Hi there guys.

Just rebuilt my engine, and now the car is running on the road.

Engine has been very good for about 800 kilometers, now sometimes when I'm at about 2000-3000 rpm, I feel this "lag" like turbo-lag, likes the supercharger is not working or something.

Anyway, if I put the pedal to the floor while this "lag", the car goes to LIMP mode, EML and SES light up and engine almost dies, I only can hold it ~1000 rpm and drive about 40-50kph.

I just switch off ignition and right back to "on", and engine goes off LIMP mode, EML light goes away but SES remains, but i still feel that supercharger-lag sometimes.

I plugged it to a laptop and got some codes that seem to be unrelated. (P1117 for example).

I've looked through some threads here and got some hints about:

- Throttle Body Sensor
- Throttle Body Plug
- Manifold Absolute Pressure Sensor

Any clues ?

 

Have recently had similar problem on my 04 MCS. 62K with no major rebuilds.

 

I'd bet money it is your crank pulley starting to seperate. Mine just went south with those same symptoms. Octaineguy has a thread that hits it spot on.

I replaced all the above parts and still threw p1618 I think was the number. Check if when your car starts the limp mode if you smell burning rubber. If you do order a new crank pulley.

 

P1117 Mass Or Volume Air Flow Circuit Low Input (Bank 2)

 

If the computer is getting bad info...it would certainly cause issues, and make the computer go into LIMP mode....

 

I think it has nothing to do with the crank pulley, does that results the belt to slip, or what is the caution that the engine looses power before the EML light goes on.

 

You got that right! But I will have to clear the codes this evening, and try to drive and get the codes again and look them up.

Any ideas greatly accepted

 

Check this thread out and see if the symptoms are the same as yours:

https://www.northamericanmotoring.com/forums/drivetrain-cooper-s/155159-p1688-limp-mode-smoke-burning-smell.html

I know I followed the computer error codes and they led me astray. The crank pulley was separating inside and was causing the belts to slip thus throwing the throttle codes.

Here's what my pulley looked like after I got it off the car.

 

Yeah i checked it out yesterday, had no smell at all.

After driving a bit more, It seems that this problem is a on/off type of problem.

I drive it a little bit and try to accelerate, I feel that it has no power so I let go off the throttle and try again, untill I feel this "CLICK", where the power snaps right back in, and the car works great until I stop on a red light or something. Where the car has to idle...

I'm thinking of Bypass valve stuck open here and there?

 

You can test the therory without spending any $$ (and inspect it) by using a ziptie to secure it closed, and then go for a test-drive....
Since your SC will be producing boost even at idle, your mpg will temporalily drop a bit...
Usually a stuck bypass valve does not throw codes....
You might have a dirty sensor/failing sensor..have tried cleaning them with some sensor safe cleaner. That, and make sure the cliP's s on the wiring is secure.

 

In my case this may very well be the cause!

This morning I started my engine (after a very cold and stormy driving the night before) and my car started but as if it where on 3 pistons, started choking, EML and SES lights turned on, engine was about 800 rpms, I shut it down and tried it again, this time it started all normal, revved a bit and all felt ok but SES stayed on, EML light remained off. By the way, I didn't noticed any burning rubber smell.

What do you guys think?

I'm gonna stop by an AutoZone to run a computer check and post the code(s).

Thanks!
RayanMX

 

Today it is pretty much all the time, that the engine feels no power at all. It seems to link with cold weather.

It is about 10°F temperature outside, so what sensor is failing, I don't know ...

 

I am sure you have looked over all connections to make sure nothing is loose. A wire can do odd things, especially the main computer connection.