S16 Rebuild

Mingus said:
Woah. That's pretty fascinating. I started reading this: https://www.brighthubengineering.co...ake-resonators-improve-volumetric-efficiency/

Looks like I'm in the hunt for one of those now, as the size/volume and neck shape is tuned to the engine.
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I should have one up in the roof original one, removed when crunched the air box and pod filter was put on since there was a 12 week wait for new airbox from France.... Never got put back on (or the brand new airbox) because I liked the induction noise too much.

No good to me now (had kept them in case I ever wanted to put the S16 back to stock) since my S16 has gone to heaven..

Tony.
 
Wintermute said:
I should have one up in the roof original one, removed when crunched the air box and pod filter was put on since there was a 12 week wait for new airbox from France.... Never got put back on (or the brand new airbox) because I liked the induction noise too much.

No good to me now (had kept them in case I ever wanted to put the S16 back to stock) since my S16 has gone to heaven..

Tony.
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Awesome - Yeah, I've rigged something makeshift up, but the original would be correct volume etc.
 
Well, things have been quiet on this thread for far too long. Final push before RWC!

Update: Started her and she fired up pretty quickly, but was blowing a lot of blue smoke. Was idling okay. I was a bit concerned but I let it get to temp. Still, blue smoke. I was pretty nervous something was amiss. Then I booted it a bit and seemed to come good, and now isn't blowing smoke. I'm not sure what it could have been, a stuck lifter or something? The head also was a bit "ticky" but seems less so now it's run for a little bit. These engines have always had a bit of ticky sound to them I feel.

Anyway, the next hurdle is to find out what's going on with the idle. If you rev it, when it drops back to idle, the RPM gets too low and wants to stall. Sometimes the ISCV (Bosch idle control valve) kicks in and saves it, and then it idles fine, but sometimes it labours and stalls (which aint nice on new bottom end bearings). I swapped out an ECU and brought it up to temp and it seemed to 'learn' and be okay, but was smelling very rich. So I tried swapping out the LAMBA sensor and then it seemed to go back to how it was, cutting out when dropping back down idle. I then unplugged the lamba and swapped the ecu back and still the same issue persisted. Now both ECU's have the issue.

So, the next steps I want to try are...
1. Reset ECU and running for 15 minutes without touching the throttle to see if the ECU learns...
2. Check all pipework to the ISCV (though I'm confident there isn't leaks)...
3. Swap the ISCV and see if that helps...
4. Check the green ECU coolant sensor - though I did test the resistance at room temp before installing and the figures were correct...

Any thoughts on trouble shooting this?

Note that this is S16 306 (XU10J4), everything has been cleaned well and is very refreshed. It's a decked head, stage 1 inlet cam, 1.9L injectors, forged pistons, so there is a bit of difference to the tune.
 
Keen to hear how you go with diagnosing the rpm dip after a rev. My 306 does this a bit, but hasn't stalled in ~10,000km. My assumption was it was just getting tired and wanted most things refeshed inside the head and block. Mine has been running rich for the last ~2,000km. My thought was to check (replace) the sensors, but perhaps the ISCV is a bit sticky?
 
Mingus said:
Note that this is S16 306 (XU10J4), everything has been cleaned well and is very refreshed. It's a decked head, stage 1 inlet cam, 1.9L injectors, forged pistons, so there is a bit of difference to the tune.
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You might need the Peugeot Sport chip, although that's probably not your idle issue. Let me if you want one, I've just made a few. Best talk to Cam85 who has just been through all this, with the same specs.
 
There's plenty of power. The POD VAC setup is working as it should and it pulls through all the RPM range.

I've done an ECU reset and it seems better. I need to do a bit more testing as I think it happens mostly when it's warm, but haven't driven enough to figure out the scenarios that elicit the problem, or if it's just still learning.

I've been driving a 'spare S16' I bought off here and the AVAC solenoid was kaput, so I replaced it, and the difference is night and day below 4500rpm - any S16 needs those pods and solenoid to run half decent.

What's the chip worth Peter?
 
Update:
- Changed the throttle position sensor TPS
- Change the idle speed control valve ISCV
- Checked for for vac leaks
- Checked and made sure Throttle plate position and throttle cable were adjusted correctly

Still, the problem exists. It dips revs too low after applying throttle and stalls or gets very close to stalling.

Any further suggestions to troubleshoot?

Last ideas are ECU temp sensor? I figure the lambda wouldn’t really have any bearing when the car is cold and the coolant is below on 70c because I think it’s designed to run rich until operating temp (according to the Bosch documentation).

I’m almost at the point of adjusting the throttle to be slightly open to idle high...
 
I'd put the old injectors back in temporarily just to confirm if it's mixture related. You'll have the chip today/tomorrow, which will help confirm it one way or the other. I know with Cam's it took a bit of mucking around but we eventually got it right. Did you contact him?
 
Mine did this also but eventually cleared after going over everything as you have done. I never worked out what it was but I would also check the VSS is working and plugged in.
Mine used to sometimes almost stall even once I was ‘happy’ with it. I believe the chip from Peter made a great deal of difference. I think it has to do with the ignition timing more that mixtures when its falling from revs to idle. Try turning the ignition on and off 20 or so times without turning on the car. This apparently can reset the ICV


Once you fit the chip you wont believe the difference in performance.

