OK I posted a previous thread regaring my car wasnt starting once it heated up. The conclusion from that was a f**cked PTU. So I have replaced it with a second hand series 1 from Nad. I started it for the first time in about 4 weeks which was a bit stuttery and chuggy. But when she heated up she was running perfectly. I thought it was great until I stopped at the petrol station, filled her up with optimax just to find that she wasnt going to start.

 

So I put the alarm off and on to cancel that as a problem, but when I restarted again, with a bit of throttle it came on. So I drove home and intentionally stopped the engine while nipping in to test it when I got out. Would not start for love nor money, it does turn over but doesnt ignite.

 

Anybody got any ideas of what it could be. I had been running about in the car for about 1 hour before stopping the car and if this PTU was gone too it hould have cut it on me before that right??

 

Thanks in advance,

 

Dave G

...engine only needs 2 things, petrol and a spark. So start with the easy one, remove a plug, connect it up and turn engine over - if you've a spark, you are halfway there, and if not, ...could be the PTU? If you have a spark then it's lack of fuel. Easiest starting point is checking that fuel is getting to the cylinders - not done it myself but can you disconnect a fuel line and check it's pumping fuel when the ignition's on - taking all of the necessary precautions so that you dont finish up incinerated... If you've no fuel, fuses are the first thing to check, then the pump, then the air intake heated wire thingy - lost the name in my head - sorry.

 

And if you've fuel (at the right pressure) and a (good) spark, and it still wont start, surrender.

 

Good luck

 

Jack

Cheers Jack,

 

The spark plugs were replaced a few months ago with NGK ones with the 60k service. I have just been out to her again and started first time no prob. There is a slight problem once heated up though. The revs drop to around 600 and there is a slight threat of it cutting out. I ran with it for 20mins or so, I am going to go out again and try it, fingers crossed it works OK.

 

Dave G

Dave - are all of your electrical connections - especially the two right at the front - clean? There's some pink greas stuff used to stop battery terminals corroding that's really good - clean a terminal then a fine smudge of the grease will make a good connection and keep it clean. Highly recommend it.

 

Also it might be worth cleaning your throttle butterflys - if that's what they are called.

 

...just a thought - I had a fuel pump go in a similar manner. Ran when cold but the knackered bearing in the fuel pump started to sieze when it warmed up. The result was that the fuel pressure wasn't high enough and the fuel injectors shut down. Tell-tale was alloy grinds in the fuel filter - pointed at the failed pump.

 

Good luck

 

Jack

deffo not ptu, next thing for you is to check clean ecu temp senser & harness ,as jack mentioned check for spark & fuel ive had same problem for the past month and the things ive done so far are

NEW PLUGS,NEW ECU TEMP SENSER & HARNES PTU, CHECK ALL CONNECTION, ALSO CHECK CAS UNIT CHANGED FUEL REG & DAMPENER NEW FUEL TEMP, SENSER and after all that car still wont start and when it does start it will idle perfectly for 10/15 mins then start hesitating and cut out so im really frustrated confused & pi**ed off at the moment next things to check are fuel pump control unit & try another ecu

Over fueling when warm is not uncommon problem that causes poor restating after a shutdown, although bad connections to the temp sesnor can be a cause so can the fuel regulator too much fuel into a warm engine = flooding and no starting.

 

A fuel pressure test would confirm this or simply swap it for a new or known good one.

 

Jeff TT

When my PTU packed it in, my car cut out after like 10 minutes running, engine not fully warm, then again 2-3 times driving home it cut out and wouldnt start, when I eventually got home it cut out while I was messing about with it and wouldnt restart, I left it for 2 days, 1st turn of the key it fired up.

 

HTH

 

Cheers John Crisp

dave g i had same problem as you , well certainly same syptoms turned out i had some wires that were coroded , but i am well aware that your probs could be other faults as well ,, check ecu connectors under passenger side are all conectected properly,,and try the temp sensors as well on front water pipe in front of engine clean them up if covered in green furr also do same with ptu conectors , the loom part , !! hth

 

if not contact traders mechanics , mickey b mark zen garage , jeff tt and others !

I will have a go with all of the above. I think that it is something like a connection problem or similiar as it is only happening now and again. Its iritating as its cross my finger time every time I restart her. But it starts 4 out of 5 times.

 

Overfueling also sounds a possibility, there is quite a bit of blackih smoke coming out the zorts. I have put my newly upgraded ECU in from Andy P in the past month (100 miles) and I was sure to put it back in correctly. The only thing that I am unsure which is correct is near the brake booster hoses there is a sender unit and two little other units (like my technical talk - I think it is something to do with the boost hoses for the guage). I was replacing the hoses to blue ones from smithy and broke a piece of one of the little units. So I went in the house, fixed the unit and when getting back to the car, I totally forgot how to replace the hoses. I thought what I done was correct but unure. Anyone got any pictures of the set-up (if you can figure out what I am talking about)??

 

Thanks for the help guys, I will let you know how I get on.

 

Dave G

OK after giving her a good run I had a wee look through the engine bay. Spotted a hose had came off from the top end of the drivers side dump valve. Must have came off a couple of weeks ago. Funny thing was it was still in the car and sitting next to the fan, i dont know how it wasnt lost.

 

Anyway, car is running perfectly again. Do you think that this was the problem due to balancing or something??

 

Dave G

Had same problem with the other-halfs, relieve pressure on fuel filter and it would start no problem. Fuel regulator seemed to be the problem, eased the bolts holdind the item , a couple of spoon fulls of fuel spurted back !! and hey presto, it started. The JOY of owning a Z.