Not revving....

[Loki]

Well I got the temp problem figured out, the guage isn't working so it must be grounding out somewhere or something, both my senders didn't work so I bought a gauge and it doesn't read that it's super hot. It reads normal.

Now onto my other problem.....when I go to drive the car it won't rev, well it'll rev to about 2000rpm and won't go any higher. It sounds like it's revving higher but the car isn't going anywhere and the tach doesn't go above 2000rpm. I'm not throwing any codes, the idle isn't sitting in the same spot all the time either. It goes up and down, usually sits at around 4-500rpm. When it's sitting that low when I rev the motor the lights brighten up :?

I'm really not sure what it could be, it doesn't stall and sputter it just won't rev. I have no idea what it could be, it's probably something simple but I have been up way to long today to even think. I really hope that someone on here can help me out, I wanna drive my car :cry:

 

[empera]

TPS? checked it ?

 

[IJ.]

AFM Plug?

 

[empera]

^^ wouldnt that make it sputter and idle all crazy? stall out?

 

[IJ.]

Nah they seem to idle fine just won't do jack after that though!

 

[empera]

hmmm i guess if the plug is fucked then it'll idle...

 

[IJ.]

Yep can't see it making 2000 though so probably not that....

 

[Joel W.]

Timing belt slipped?

I am glad you got your temp gauge fixed. That's a new one to me...

 

[Loki]

I'm not sure if it actually made it to 2000, I know the AFM is plugged in but if the plug is toast who knows. It worked fine when it was plugged in before. It's all the same harness and AFM as it was on the old motor.

I haven't gone near the timing belt so I wouldn't think it's that but it might be, who knows.

 

[shaeff]

does it cough and sputter when it reaches 2k rpm? or does it just stay there and rev smoothly?

i'm not sure if you remember, but i had this problem after i put my motor back in. it turned out to be a (brand new) clogged filter and gas line before the filter. mine coughed and sputtered, and the fuel pressure also dropped.

do you have a fuel pressure gauge? if so, watch it when you rev the motor. if the pressure drops when rpm increases, it's a fuel supply problem.

other things to check would be the AFM plug as Ian stated, TPS wouldn't stop you from reaching an upper RPM, so you can probably rule that out. if you want to check the TPS anyway, you can unplug it. you'll idle a bit high, but it should run otherwise, and rev, too.

check the timing. (base and ignition) check to see if the rotor in the CPS is alligned where it should be with the engine at TDC.

for shits and giggles, check the grounds at the back lower part of the intake manifold. when shorting out, or not properly grounded, they can cause some funky things to happen.

-shaeff

 

[Loki]

I didn't even think of that Shaeff, I remember you having those problems. It revs really slowly up and then just won't go any higher. The motor revs fine when it's just sitting there and I'm letting it idle.

How would I go about testing the AFM plug? do I just test it the way it shows in the TSRM? I'll have to find an ohmmeter to test it with.

How would I hook up a fuel pressure guage to the stock fuel system? my brother has one that he hasn't put into his Mustang yet so I can probably hook it up and see what my fuel pressure is doing.

 

[IHI-RHC7]

Loki, it revs fine in neutral?

The motor revs fine when it's just sitting there and I'm letting it idle

My guess would be a huge crack in your IC plumbing...

 

[supramike7m]

sounds similar to my problems. i can park the car pop the hood and rev it fine even idling. but when i put it under a load, even just goin down the road, she takes for ever to get any speed, and rpms just creep up. and then she just stops and sputter at 4000 rpm. let us know when you figure it out. good luck
Mike

 

[Loki]

Loki, it revs fine in neutral?

My guess would be a huge crack in your IC plumbing...

Yes, it revs fine in neutrual but under load it won't rev. I'll go look over the IC pipes and see if I can find a crack.

 

[shaeff]

as IHI said, if it'll rev while in neutral and not under load, it's probably a huge IC/piping leak.

you could disconnect the CSI from the fuel rail and stick the fuel pressure gauge there temporarily.

-shaeff

 

[Loki]

Alright, I checked my IC pipes. They look fine, I even switched it all back to stock and took out my Blitz blow off. Still not revving above 2000. When it gets up to 2000 it feels like it hits fuel cut. Well it kind of bucks and the check engine light comes on and then off, but I'm not pulling any codes.

I'll go back out and re look over the IC piping and see if I can see a big crack or something in one of the pipes.

 

[Loki]

I checked the IC pipes again, could not find anything wrong with them. If I have a big vacumn leak would it do the same thing? or no?

The car will rev past 2000rpm under load, but it just feels like it's banging off of fuel cut every 100rpm or so. It doesn't really like to rev farther then 2000 but it will.

 

[IHI-RHC7]

Check your dynamic fuel pressure.

 

[Joel W.]

There are a few things that I can think of to look at.
1) Poor timing/belt jumped a tooth.. (low compression)
2) Low fuel pressure or poor flow.
3) Plugged air filter.
4) loose CPS but I think the ecu would compensate so I doubt it's this.
5) something electrical..
6) bad gas.

 

[Loki]

Check your dynamic fuel pressure.

How do I do that?