Jump to content

405 Mi16 Restoration.


Jayden M

Recommended Posts

  • Replies 102
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

1 hour ago, SRDT said:

Dou you have the check engine light on?

Goes in and out. Always on at idle, goes off when it revs up properly. Goes on when it has trouble reving.

I know there is an exhaust leak on the headers somewhere, which is what I assumed the light was on for.

How do I read for codes on this car? it doesnt have a OBDII connector does it?

Link to comment
Share on other sites

The ECU is making adjustments to the fuel map at idle with the engine warm, it had me also worried back when i bought my mi16. if you are removing batteries often this will happen. But when you are using the car every day it's not noticeable, i've only seen it when the weather changes setting a a red light it will light up , i let it idle to finish its adjusting and is good for the next few months, if you rev it up it will come on again, also you may want to check for vacuum leaks, those engines like to leak at the intake gaskets. It's a pretty crue fuel injection system by today standards but for its day it was state of the art, i've learn lots by studying how it works. It learns ( adjusts itself) at idle, on constant throttle cruising on the highway and at full throttle. I've been surprised how much of a changed it makes after it turns it self and you can hear the sound on the intake change when cruising at wide open throttle under a heavy load, the sound gets lower( deeper), I hope this helps you and makes sense.

Link to comment
Share on other sites

Checking the code I got 52 (ECU). I always disconnect the battery after finishing drive in the peugeots. I also am switching the battery constantly between Mi16 and 505

 

the car runs pretty bad at idle, and at any temperature. compression seems ok

Link to comment
Share on other sites

If you want to tune the ECU you need to change the EPROM chip inside the case.

Stored inside this EPROM there is a bunch of code and data, the ECU will verify that it's not corrupted by using it to calculate a value called the checksum. This value is also stored inside the EPROM so as long as the two are the same it's all good.

Now when you tune the ECU you change some values like max RPM, ignition and fuel maps... so the ECU will find a new checksum but more than often the value stored inside the EPROM is still the old one.

This ECU will just light the CEL and nothing more so many tuners don't bother finding and correcting the checksum, sometimes aside from a higher redline the red light on the dash is the only thing that proves that the guy did something.

Link to comment
Share on other sites

Yeah I tried that and took the engine mount off to get some more room back there. I couldnt get to one of the bolts for hours now. So i'v given up and put everything I took off back together.

But also a bad O2 sensor reading wouldnt be stalling the engine at WOT

Still having code 52 and nothing else, I am thinking of installing a new ECU.

Link to comment
Share on other sites

The idle switch is very loud you can hear it click, just make sure you throttle cable has enough slack not to be holding the throttle body open. Loosen the two little screws turn it until it clicks, then back it just before it clicks, better loose than too tight, don't worry about the full throttle function it activates anything over 75% throttle.

Link to comment
Share on other sites

  • 2 months later...

Some Progress made on the car at last. Did a ohms test on the TPS, and something is definitely wrong with it. Will have to adjust or maybe replace on this. This sort of makes since as to when I drive the car with the TPS sensor connector unplugged, the car stumbles in the exact same way that it would with it plugged in - not enough power to rev up, unless in neutral.

Oddly the uncatalyzed exhaust smell has gone away which is great.

Link to comment
Share on other sites

  • 3 months later...

Been a while - Never did find the issue, because it will no longer even stay running. Starts up just fine, but then dies just a second or two after. Occasionally it will barely stay running at around 450 rpm. I did a bit of testing and it seems to be  Lean condition. If I spray carb cleaner into the intake it smooths out, or if I hold the air flow meter flap open a bit it will smooth out engine running. It sounds like to me it would be an intake leak, but I could not find one. I think the fuel amount is where it should be, but to much air is entering since when I get the air flow flap held in the right position the idle is pretty high (but runs smooth), which also suggests its an intake leak. Need an easier way to find intake leaks. :)

Link to comment
Share on other sites

  • 3 weeks later...

Found the issue using shop manual, and pin out box tester.
image.png.5ed395f7ae38b3ede6fc2d579c0f5249.png

No voltage during the test pictured. I have no idea where those wires are as the numbers are always worn away at this age, but I will try to test continuity of these wires. Most likely its the hardest part to get to that is actually bad. Anybody have experience with replacing an ignition switch? How much work am I getting into to replace it?

Also how is it the car still starts with no power to the ECU?(These days it only rarely even starts up, and always dies immediately)

(the shop manual bits I have only show tests - not how to remove the parts)

Thanks - Jayden

Link to comment
Share on other sites

It's not hard to remove the ignition switch as long as the lock part is operating as it should. Remove plastic covers on the steering column, turn the key on the unmarked arrow and push the small dimple to pull the whole thing out.

Link to comment
Share on other sites

  • 3 months later...

A good day today. Maybe.

Its been a few months since I last touched this thing but today I got it running again. I figured it would be best to just start over testing everything again.

I got me a good fuel pump and a 2 gallon tank to feed fuel directly from the 2 gallon tank to the fuel rail in order to bypass the chance of clogged/collapsed fuel lines. I also had me a fuel pressure gauge. Doing this got it to start right up and idle, but not perfectly... its pretty shaky engine

While idling the fuel pressure is around 39 psi, if I unplug the vacuum line from the FPR then i get around 43 psi. I believe these numbers are a little low but not immediately concerning. Then when I shut the car off it takes just a few seconds for the pressure to drop below 10 psi, and after 30-60 seconds my gauge reads no pressure. Seems like the FPR is dumping to much fuel in the return line. Also while starting the vehicle the gauge is jumping all over the place. I will replace the FPR after I do more testing tomorrow.

While the engine was idling I went to each fuel injector and unplugged the connector 1 at a time. Doing this should run it on 3 cylinders at a time and the engine should shake and sound bad. And this test seemed to work. I appear to have a very weak or completely bad cylinder because when I unplug the connector in cylinder #4 the engine does not run any worse, unlike the other 3 injectors that make the engine run much worse when I unplug them.

I tested for power at the injector connector and that is good, and I also verified spark is getting to the plug. Tomorrow I will confirm the spark plug itself is sparking, and I will pull the rail off to verify the injector is not seized. If both fuel and spark check out then I will rent a compression gauge to see how healthy that cylinder is. Turning over the engine sounds pretty smooth which is why I believe the engine is sufficiently healthy.

- Jayden M

Link to comment
Share on other sites

Well now it has gotten worse and weirder...

I start the engine and it appears to be running on at least 1 cylinder, but sometimes 2. But also the cylinder that is actually working is constantly changing, and I think because of this the engine wont rev past 700 revs. I think fuel is good because everytime I take the injectors out they are spraying nicely and are powered normally. Turning the engine over on just the starter is pretty smooth compression sound. The weirdest thing is some days (like a few days ago) the car will operate mostly normal. Really having trouble figuring this one out. Any ideas are appreciated.

The car runs really rich and has lots of carbon build up

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...