Idle driving me crazy

[BLKHAWK611]

My 95 GT convertible was gift to me by the original owner. The GT has been sitting in a garage for three years and only being started twice a month and then driven around the block. it had only 98,000 miles on it. I picked it up and it would start but die within twenty feet after in gear. I had the car towed home. The things that I have replaced new; MAF Sensor, Air Charge Sensor, IAC, All Vacuum lines, TPS, Distributor, sparks plugs and wires, IFM, Air filter, Battery, Alternator, Throttle body, Coolant Temp Sensor, PCV and mesh, Fuel Pressure Reg and Fuel Filter and Fuel pump. After replacing all these things I still have rough idle and real bad bucking (strong Surging) at 1100 RPM, it idle at 650 RPM for three minutes and then drops to 500 RPM and then the lights flicker and the car want to die. Any help with this surging and idle problem.

 

[cobrajeff96]

What's the voltage level on the battery? And is the alternator even charging it?

 

[ttocs]

probably just a vac leak on some 20 yr old lines. Get a cigar and do a smoke check

 

[BLKHAWK611]

deleted

 

[BLKHAWK611]

What's the voltage level on the battery? And is the alternator even charging it?

New Battery and 200A Alternator

 

[BLKHAWK611]

probably just a vac leak on some 20 yr old lines. Get a cigar and do a smoke check

All Vac lines were changed out to new Silicone Vac lines

 

[ttocs]

it is hard to do them all and even then we have seen leaks around the TB bearings and other areas. A smoke check takes a few minutes, costs next to nothing and will tell you for sure.

 

[weendoggy]

Did you set the TPS, what's the fuel pressure, how did you set timing? A lot to figure out if we don't know.

 

[kbrandt]

This may be silly, but have you put fresh fuel in it? No amount of tuning will compensate for 3 year old fuel.

 

[BLKHAWK611]

This may be silly, but have you put fresh fuel in it? No amount of tuning will compensate for 3 year old fuel.

been driving it for six months, just rough Idle and it feels like i have a big cam with large lobes

 

[BLKHAWK611]

with the help of someone. suggested to try a new Mass Air Flow sensor. Delphi $114.00, all my problems solved. no hard starts and idle is on point and adjustable. Happy Test Drive

 

[RAU03MACH]

very good glad you were able to fix it

 

[BLKHAWK611]

For those who requested pictures 1995 GT Convertible. Daily driver

 

[Terrorist 5.0]

Here is an idea, try UNPLUGGING your MAF and run it. From what it sounds like, the problem is there all the time, hot or cold. If you unplug your MAF and the car runs good, then you at least have a proper lead.

So far it looks like you just changed a bunch of stuff and hoped for the best, and I can’t blame you. Many people including myself do that with an educated guess and hit the mark most of the time.

A 500 RPM idle is pretty low in my opinion. I would bump that up some to about 600-700. That is where most of these cars sit and idle. An idle too low can cause the lights to flicker if the alternator spins too slow, especially with under drive pullies if the idle isn’t bumped up a little to compensate.

 

[Terrorist 5.0]

My bad, didn’t see the car was fixed already haha, glad you got it fixed. Beautiful interior too, apart from the missing carpet.

 

[BLKHAWK611]

Under construction my 2002 Gt 4.6 2v

 

[BLKHAWK611]

My bad, didn’t see the car was fixed already haha, glad you got it fixed. Beautiful interior too, apart from the missing carpet.

it's all put together now and I am happier that the Idle problem is fixed. Now to replace the Air conditioning components.

 

[BLKHAWK611]

All Vac lines were changed out to new Silicone Vac lines

Did you set the TPS, what's the fuel pressure, how did you set timing? A lot to figure out if we don't know.

TPS set, Fuel Pressure at 40 PSI, Timing set by timing light at 0 degrees with spout connector out. only using 93 octane fuel

 

[weendoggy]

Did your '95 have a 4.6? The 5.0 didn't have that low of timing that I remember, even with spout out. Also, your '02 pics don't look like an '02 body style. You sure that's an '02? Just curious.

 

[ttocs]

I gave a funny look at 0 degrees as well but I am not the motor dude.