Low on power?

[the5.ohh]

Weird thing happened with my car recently. Noticed it like 3 weeks ago. Was driving and had a full tank of gas and 2 other people in the car and it felt like every time I tried to accelerate something was holding the car back from going faster. What it felt like was I'd hit the gas, whether it be hard or normal, and it was just lugging to get up to speed. Didn't pay much attention to it since the car was packed and had a full tank of gas. But. I was driving it today and it was fine, driving it home after shutting the car off a bunch of times (running errands), it felt the same. I had an injector replaced like 3 months ago because the car was running funny. Anyone know what I should check into?

 

[DeepList]

Kinda sounds like it's being starved... have you tested the fuel pressure?

 

[Ferocious]

Fuel, air, spark. Check all 3.
I'm more than positive you'll find your problem.

 

[the5.ohh]

Kinda sounds like it's being starved... have you tested the fuel pressure?

No I haven't yet.

Fuel, air, spark. Check all 3.
I'm more than positive you'll find your problem.

Will do, thanks dude.

Not trying to be a p.i.t.a but how would I check them?

 

[Ferocious]

If you have a vacuum leak your idle may be off a little. How's the car when at a light?
You can check for leaks by spraying brake cleaner or wd40 around the hoses while the car is idling and listen for a change in idle.
You can also try cleaning your MAF since I know you've tampered with that.

As for fuel, you can hook up a fuel pressure gauge to the shrader valve located by the fuel rails.
You can test fuel pressure with the car off, on the on position, and with the motor on.
You fuel pump might be on its way out or your filter might be clogged.
It could also have been a case of bad gas which is why it doesn't happen all the time.

Ignition you can just pull your wires and clean them off a bit. Maybe one of your spark plugs is on the way out (though you would more than likely feel a misfire in that case).
Sluggish acceleration can be a million things.

 

[the5.ohh]

If you have a vacuum leak your idle may be off a little. How's the car when at a light?
You can check for leaks by spraying brake cleaner or wd40 around the hoses while the car is idling and listen for a change in idle.
You can also try cleaning your MAF since I know you've tampered with that.

As for fuel, you can hook up a fuel pressure gauge to the shrader valve located by the fuel rails.
You can test fuel pressure with the car off, on the on position, and with the motor on.

Ignition you can just pull your wires and clean them off a bit. Maybe one of your spark plugs is on the way out (though you would more than likely feel a misfire in that case).
Sluggish acceleration can be a million things.

I'll try some of this later when I get a chance. The plugs and wires were put in when I got the car last Sept., ngk iridium plugs and frpp 9mm wires. As for how it idles at a light, it seems fine to me. I idle at like 700 in park. Once i put it in drive it drops to like 400 I think, and sometimes it stalls in drive, and sometimes in reverse. Car surges forward in drive and backward in reverse, rpms jump up when it does that and feels like its gonna die on me. The maf is a C&L 76mm, was put in the car in late December, never touched it since lol. Thanks for the tips

 

[5-oh-MUSTANG]

I'll try some of this later when I get a chance. The plugs and wires were put in when I got the car last Sept., ngk iridium plugs and frpp 9mm wires. As for how it idles at a light, it seems fine to me. I idle at like 700 in park. Once i put it in drive it drops to like 400 I think, and sometimes it stalls in drive, and sometimes in reverse. Car surges forward in drive and backward in reverse, rpms jump up when it does that and feels like its gonna die on me. The maf is a C&L 76mm, was put in the car in late December, never touched it since lol. Thanks for the tips

Dude your idle when its in drive is wayy too low. Mines around 800 rpms. Thats would explain why ur stalling.

 

[Ferocious]

Yeah my car idles at around 500-700 at a light when it's warmed up.

400 seems really low. That may be something to look into.

 

[the5.ohh]

Dude your idle when its in drive is wayy too low. Mines around 800 rpms. Thats would explain why ur stalling.

I'll go double check it right now, brb! It does seem low lol

 

[the5.ohh]

Could my torque converter be going out?

 

[the5.ohh]

Heres where it idles in drive. Sometimes when i put it in drive the rpms jump up and the car stalls, does the exact same thing in reverse.

 

[white95]

If your convertor was on the way out, you'd have more problems besides low power. You may experience a bad shuddering or it might even not move at all.

 

[Ferocious]

With 50000 miles I highly doubt it has anything to do with the tranny.

Your problem sounds fuel related if you ask me.
Does the car drive better after you've been driving it for a while?

 

[the5.ohh]

With 50000 miles I highly doubt it has anything to do with the tranny.

Your problem sounds fuel related if you ask me.
Does the car drive better after you've been driving it for a while?

Yeah I'm just shootin ideas around lol. Idk dude its weird, it can run like a top but then feels like its a slug lol. I just drove the car to my grandparents house, bout 4-5 hours after i last drove the car to the stores when it was acting weird, now its running fine.

 

[the5.ohh]

Should i try tightening the set screw on the IAC?

 

[white95]

Most people only do this when it causes a problem but you SHOULD change the transmission fluid at 50k miles. You wont regret having a healthy transmission.

 

[DeepList]

Still sounds like it's starving for fuel to me.

 

[Ferocious]

Is your CEL on?

 

[toyman]

As mentioned, confirm the fuel pressure before jumping to a dozen other conclusions. Starting from the top.

Why do you have a C&L 76mm. Did you change the injector size?

The best spark plugs are plain and cheap copper core. Rare earth metals are not the answer.

The IAC should control the idle as the load changes when at idle such as the AC coming on or shifting into gear from Park or neutral. The IAC has no performance affect at speed.

Factory idle for an auto is commanded by the ECU to be 700 rpm. Your idle is correct.

A TC issue will be one of it slipping or shuddering especially on the 3-OD shift. There is nothing to indicate that it's an issue.

Don't mess with the IAC air bleed screw. It's just for ultra fine tuning of idle quality. Your idle issue points to the IAC.

Have you pulled trouble codes and if not why not. You need to know what the ECU is logging. You DO NOT need to see a CEL for trouble codes to be present.

 

[RichV]

1. Check codes.
2. Swap for the stock MAF. See if runs better.

You really don't have many mods, and 50K miles is nothin'. You may have a O2 sensor or something simple going on.