I now have another engine fitted but?

[Ian B Walker]

I should know the answer to this but alas I don't. I hope some of the guru's here can help. My beloved LAZ 4511 has had its third engine fitted. The car runs absoultly superb but. When it gets to running temp it cuts out and will not start until it cools down again. I thought it may have been a fuel problem but I have mass's of fuel at the fuel rail when I turn the engine over. Can someone point me in the right direction. Also it ticks over at 1100 rpm, how can I lower this speed to what it should be and what should it be?

 

[zcacogp]

Idling - follow the instructions on www.clarks-garage.com , I am sure that they will help you out.

As far as the engine cutting out, who fitted the engine? If it was someone else, what is their take on it? Other than that, what are the symptoms of the cut-out? Does it cut cleanly, or splutter before cutting? Does it have to cool entirely before re-starting? How old are the electrics? Have you done any other diagnostics when it has cut-out (i.e. tested for a spark, or removed an injector to see if it is squirting?)

These things would help guide a diagnosis ...


Oli.

 

[dlknight]

Have you checked the DME relay ?

Dave K.

 

[Ian B Walker]

ORIGINAL: dlknight

Have you checked the DME relay ?

Dave K.

Err No, where would I find that.

Addition, Started this afternoon and my son informed me that it is smelling of petrol from the exhaust.

In answer to zcacogp, I fitted the engine myself. It cuts out with a couple of splutters. Yes it has to cool entirley. The electrics are all original (1984). As for diagnostics, I need my assistant to help me on this and he did not turn in for work this morning.

 

[zcacogp]

Splutters (as opposed to a clean cut) may suggest more of a fuelling issue ... so I'd be looking at the DME as well as a first call. It's a big relay in the fuse box, usually labelled pretty clearly "DME". Available for around £20 from most suppliers, but ask a fellow enthusiast if you can borrow their spare. (I'm in East London and have one you are welcome to borrow if you want it.)


Oli.

 

[Ian B Walker]

Many thanks for your kind offer Oli. I live in Lancashire so a lend is rather out of order. I have tracked one down from the person who sold me the engine. I have also asked for the D.E.E. unit too. Wont hurt to have a spare.

 

[zcacogp]

Ian,

Sounds like a good way forward. Out of interest, why did you change the last two engines? Same problem, by any chance?

If the DME isn't the answer, you are into the usual non-runner fault-finding. So, hoik out an injector and check for fuel, same with a spark plug and check for sparks. I suspect if it splutters before dying that the injector will be the way forward - i.e. no fuel. Then it's a question of why - fuel pump not doing the necessary, or a problem with the injector switching etc etc etc. I did a similar exercise recently on a friends' 928, and it turned out to be the relay which provides a common supply to all injectors had failed. Simple answer (as it was a simple failure), but a real palaver to diagnose.

Keep us posted with the results from the DME swap.


Oli.

 

[Ian B Walker]

ORIGINAL: zcacogp

Ian,

Sounds like a good way forward. Out of interest, why did you change the last two engines? Same problem, by any chance?

No the first engine blew a head and some lunatic used the worlds supply of barseal to plug it before its previous owner acquired it. The head went again and thats when my problems started. The next engine was bought in good faith, it had 5 bar oil pressure while cold but when hot had zero, oil warning light was blinding me. Informed the engine's seller of the problem (main bearings on way out) and he offered me, free of charge, this engine, 88k miles and oil pressure that is really good. Runs smooth (till hot) and has awesome poke.

 

[Ian B Walker]

At long last its back on the road. I have most of the niggles ironed out of it and only have the wiper relay to replace. Took it round the country roads near where I live and all those loved memories came flowing back.

 

[cuffn]

What was the problem in the end out of interest?

 

[peanut]

yeah don't keep us in suspense wot wossit ?[]

 

[Ian B Walker]

Its a bit of a long saga. Originally bought the car for pence (ish) [] Then blew a head, had head repaired and found that not only was the head burnt and cracked but the cylinder was erroding away. Got second engine, great oil pressure when cold (5 bar) but when hot zero bar and a blinding oil warning light. Acquired 3rd engine, fitted it and when hot it cut out and refused to start till it was cold again. Changed DME relay and Maf as it was reading low on a tester. Only the wiper relay to replace but after what I have been though, its nothing. As I said, its drives really well and brings back memories of days past when I was single, care free and reckless

 

[Ian B Walker]

Took LAZ 4511 (Otto) for a drive over the weekend. I did not want to push it as I was not sure what the engine would perform like. After a quick 600 mile drive I can truthfully say that it never missed a beat and the oil pressure remained at between 4 and 5 bar. A plus note, the first 220 miles used 5.57 gallons of fuel. Well impressed. The return journey was done with a bit of spirit. 220 miles in 3 hours 10 mins. This engine IS a gud un as they say.