AX running nightmare!

triumphtoledo · Post by **triumphtoledo** » 28 Apr 2006, 10:52

Hey guys! Any ideas on the following fault which is driving me nuts?

Car is a 1.0 N reg AX, with Bosch Monopoint fuel injection. 65,000 on the clock. The following problem has appeared within the last 30 miles.

When cold, the car starts and runs fine. As it warms up to normal temp, the car hesitates, loses power and "bunny hops" at any throttle opening; worse when driving round town. When a revving engine is returned to idle, the engine idles at around 1200 rpm before dropping to around 800, but sometimes "hunts"; and sometimes drops so low the engine almost stalls. If the engine is revved and held at 2,000 rpm in neutral, the engine speed drops to idle even though the throttle is applied.

If the AX is taken on a fast run to say, 60 - 70 mph with a few racing starts, the above symptoms disappear; however if the engine is switched off for more than 5 minutes, the problem reappears.

The throttle body has been taken off and cleaned with carb cleaner. The idle speed motor has been dismantled and is clean and in good condition, and the 3 electrical connections have been checked and cleaned...no difference.

I suspect the lambda sensor next...any ideas guys??

Thanks!

Rob

mezuk04 · Post by **mezuk04** » 28 Apr 2006, 11:10

My old Zx 1.4i use to do the sort of thing you describe added with stalling pretty much all the time...In the end I believe it was down to air in the fuel lines however I cant be sure (hated that car for that problem).

It would stall when braking, accelerating, when the clutch was pushed down....just anytime.

triumphtoledo · Post by **triumphtoledo** » 28 Apr 2006, 12:15

Hi! Thanks for your reply!

Would an air leak in the fuel cause this problem, except when engine is very hot or stone cold?

AndersDK · Post by **AndersDK** » 28 Apr 2006, 15:47

The Lambda sensor would not cause that kind of erratic engine running. That would be more like a steady rich running symptom.

IMHO when you have this very erratic rpm (stalling tendency) despite trying to correct with the acc pedal - then its the throttle potientiometer teasing you. Because of a worn out (a hole in the) carbon track.
If that was true the engine would also show a tendency to "ghost" reving at its own mind. I.e. may suddenly run up to 3-4000rpm for a while - and then shortly after it may stall.

If the engine does NOT do that rpm ghosting, I'd say with the symptom of yours it would be the map sensor playing up.

triumphtoledo · Post by **triumphtoledo** » 28 Apr 2006, 17:06

Have taken the throttle potientiometer off and it is inn perfect condition.

THe MAP sensor souonds like a good start! What is itr and where would it be on the AX?

Cheers Anders!

Rob

mezuk04 · Post by **mezuk04** » 02 May 2006, 10:13

Bump! Some more help required people

citronut · Post by **citronut** » 02 May 2006, 13:06

i would check all the vacum hoses if you have an air leak in the inducktion this could cause the fault you are getting
regards malcolm

triumphtoledo · Post by **triumphtoledo** » 02 May 2006, 14:52

would a coolant temperature sensor cause this roblem and if so where is it on the AX?!!

Thanks again!

mezuk04 · Post by **mezuk04** » 02 May 2006, 14:55

I'm no expert as many would agree

But I seriously doubt a temperature sensor would cause this kind of problems your having, I would investigate Anders post (location still unknown?) and I also agree with Citronuts post, an air leak would cause the problems your having also.

triumphtoledo · Post by **triumphtoledo** » 02 May 2006, 14:59

As Anders suggests, where abouts the the MAP sensor on the AX?

Help, it's raining!!

mezuk04 · Post by **mezuk04** » 03 May 2006, 08:54

Bump!

Can you not get hold of a BOL's!

Where is the MAP Sensor???

triumphtoledo · Post by **triumphtoledo** » 03 May 2006, 12:03

I have found a pipe that comes from the throttle body to the nearside rear inner wing. There is a white cylindrical unit, that almost looks like a one way valve, with a connector going to it. From there, the pipe disappears into the gap between the inner and outer wing. Is this the MAP sensor I wonder?

Sl4yer · Post by **Sl4yer** » 03 May 2006, 17:00

We've had this argument many times before on this forum!

The Monopoint ZX has no MAP sensor. Some claim to have found one, but I'm sure it doesn't. The BoL agrees.

I would expect a Monopoint AX to be the same. I think what you have found is the vapour recirculating thingy.

I would recommend that you take the car to a Bosch dealer, and get them to take a look with the car plugged into their computer. It may be that the pot is giving a dodgy signal (even though it looks OK).

James

triumphtoledo · Post by **triumphtoledo** » 03 May 2006, 20:07

UPDATE!!

Removed throttle body, replaced it with a known good throttle body...and it still does the same! Drat!

If you hold the throttle to 2500RPM when stationary, the engine stays there for about 5 secs, then drops down to tickover, when the throttle is released, the revs increase to 1,500 then back down to tickover then up again to 1500 then tickover and there it stays.

Any more suggestions before I srap the thing??!!

Thanks again!

Ian Fearn · Post by **Ian Fearn** » 03 May 2006, 21:35

I've had no end of running problems with an AX 1.1i. I replaced the ECU with one off a scrap car.

No problems since, might be worth a try as theres tons in my local scrappers.