New With Some SR Probs For You Guys (I Actually Have One)

[Black180]

well the guys on the other forums dont help much, i've read a lot on here and found its pretty informative. hopefully someone can become my hero and fix my problem!

Well.. my SR has never run really well. At one point it did but since they its been crappy. The main problem i have been having is when you push the gas peddle the RPMs will drop down a couple hundred RPM before "catching" and coming back up. Thats one problem

it also wont hold an idle steady, i've tried adjusting the knob between the 2 runners and i just cant get it to hold 800 when warm. It will hold for like 10min and then drop to 400! Even though it is warm the whole time... It also sounds like its missfiring and idles rough at 800.

Now my newest problem, after installing a new throttle body from a DOHC KA motor (new TPS) is that whenever i put more than 50% throttle (or go over 1psi not sure which) the engine kindof stalls (either from extreme rich or lean condition) and then starts to die. As soon as you release the pedal it kind of hesitates then the RPM jumps up (goes stoich for a second and gains power). so basically the car remains undriveable.

Couple of notes, the car has only been driven about 10km. It is all stock, and at idle runs extreamly rich with occational black smoke and soot out the tailpipe. Now when you blip the throttle at idle it is very eager to pick up before suffocating. Also my plugs, O2 and AIV plug are all BLACK.

Here is my thinking:

at high load situation, the car is getting lots of air but TOO much fuel. When you close the throttle the ECU slows the fuel and the air that is in the intake manifold enters with a bit less fuel, finally causing a stoich condition causing the engine to rev high before dropping. At idle i dont know why im getting so much fuel.

I just want to figure out what to check now for this crazy situation. Im hoping i have a boost leak from the new throttle body but im really not sure... my friends SR the hot pipe popped off on one end and he had to hold the throttle full open to keep the engine running, which is why i find it weird that it may be the same case yet reversed, i have to keep the throttle fairly closed to keep the engine running.

Thanks for the time and effort to solve my problem! sorry for the long post!

[SpeedRacer1]

Leaky injectors

Your friend should have pulled over and re installed it. The hot pipe blowing out (because of an untightened clamp) happened to me.

Idle...need new IAC? It just also naturally runs rich.

How are the other fluid levels?

Stuttering is attributed to turbo lag, though if it is happening while you are in gear at like 3000rpm then thats a different story.

Wiring can cause alot to go wrong too, hows the TPS, MAFS, O2 sensor wiring, are you absolutely they are right?

Vacuum leaks will cause the engine to die if your wiring is right.

[ItzGenX]

Hmm, many cars have this problem including NA cars. What he is describing, I have felt before in many cars. This is not turbo lag. Although I have never really contributed to fixing this same problem on many other cars and motors, I have an idea of why. I think its a combination between the TPS, MAFS, and O2 sensors. You can rule out your TPS because you replace it with a DOHC KA one. The only things left can be O2 and MAFS. The MAFS and O2 are very critical to have nice and shielded wires on. They determine the values to tell if the ecu should spit in more or less fuel. In conclusion, try a different MAFS and O2 to see if it works (also trace the wiring all the way down to the ECU to see if any of them are spliced or cut or frayed etc). Timing can be somewhat of an issue regarding this because when I have felt this symptom before in other cars, at super high revs, the problem didnt seem so severe. The first and cheapest thing to check on your checklist is to check your timing on the motor with a timing light. If that checks out fine, start looking into the rest.

[Black180]

sorry i forgot to mention i did my timing by following the S14 SR20 FSM specs, and sometimes it wouldn't want to hold timing true and would sometims change around.

Thanks for the advice i will check it out for sure!

But what i want to figure it out is why all of a sudden you cannot put the engine in a high load situation.. since it came out of nowhere!

[pampadori]

you know that the tps on us models won't plug up to the brown sr plug? you must also use the ka harness plug. the reason for this is that the signal and power wires are *barely* touching at the plug. you push the gas peddle further, more voltage has a hard time getting thru the poor conection. it cuts out. my car did this 3 years ago after putting my first sr20 in. at the time, i used a ka tps plug on the harness and the sr20 tps. they looked like they plugged up right...but the sr tps was like - - - and the ka harness was like l l li found that and swapped plugs. worked great.shaun

[Black180]

the KA one was weird, it also has 3 wires with a plug on it sticking out, we tested it and it read like the TPS should so i cut off both connectors and put them together...

[pampadori]

well, thats the only thing i have seen cause that problem of no power when gas peddle is pushed to certain point. good luck with it. keep us up to date.shaun