General Brava 1.2 new engine won't run

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General Brava 1.2 new engine won't run

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Help and advice desperately needed...

I picked up a nice cheap Y reg Brava 80 with fogs, alloys etc but an engine that had apparently seized at 106K miles. The owner and his garage say it did run briefly afterwards (AA started it) but would then seize again. Got a matching 31K basic Brava engine from a breakers via the internet, was assured that they checked it ran before they removed it. Both engines were the later cam- and crank sensor versions with the deeper aluminium sump section.

My local engine garage did the swap for me (changed cambelt) and it fired up first time but cut out immediately with an ECU fault code and for the last 2 weeks it hasn't got any further. They have been all over it checking for bad connections, bent ECU pins, swapping cam and crank sensors, inlet manifolds / injectors, wiring loom, fuel, cambelt etc. It's been diagnosed by 2 different autosparks who could only say that perhaps the cam timing was out and the cam and crank sensors were disagreeing and the ECU did a safety shutdown as soon as it started to avoid damage. Timing has been checked and rechecked no problem found. The car will run if they spray brake cleaner down the inlet so clearly it is a fuel shutoff issue. I am assured that the error codes are cleared but reappear each time. The garage is about to give up on it and I'll be stuck - it should have been a simple plug-and-play swap.

Was there any variation between later engines where perhaps cam / crank sensor signals would not be compatible with the ECU? I am sure I started out with an electrically sound car and a mechanically sound engine, so why woun't it run? Unfortunately my local Fiat garage woun't take it on, and the local independent specialist went bust. Would a proper Fiat diagnosis with a workshop manual get me any further? Any ideas anyone? :bang:

Bothe engines have the same 4D 46550108 code on the head casting, car no. is ZFA182000 05127122, motor no. is 188A5000, version no. is 182 BT1AA26, spares no. is 5098499
 
You say they've checked the fuel system but have they checked the fuel pressure? Stick a gauge on it and start it. That's a pretty classic symptom of fuel pressure problem of starting and immediate cut out

Also a blocked exhaust (loose baffle)- gas has got to have somewhere to go
 
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I'm pretty sure they've checked this with the rest of the fuel system, the problem sems to be that the ECU switches off immediately because it thinks there's a fault or a mismatch, I don't think it's because of low fuel pressure or something 'mechanical', it's not like it dies or splutters to a halt. The question seems to be more 'what could it be complaining about?'. Like I said, most stuff has been checked, swapped and rechecked to no avail. Everything supposedly worked before the swap, now it won't quite work all together.
 
I didn't see the fault codes but they said something like "safety shutdown" or "ignition fault", maybe it depended on which analyser was used but the garage and the error were pretty vague. I've found a local Fiat independent who will look at it and check the cam timing etc with proper tools and his analyser, hopefully it'll get to him tomorrow and he'll find something silly.

Obviously I was looking for suggestions as to what folks have found wrong in the past with similar faults, other threads mention cam/crank sensors, map sensors etc. It could be a bad earth or something. No-one has responded to other threads with a "Yippee! It was the XYZ, now it all makes sense". I know cam timing is not foolproof on these engines, that's my main hope at the moment. Personally I wouldn't suspect the ECU unless it had been steam cleaned or something daft.
 
i greatly doubt it could be cam timing, what is the chance of the old engine and the new one both having the timing out in a similar fashion causing the same problem. if anything you can rule out the engie and everything else that was changed over including any sensors attached to the engine.

i agree the crank sensor is likely, but that should show up on a diagnostic with an obvious fault code (although any diagnostic tool other than a fiat examiner can not be trusted imo)

the ecu doesnt switch off if there is a fault, there is no safety shutdown, the ecu will ignore certain sensors when they fail, substituting them with a default value (aka limp home mode), with some sensors this is not possible (e.g. crank sensor) so the engine will cut out, but the ecu will still not shut down. it will store the fault code for whatever happened at that time. if ignition is switched on the ecu is also on and ready to go unless there is a fault in the ecu.

i agree with the fuel pressure gauge suggestion, that is the only way to really know if the fuel pressure is maintaining at the correct level, and since the engine cuts out shorty after starting this is definately something to check correctly. something as simple as a damaged rubber diaphragm on the pressure regulator could be the problem, or even a blocked fuel filter, but you'd never know. you dont even know for certain if the problem is fueling or ignition yet. you must diagnose the basics first rather than rely on code readers.
 
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Thanks for the replies.

I spoke to the supplier of the engine, (continental in yorkshire), he knows the engines well and said that it's probably something simple, maybe incorrect cam timing on the new engine after the garage changed the belt, maybe problem with throttle body electronics, maybe fault code not cleared down properly etc etc. He did suspect the fuel system also, so we'll see when it gets to my new Fiat guy. Hopefully it's just down to these being slightly awkward engines in the hands of your average spanner monkey / autospark.

To cap it all off, the clutch slave cylinder has gone and dumped fluid all around the clutch plate area. Should there be a cover over the top of the clutch?
 
maybe problem with throttle body electronics, maybe fault code not cleared down properly
yes the throttle body can be a headache on this engine, but that usually causes a high erratic idle that bonces between 1500 and 400rpm or similar. you do not need to clear fault codes, it has no effect, the ecu resumes normal operation when the fault is fixed without the need to clear fault codes or reset the ecu.
 
i had exactly same problem i wired my fuel pressure regulator to live on the battery and hey presto fired and continued running,try changing the air temp and pressure regulator,i done exactly the same as you bought a bravo 1242 y reg cheap and put another lump in,mine would only fire and then cut out as well. read a previous thread start and stop. lol.(y)
 
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