra help

[98cobrafaf]

my 98 cobra has a problem with falling on its face most the time after 4000 rpm i think its a bad injector. i get blew out by stock gts and cobras and i have 373 gears and 6speed..whats the highest injector i can get with out having to upgrade anything yet

 

[FoxFour]

Before doing that, have you done a basic diagnosis of the car and engine? How are the condition of the spark plugs and wires? Changed the fuel filter? Can you give us more specifics on the mods done to the car and what's the mileage? Any trouble codes. I suspect it's something simple.
BTW, do you feel the IMRC's kicking in at around 3500 rpm? It's possible that the blades are sticking or shut closed and that would effect power above 3500

 

[98stangerSVT]

My car did that for a while. I put on new plugs and MSD wires on and holy crap did it make a huge difference. Now it doesnt skip a beat to 6800. I would definately look into that.

 

[na svt]

my 98 cobra has a problem with falling on its face most the time after 4000 rpm i think its a bad injector. i get blew out by stock gts and cobras and i have 373 gears and 6speed..whats the highest injector i can get with out having to upgrade anything yet

What do you mean by "highest injector?" A higher flowing injector will not get you any more power and will require a tune. So basically you will spend $600 and get no more power.

It sounds like your IMRCs are stuck closed. BTW, 3.73s and a 6 speed are not a good mix for a B headed Cobra, or any cobra for that matter.

 

[03bluemach]

just wondering why you stated that NA can you explain why ?.. i was planing on swapping my 4:10's for some 373's that i have laying around ... i was always told lower gears with a centri, to prevent it from blowing through the power band , and to let it have time to build boost.. ..thanks mike

 

[na svt]

just wondering why you stated that NA can you explain why ?.. i was planing on swapping my 4:10's for some 373's that i have laying around ... i was always told lower gears with a centri, to prevent it from blowing through the power band , and to let it have time to build boost.. ..thanks mike

A six speed has a higher first gear and 3.73s are a high gear for a n/a 4v. n/a 4vs need at least a 4.10 gear, 4.30s are better and 4.56s are the best for the track.

The OP said nothing about FI.

Fi does require less gear and 3.7s or 4.10s work great with a centri. I would opt fot 4.10s if I had a 6 speed.

 

[98cobrafaf]

my car has a186000 miles compression is good replaced spark plugs and wires i did imrc delete and replaced fuel filter and pump just replaced the clutch tob tob sleve clutch arm and pressure plate.. it rips then it just doesnt have hardly any pull

 

[PSUCOBRA96]

did u have the car tuned after the imrc delete

 

[kwikie]

did u have the car tuned after the imrc delete

Bingo^^^^^

 

[FoxFour]

Bingo^^^^^

Betcha there's the problem.

 

[98cobrafaf]

its did it befor the imrc delete

 

[Chris98vobra]

it rips then it just doesnt have hardly any pull

What does that mean?

 

[na svt]

did u have the car tuned after the imrc delete

Even without a tune the car would pull as hard or harder with the deletes.

 

[98cobrafaf]

i did the imrc delete to c if that was the problem and it wasnt it just fails

 

[tktlwyr]

You don't need the car tuned with IMRC delete and if you're running NA you definitely do not need more injector.

Does the car have a miss while idling? It might be worth pulling all the plugs and taking a peak at them to make sure they're all firing. You changed the plugs and wires, how's the coil? Stock Ford coils are prone to leaking as they age and would now be the weak link in the ignition. Also, did you change or mod the mass air meter/filter lately? Finally, there's a possibility that the fuel pump is defective.

 

[crash549]

i did imrc deletes and haven't got it tuned yet. the car runs, for the most part, just fine.

 

[98cobrafaf]

i bought coils awhile back its firing right it acts like it isnt getiing enough fuel after 4500