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[Kevin Wood]

You Clever Man Kevin  

Ill Give that a shot in the morning Mate Thanks sooo Much such an easy way of finding out now why oh why did i not think of that

Noone has said my timing looks out in the photo so ill take that as its ok  

Thanks Again Kevin  

Craig

Let's see if it works first!

I think it's worth checking the voltage as TheBoy said. Poor voltage regulation could cause multiple errors to be reported.

Kevin

[Craig_R]

If It's an open mixer system, a weak mix will cause mire backfires funnily enough. Try half a turn at the knurled adjustment insert on the gas inlet pipe. On that note if it's a closed system and the O2 sensor has given up, this would effect the mix on the inlet pipe. Also check the airfilter isn't blown back into the bottom of the filter box, if it is you'll find the joining clips on the motorway.  If the air filter is displaced it could have an effect at the MAF sensor.  

Mine's been running rough with a us cam sensor and MAF but still running and as you say in the limp mode unwilling to rev over 4500rpm but would easily rev to the red line on gas. Changed them both today and its fine now.

I hope this helps. Merry Christmas to you and yours. Good luck in getting home.

Tony

Thanks for the input tony

But mine is a closed system and the lambda is brand new only acouple of months old, also if it was the MAF it would report a code of 0100 and
on my air filter box it has a blowback valve fitted to release pressure if there is a backfire stops the air filter box getting a hole blown in it.

Ill be checking on the voltage first before unplugging anything.

Thanks
Craig

[Kevin Wood]

Thinking this through a bit more, I think my money might be on the crank sensor, but let's see what tomorrow brings. My reasoning is as follows:

The cam sensor is normally only used to establish the phase of the engine. Since cylinders 1 and 4 and 2 and 3 have their TDC at the same crank angle, the cam sensor is required to determine which one is on its' firing stroke and which one is on its' exhaust / intake stroke. This allows the ECU to inject fuel sequentially to the appropriate cylinder. Once it has established this relationship at engine startup, it won't change, so I'd be surprised if it's even using the cam sensor. If the sensor breaks while the engine is running, I doubt you'd notice anything until you next started it.

Running on LPG with a mixer system, injector sequence is irrelevant so I would not expect it to affect the engine much at all if the sensor was broken.

The crank sensor, however, is the primary source of engine timing information and without it, the engine will try and run on the cam sensor but the timing reference is very very approximate since it gets a pulse every 2 turns of the crankshaft instead of one every few degrees of crank rotation. This means that if the engine's speed changes rapidly, the ECU can't keep up and the timing will wobble around, maybe causing a backfire with the inevitable consequences on LPG.

Kevin

[Craig_R]

Thanks Kevin that actually makes alot of sence what you said and was really helpful  

ran fine on petrol well upto 4500 rpm and rubbish on gas with backfire underload when i tried to put my foot down

[Bandit127]

I had this on a 1996 2.0 16V. Driving along, usually motorway between 50 an 70 and it would just cut out. Straight dead, like electrics not fuel. The first couple of times the rev counter went crazy, after that it just cut out.

The rev counter is driven by the crank sensor so that was my prime suspect. It did have a small air leak between the ICV and the throttle body so it could have been spark failure from overheated plugs - due to weak mixture. Still don't think it was mixture though, it went off like it was on a switch.

Traded it (told the buyer about it) before I solved it so sorry, can't help any more than that.

Oh hang on..., is yours gold, about 115k miles and faded lacquer on the boot and bonnet?
Think I'll get me coat...

Jim

P.S. Always re-stated and carried on fine after about 10 secs with no other problems.

[Dave-C]

Strange thing is, the 4 pot can run with either the cam or crank failure.  Not with both failed though! Be odd if they both failed together...

Double check the charging voltage.

 :-/

Had any dash bulbs blow lately :-?   A good indication of overcharging..

DC

[Craig_R]

Strange thing is, the 4 pot can run with either the cam or crank failure.  Not with both failed though! Be odd if they both failed together...

Double check the charging voltage.

 :-/

Had any dash bulbs blow lately :-?   A good indication of overcharging..

DC

No Bulbs Blown Dave or none that i know of but ill check, now coming to think of it i did think the dash was alittle dim the other day at night but ill wait till i check the voltae tomorrow before i know for sure

[Dave-C]

Strange thing is, the 4 pot can run with either the cam or crank failure.  Not with both failed though! Be odd if they both failed together...

Double check the charging voltage.

 :-/

Had any dash bulbs blow lately :-?   A good indication of overcharging..

DC

Could be the battery then....  that was the tell tale sign for mine 2 weeks before it gave up!!!!!

And to digress, Was talking to one of our mechanics at work...  he's done it for years!  Very experienced...  He was telling me that if a battery gets condensation or damp or wet from a puddle, that, it can short out + to gnd 0v...  he recalls that thay had a Transit in once that the battery was shorting out through the bottom of the case to the tray, that's when folks had used to put a mat on there to prevent this happening as insulation.

DC

[Dave-C]

Forgot to say, on component common to both sensors... is the ECU!...

Sorry! but it's true... Hope it's not that, obviously...

DC

[Elite Pete]

If youve had a backfire with the LPG the MAF sensor might have been damaged as it directly in the line of fire.

[Big_Mart]

If the car is limited to 4500rpm it is in safe mode it goes into the mode when it can`t detect engine rpm had this exact fault about 9 times over the years and its always traced the the crank sensor being kerfunked i do remember once that some one had put a self tapping screw in which had worked loose causing the sensor to come loose and mis read.