Car seems to hit a brick wall

[Schmuckingham]

Ive got a 91 AWD auto with a freshly swapped manual engine and ECU in the car. Now when i first got the car it had a blown engine in it and i swapped out for the mnaual one. I got it running and then put the manual ECU in. Other day i changed my tranny fluid and filter cause it was slipping a little. Changed it and it was fine til the other day i rolled into a bit half throttle and it spooled fine until half way in the RPMS it hit like a brick wall, stopped pulling and then jerked back into pulling again. Only does it half throllte on the move not full throttle.

This car is basically stock except the swap, K&N, and a Greddy Type S which i added when i did the fluid and filter change. Only thing i can think of is a few things:

Fluid is too high( bu i checked and it seems fine)
TPS
Filter doesnt sit low enough
BOV opening

Any idears?

 

[Schmuckingham]

Anyone?

 

[oldman]

Are you venting the bov? I would start with a boost leak test.

 

[xcz504d]

Alright, lets try this loically because you didnt give much information.

What's happening? Car stops accelerating instantly and feels like you hit a wall. Does it feel the same as if you came off the throttle without it up shifting? or does it feel harder than that like you hit fuel cut? Is your check engine light on?

When is it happening? Mid RPM? During a shift? Always at the same exact RPM? always the same exact gear? When you come off the throttle during boost at a certain RPM? What was your boost level at? Did your boost spike or drop?

 

[Schmuckingham]

The car just stops moving, like its hitting rev limiter but its just for a moment and it begins to pull again. I dont have an aftermarket boost gauge in the car cause im selling it so the stock boost gauge doesnt move at all so it couldnt be loosing boost unless its minor enough for that shitty gauge not to read.

It does it whenever it feels like it, as long as your at least half throttle into it and making higher boost. No CEL but it has flipped on before then off just for a second but that was at idle, never moving down the road. I mean this car is basically stock so the wastegate only goes to 10 psi or so with the boost control solenoid gone.

yes the BOV is vented only because the retard before me has an intake that doesnt have the port for it to recirc back in and the car didnt even come with a recirc tube.

 

[HondaStalker]

i'd say tps, my cousin's did the same thing, but it didn't do it just at half throttle, but sometimes he could punch on it and it would hold up and pull.

 

[Schmuckingham]

See thats the thing, sometimes i could punch it hard from a stop and it would be fine, but its getting worse as i go.

So just maybe adjust the TPS?

 

[Schmuckingham]

So i yanked my boost gauge out og my Honduh and its seems to do it only when it goes above 15psi, like it will spike to 18 adn then cut out loose boost and then pull again.

I never felt fuel cut like this in my old Talon.

 

[oldman]

Are you venting the bov? I would start with a boost leak test.

A lot of fuel cut that happens when it's not suppose to are caused by boost leak, make sure you have no boost leak first.

 

[dnhieu]

did you check to see if your waste gate is connected? it sounds to me like your hitting fuel cut.

 

[Tech9Talon]

I have a similar problem and blow my low IC hose off, possible boost leak? I also hear a loud noise like a hammer hitting my motor occasionaly. I have a bad TPS too

 

[02WRX1stgenDSM]

mine also does this but it is only at full throttle and its the same Rpm every time regardless of gear or boost...5300 rpm everytime....usually run 15 psi but dropped it down to 12 ... runs fine other than this.... anyone figure this out yet... also i have a 1990 TSI

 

[bboyxtac]

http://www.vfaq.com/mods/ICtester.html


u might want to check dis out

 

[Tech9Talon]

My car runs fine now. I had a few vaccume lines disconnect *slaps forehead*. The PCV valve to intake was off, but I don't think it would cause I problem. There was another on the intake that ran towards the firewall, not sure what it went too. The pressure line to my waste gate got caught in the fans and chewed up. The lower IC pipe was leaking. And last but not least, the vac line from the FPR(and boost gauge) to the intake manifold blew off, I have not idea how? I replaced some vac lines and the car runs fien now. Might wanna check those lines.

 

[Schmuckingham]

I dont know its real weird, it will only do it sometimes and my boost spikes sometimes and its all fooked up. Im thinking it may be fuel cut because its soo damn cold here. But ill check the lines for leaks. what are autos supposed to pull vac wise at idle in park?