I've posted a couple times about this before, still haven't found the problem. It's an 87 base model na with a S5 TII swap. All S4 electronics except for the injectors which are S5, bypassed resistor pack. S4 TII TB, 3in straight pipe exhaust back to a can, no emissions, battery relocated to passenger side bin, using the old na harness with S4 TII ECu.

I replaced the TPS and set it to spec, checked for codes, didn't throw any, just went through and cleaned up all the grounds today, I've tried just about everything, figured Id post a vid to see if it would help.

As you can see when I first get on the throttle the whole motor shakes pretty bad, it almost sounds like it's on one rotor, then after a second it's fine. When I really get on the gas it's smooth but normal driving it's really bad, especially when it's cold.

 

Injectors hooked up correctly? Might verify by spinning the cas while seeing which ones click.

 

oh man that sounds like pinging and the hesitation could be from timing too.

id check the cas/timing (thinking its way advanced) and not run or revv it till that is verified perfect. if its one thing rotaries hate worse than a lean condition, its pinging.

 

You might verify that the ignition spark is correct too.

 

wizzurp- While the car is running? No way I'm going to hear them click.

steven- Already timed the car, it's dead on. I've been driving it like this for 8 months... Yes I'm stupid.

easy e1- Ignition spark? Is that to do with timing?

 

Wizzurp- Also, I thought that too and tried switching them around. The way I have them is the only way the car will run.

 

Seeing that you're using all S4 electronics... Do you still have the solenoid resistor plugged in?

Your particular engine originally uses high impedance, which you are using... You won't need the solenoid resistor. Not unless you use low impedance injectors.

 

I bypassed the resistor pack.

 

Make sure your Ignition is firing all 4 spark plugs. Make sure you don't have a weak spark on one plug through the rpm change.
Just something to look at and eliminate a possibility.

 

See, what you fail to understand is that... N/A's don't have a fuel pump resistor relay.

The fuel pump resistor relay... And... The solenoid resistor are two different things.

So, I don't know what you think you bypassed.

 

Ohhhh, duh. I don't know what I was thinking.. Yea I checked the spark at the coils and from the wires to the plugs. All was good.

 

This is what I am referring to (the solenoid resistor):



I am not completely sure that this is your main issue. It may be, along with other little things... Do you have this plugged in? Because I am pretty sure you don't need it.

 

Yes I bypassed the resistor pack, what you pictured.

 

How did you bypass the solenoid resistor?

THIS IS NOT THE FUEL PUMP RESISTOR RELAY.

Perhaps you don't have the solenoid resistor pack.

 

Speaking of the Fuel Pump Resistor Relay you could bypass that by jumpering the Blue/Red wire(s) to the Blue wire(s). The deal w/this relay is to increase the voltage to the fuel pump during acceleration as an example but send a lower voltage when cruising at a steady state manner. If yours is not doing this it could perhaps cause a hesitation to occur. So if you have yet to try bypassing this relay it might be prudent to do so. After it is bypassed it will supply the fuel pump with a constant 12 volts and thus remove this component from the possible causes of your problem.

 

From what everyone told me that is the resistor pack and it is what I bypassed. I cut it off and then ran all the wires together.

Where is the resistor relay? And where are the wires to bypass it? At the relay or at the fuel pump?

Thanks for the help guys.

 

Should be located under the air box near the AFM. You disconnect the plug to it and bypass the wire(s) in the disconnected plug.

 

Ok now I'm confused, that's what dwb posted a picture of right? That's what I bypassed. You guys are calling it two different things.

 

What I pictured is the resistor solenoid.

The 87' N/A you have, did not come from the factory with a fuel pump resistor relay. It is a TII thing.

 

Which is different then the fuel pump resistor relay? Satch just said it's the resistor relay. Unless that's not an air filter I see in that pic?

 

You are correct as I thought he switched from S4 turbo to another turbo but it plainly states the original car was a base model and I screwed up. Sorry to all those involved.

Does your turbo have a Boost sensor or Pressure sensor.

 

^ This is a pretty important question...

 

he has the boost sensor that matches the ecu. N332

 

If it makes you feel better, im currently dealing with the SAME exact stutter with my 87 turbo. mines all stock. it wont stutter at rpms higher than 4k.

im currently in the garage pulling my fuel pump out right now to look at the sock and the tank.

as for what that guy said about a weak spark, that could be possible. My T1 coil is odd. My timing light wont pick it up but a friends will. also it wont arc out when its unplugged and you crank. but all my others will. my spark plugs tell me it is firing tho..but i hav eno idea how strong.

ive had my injectors cleaned and flow tested and they were only 30cc under with one spraying the wrong pattern. after i go them back the stutter didnt change much. just my backfiring issue went away (straight piped exhaust. have full now.)

my friends have me checking the wirng to my primaries since it seems to only happen at rpms lower than ~3-4k. i was also suggested that i may have a dead spot in my maf. but idk.

hope you figure it out. ill keep you posted on my results aswell

 

The car should run rather well w/o the help of the trailing coil so you could disconnect yours and see if the very same problem exists.