Car won't run right past three grand.. HELP?

I'm not new to VR4's, or DSM's.. in that case,

I've never had this problem before, and i tried researching it but i could not find anything..

I just got the car from a friend..When you try driving it, it takes off slow and run's like crap..
once you get going it'll start boosting up, Once you hit three grand it runs like garbage..and basically can't gas it and you'll stall out.
If you keep the car under three grand at all times you can drive it fine for the most part..

I had the ECU checked out my Terry P. His self and had the caps and stuff checked out.

i've tried a few thing's but just can't seem to figure it out!!
I really hope you guy's can help me figure it out!!

 

[Jesh]

If you know any mods done to the car that would be very helpful in diagnosing the problem.

 

Car's bone stock, except FMIC.

 

[mistaVR4]

Have you checked for any leaks in the I/C plumbing? Could be a loose coupler?

 

Yes i have, It's seem's more of a sensor or something, Now it's not even wanting to start.

 

[mistaVR4]

Is the check engine light on? Is the CAS 180* out? Plugs and wires good? Fuel pump pumping, check fuel pump relay, fuses? It's been a while since I've had a running VR4 so I may not be much help. Someone here will have a better check list for ya. Toybreaker would be a good guy to speak with.

 

[dammitjim]

Quoting black91GVR4:
Yes i have, It's seem's more of a sensor or something, Now it's not even wanting to start.



Now that it's more broken the problem might be easier to nail down. Do you have spark? Fuel? Compression?

 

Has spark, Fuel,...I haven't checked compression

 

[Terry Posten]

You may need to get it over here and we can look into this more closely.

Did you swap in the second ECU to see if that runs any better/worse?

 

[OMFGeofffff]

Maf

 

Yes terry I have.. and actually it run's SO much worse..Do i needa bring the ECU's back?

 

[Terry Posten]

Most likely it runs worse because the ECU has not had time to adjust for idle. Is it driveable?

If so, get it over to me and let's start looking at the whole car.

 

It's Def not drivable right now..i pulled plugs and wires, and i'm letting the cylinders dry out, just in case, i'm gonna try to get it running tomorrow however.

 

[gramkrakr89]

Is the volume air sensor in known working condition? Any CELs?

A quirky MAF can do exactly what you're describing and much more... if you can find a known working air sensor to swap in and see if it doesn't clear up. Make sure MAF wiring is not visibly damaged.

 

Volume air sensor? and CELs?..i don't believe i've heard those terms before..
i'll have to check the wires.

 

I don't have the scan tool for the CEL, otherwise i could find out.

 

[teet]

it likely started after a timing belt change?

there is an thin alignment plate on the crank that can go on 2 ways. Basically you can flip it over or put it on the other way. That has the crank alignment not on it. you then use to check the alignment points on the crank to make sure they line up with the cams when you change the timing belt.

if you put that plate on backwards...you will line up all your notches correctly on the crank and cams but they will not actually be correct.

The car will run barely. Just as you describe.

john

 

[yeti]

Quoting gramkrakr89:
Is the volume air sensor in known working condition? Any CELs?

A quirky MAF can do exactly what you're describing and much more... if you can find a known working air sensor to swap in and see if it doesn't clear up. Make sure MAF wiring is not visibly damaged.



its not going above 3k rpms is exactly what my Mass air flow sensor did when it was blown, If u can buy a scan tool from autozone and return it after use saying it didnt work. or use the test light method

 

[gramkrakr89]

so the engine will actually run with the crank out 180deg? I figured mistaking intake strokes for compression strokes would destroy it or something...ignition prior to compression /ubbthreads/images/graemlins/dunno.gif

^ The crank alignment disc thing looks like an important thing to double check, as it sounds like it could be done easily without noticing.
---
The volume air sensor is what measures the volume of the incoming air, which is combined with temperature and barometric pressure to calculate mass at the ECU. False signal output (or bad wiring, and so on) can cause the ECU to be confused about airflow. If the sensor is totally shot or wiring is opened, the ECU will throw a check-engine light, and will assume a bogus airflow value just to keep operating, causing all kinds of running problems. [EDIT: in my experience, this causes the engine to idle really rough/rich, and get really lean/sputtery after about 2500 rpm... telltale MAF problem]

volume air sensor = MAF sensor (Mass Air Flow sensor, which is a misnomer in the case of a DSM or GVR-4)
CEL = Check Engine Light

In short, make sure your MAF is working properly and wiring is not damaged

 

I have not changed out the timing stuff yet, until the car is in good running order, however all the marks line up right.
SO i know it's not timing.. Now MAF Sounds like the biggest issue! and i'm starting to have that feeling where it could be it.