I will put this in cliff form for ease of reading

- Have a 2001 Mazda 626
- Had a low idle
- Removed TB and cleaned it with TB cleaner
- Cleaned the intake manifold
- Put everything back together
- Car would start but then stall instantly
- Took it for a drive by keeping revs high - engine didn't sound good
- Car would cut out every time I slowed to a crawl/stopped.
- Removed and refit the TB
- Car still won't run properly - it just starts then stalls


Any help??

 

Did you disconnect the battery followed by pressing the brake pedal (better alternative to an assistant)? Watch this video: Rough Idling Issues |*MotorWeek .
You should have cleaned the MAF as well with MAF CLeaner. Did you install a new gasket for the throttle body? Tighten everything back together? Inspect for tears or rips in the intake tube before the throttle body?
Did you remove intake plenum? ---- new gaskets for it as well!

 

Hi,

The problem turned out to be the gasket of the throttle body. It had deteriorated so I removed it, scrubbed the plate clean and following advice I read elsewhere I made my own gasket from card as a temporary measure. It worked and the car started without stalling but now I have smoke coming from my engine bay...

Is it possible that I wrecked my engine driving it with that vacuum leak? I drove it for about 10 minutes because I'd read that the ECU needed time to get used to the new clean throttle body. I was also told to rev is hard to clean out any throttle body cleaner which may have gotten into the inlet manifold.

I've disconnected my battery and will leave the car alone for now.

Am I doomed?

 

Revving it hard is less than 3,000 rpm! ECU does need re-learning provided you did procedure right by disconnecting battery before you cleaned it. When cleaning I like to catch all crap from throttle body with paper towels (remove throttle body, still sitting there though with paper towels on other side). Did you use proper fluid as per video? As long as you used proper fluid without revving too high you should be fine. The smoke may be over spray from cleaner of somehow leaked on to engine and smoking.
You should be OK. When you re-hook up battery let it idle for at least 10 minutes before driving, slowly increasing accelerator for 50 miles. Don't floor it right away!

 

Whoops. I was told to hold it at around 3000 rpm for a minute to clear any junk out. Then I drove around for 5-10 minutes and kept it in 2nd gear most of the time. I went mad with the revs and when I got home I could smell a funny smell from the exhaust. Like burnt rubber.

I forgot to say that when I was refitting the TB some coolant spilt out of one of the the pipes and onto the engine bay below it. Could the smoke be the coolant burning off?

 

yes !!!

 

Oh, I hope that was all it was

Thanks

 

I just took the car for a quick drive. It performed OK but when I returned I noticed that at idle the exhaust sounds louder now. It burbles.

The other day when I was driving the car with the vacuum leak not fixed I heard the exhaust rattle a couple of times, especially as I pulled away. Is it possible that I have rattled something loose or could I have damaged it internally by driving it with a strong vacuum leak and revving the engine hard?

 

Anything is possible. the exhaust rattling is better than the engine rattling. A worn exhaust gasket around the exhaust manifold may rattle and give you a lean code as well. Hopefully, after your stuff you spilled burns off you won't have any other smells. If you do have exhaust smells under the hood, you may have an exhaust leak.
Hopefully, it is just an exhaust shield outside the exhaust that came loose (that doesn't need to be fixed).

 

Fingers crossed.