I just swapped a turbo engine into my na S4. The engine is from an S4 and I am using the S4 harness and ecu.

Question 1.
The car idles well, but when I try to take off from a dead stop, the throttle 'sticks' and it almost dies. If I am cruising, and the pedal moves freely, the car runs great. If I put more pressure on the pedal and I feel that it's 'stuck', it starts to buck a little. That should be the TPS, right

Question 2.
I have no Speedo and no Odometer. Is this a common problem in swaps, did I forget to plug something in, or is the VSS toast? I didn't take the gauge cluster out, so the plugs on that are fine.

 

You forgot to plug them in. There's a link to the transmission that's probably not hooked up. Mine gets loose sometimes and the speedo and odometer stop working. I just tighten it up and it starts again. Check under the drivers side by the tranny and see if it's plugged in or look it up in the fsm. Hope that helps a little.

 

I had a garage put in this new engine, so I haven't checked their work to well yet. I did the swap the first time, so I know exactly where it is. I just got it last night, so I'll check that, thanks.

 

*****The engine is from an S4 and I am using the S4 harness and ecu.********

S4 Turbo harnes or??????

What's a VSS??????? Variable Stand Still????

Does your water temperature gauge work?

IF the pedal moves freely, then what is it that feels *stuck*?

 

Vehicle Speed Sensor


Now that I think about it, my gf's car does the same thing. The throttle kinda sticks when you first step on it, making it kinda difficult to start off from a standstill. You have to almost get it dislodged from a neutral point, and once it's dislodged it's fine. It's just when you stop and have to start again is when it does it. I was gonna spray some WD-40 on all the throttle linkages and see if that helped.

 

I have a VDO Water temp gauge, I got that because the water temp on the cluster does NOT work. (worked before swap) It has S4 turbo harness.

It feels like the throttle doesn't want to go down any further. I have to step on it hard to dislodge it. Sometimes it's fine for a little while, other times it sticks again.

If I am cruising and the pedal moves freely, the car drives perfectly.
Randomly, it feels like it's going to stall, when that happens, I try to give it more throttle, but it is STUCK.

BTW, I soaked it in WD-40, but the problem didn't go away.

 

There's a good chance that the swap is not complete. The turbo harness and the non turbo harness have different wires in different places in the two connectors called FEM-01 and FEM-02.

When you say your water temp gauge does not work, that is a dead giveaway that someone didn't take care of business when doing the swap. Sorry, you can't just put a turbo Emissions harness in a non turbo and not have to rearrange wires.

The water temp does not bother me so much as the question: Did they take care of the boost sensor output wire problem? or not? IF they just put a turbo EM harness in a non turbo I guarantee you that the pin 2B, the output wire TO the ECU is showing approx battery voltage when it should be seeing less than 3vdc when not on boost. Nobody can tell me that that does not effect the running of the engine whether at idle or at speed.

The sticking cable should not be that big a problem. Have someone work the pedal while you look at the cable/linkage. Remove the intercooler for a better view. You'll find whatever it is.

I trust they ran a couple of wires for your alternator so the interior gauge is working.

 

Your the man hailers. They did pretty much take the harness and just swap it, they didn't do all that other stuff you outlined. The volt gauge in side reads about 13v.

What is the problem with the boost sensor output wire?

I just installed an apex s-afc II. The TPS reads 82% throttle when the car is off. When I turn it on and give it throttle, TPS reads 0%. Does this mean anything or is the setting off?

 

IF you mate a TURBO EM harness with a NON TURBO Front harness the boost sensor output will mate with a wire on the Front harness that comes from the METER fuse, if memory serves. That act backfeeds the boost sensor AND the ECU pin 2B with a constant 12vdc signal any time the key is to ON or better.

To fix that, the brown/red wire in the plug called X-15 needs to be cut off about three inches back from the plug and capped off.

 

The following about X-15 and X-16:

The (BrR) is coming from the boost sensor and mating with a BW wire that is going to the Meter fuse. Bad.

The (YW) is coming from the water temp sensor and mating with a ...well no wire. Not good if you want a water temp signal.

The (GB) is from the auxillary fan temp sensor and is mating with ....well no wire. No harm done if you have no aux fan.

The (BrB) is a gnd wire going to every sensor in the engine bay and is mating with a WB wire that goes to the alt relay in the CPU. Not good again since it’s putting a gnd on that relay all the time when it should not.

That’s just looking at the X-15 plug and JUST the EM half of that plug (the EM is the harness that changed the F did not).

As for the X-16:

The (LgB) is from a pwr steering switch (memory here) and is mating with a YB (forget what YB does in life. Still, it’s not right.

Then theres a (W) wire mating with a GB. Not compatible at all.

Then the (Lg knock sensor output going to .....no wire at all. Wheeeee!

That’s all I care to input on this topic. A little digging will give you the answers. This is just series four , NOT series five which is easier.

 

Well, thanks for all that. You have exceeded my expectations once again.

 

*****I just installed an apex s-afc II. The TPS reads 82% throttle when the car is off. When I turn it on and give it throttle, TPS reads 0%. Does this mean anything or is the setting off?********8

Something is wrong. It shouldn't go to zip when the throttle is wide open. It's either wired (SAFC) wrong or the tps is shot.

I don't have a SAFC connected right now, but if memory serves there is a VOLTAGE page somewhere on that outfit. Go to that Snsr Check page and see what the reading is for the tps. With a fully hot engine, the reading should be approx 1 (one) VOLT DC. As you depress the pedal all the way it will most likely go to about 4.65 vdc give or take a touch and maybe as high as 5vdc (never seen that myself). Do not have the engine running doing this so you don't get distracted.

The reading should never go to zip voltage as you do that. The TPS wire from the SAFC should be going to a green/red wire in the middle plug of the ECU on a series four car. I trust this car is series four or we've been wasting your/my time.

 

change the tps asetting in the safc where you choose what cylinder engine you have and put the arrow facing the other direction or put it to the double ** and the s4 tps is narrow banded so it reads full throttle at like 1/4 throttle of atleast mine did

 

I fixed the 'stuck' throttle. I took the intercooler off and noticed that the rod going to the throttle assembly was rubbing on that medal bracket thing that holds the wiring harness that is bolted to the bottom of the uim.

I did an ohm test on the TPS. Correct me if I am wrong, but at closed throttle, tps resistance should be 1000 and wide open should be 4000-6000. The spring on the throttle assembly had no tension, so I changed it. Now I have 1008 closed throttle and 5030 wide open.

My SAFC now reads 100% throttle when the throttle is closed and moves backwards to 0% at half throttle.

I think its the SAFC, but since I messed with the tps and installed the SAFC, the car does not idle. I have to constantly give it throttle or it stalls.

 

I changed the setting for the tps and it's working correctly now. 0% at closed and 100% around 1/4 throttle. TPS voltage is .735 vdc closed and 4.5** vdc at wide open. This should be ok, right?