They really need a ‘tune’ which can be done on these ecus. The chip will help a lot. Theres a real hard pull from 5500-7500
 
cam85 said:
Mine did this also but eventually cleared after going over everything as you have done. I never worked out what it was but I would also check the VSS is working and plugged in.
Mine used to sometimes almost stall even once I was ‘happy’ with it. I believe the chip from Peter made a great deal of difference. I think it has to do with the ignition timing more that mixtures when its falling from revs to idle. Try turning the ignition on and off 20 or so times without turning on the car. This apparently can reset the ICV


Once you fit the chip you wont believe the difference in performance.

They really need a ‘tune’ which can be done on these ecus. The chip will help a lot. Theres a real hard pull from 5500-7500
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Where’s the vss on the s16s? Is the the plug that connects to the gearbox housing with the plastic gear that gives you your Speedo reading. When I took it out the other night to bed the brakes my Speedo was working... is this the same thing?
 
PeterT said:
I'd put the old injectors back in temporarily just to confirm if it's mixture related. You'll have the chip today/tomorrow, which will help confirm it one way or the other. I know with Cam's it took a bit of mucking around but we eventually got it right. Did you contact him?
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Yeah will get that chip ad the first port of call as soon as it comes and see what happens - that way I don’t have to mess about with fuel everywhere. Then I can go back to standard injectors if it’s still ‘nervous’ catching its breath on idle.
 
cam85 said:
Mine did this also but eventually cleared after going over everything as you have done. I never worked out what it was but I would also check the VSS is working and plugged in.
Mine used to sometimes almost stall even once I was ‘happy’ with it. I believe the chip from Peter made a great deal of difference. I think it has to do with the ignition timing more that mixtures when its falling from revs to idle. Try turning the ignition on and off 20 or so times without turning on the car. This apparently can reset the ICV


Once you fit the chip you wont believe the difference in performance.

They really need a ‘tune’ which can be done on these ecus. The chip will help a lot. Theres a real hard pull from 5500-7500
Click to expand...
As in, take it to a tuner and put it on a dyno? You can program these ecus?
 
That behaviour is more typical of an engine losing vacuum, as it returns to idle. The increase in CR and later inlet valve closing, would have cancelled each other out, in that respect. Having an idle richer than 14.7:1 now is not going to hurt it. If anything, it should be happier. I'd be double checking for any chances of a vacuum leak. Do you have a vacuum gauge handy?
 
PeterT said:
That behaviour is more typical of an engine losing vacuum, as it returns to idle. The increase in CR and later inlet valve closing, would have cancelled each other out, in that respect. Having an idle richer than 14.7:1 now is not going to hurt it. If anything, it should be happier. I'd be double checking for any chances of a vacuum leak. Do you have a vacuum gauge handy?
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I don’t have a vac gauge, but happy to buy one. Will pick one up now. Chip just arrived.

Will head to the workshop now and install.

The only thing that’s changed in terms of air is the evap purge solenoid thingy that pulses the “fuel fumes” into the throttle body unit - this has been blanked off. Its minor, and is often closed anyway. The reason it was taken off was it was pulling charcoal (from the canister under the drivers side quarter panel ) straight into the inlet. I realised this once I pulled it out to test the solenoid worked and pieces of charcoal poured out. The ecu has recorded this as error code for not being plugged in 34).

Where would I check the vac pressure?
 
Plug in anywhere direct to the aluminium part of the manifold, with a tee if needed. I can't really recall all the vacuum take-off points.
 
Okay. So you guessed it Cam.... THE VSS was the culprit after all.

Put a different VSS in and it stopped stalling. Still the ICV had to catch it and pump it a bit, but at least it wasn't cutting out (still running on the original ECU).

Then I put in the chipped ECU and it improved again - Bonza!

Haven't had a chance to really drive it since it doesn't have rego, but the sport chip seems to make it sound throatier and downright mean :cool:

Rego booked in Thursday. Hopefully no rejections/objections. New rotors plus DS2500 pads and barely bedded brakes makes me a bit nervous. Haven't had any experience with these pads, do they take a bit of warming up before they bite well - might have to explain that?

I'll try get some pics/vids up soon - the paint is a bit ordinary though - needs a polish and ultimately a respray.

Thanks for all your help thus far guys/gals!
 
Excellent work. I run DS2500 on the rear of my 205. They'll be fine. Good initial bite.
 
Next little gremlin...

Once the engine gets warm, the little black pod diaphragms that open the inlet butterflies aren't moving and I'm getting the 3-4Krpm flat spot, so my guess is the solenoid doesn't like heat, or something else is at play RE vacuum, or ECU, or voltage, so open to suggestions. The weird thing is it's mounted on the firewall and not the head, so it should be cooler than usual.

The pods work when cold, and the car pulls well. I'm planning on taking the solenoid off when it's warm and testing with a battery to see if the valve opens. I'm not sure if you can refurb it because it looks pretty well sealed from first impressions - will see.

Any thoughts?
 
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