he engine is taking time to start. This is not so in the cold mornings but seems to be more in the afternoon on a warm-hot day. Particularly if left stand for some hours. Once it starts it then starts ok second etc time.

I've got most parts in spares so I've swapped the MAF and am contemplating the fuel pressure regulator. I did change the fpr, fuel filter, fuel pump and clean the injectors before winter and it's run ok since then.

Another oddity is that the engine (in afternoon) seems to surge slightly repeatedly until it warms up.

Otherwise it runs fine.

What's the steps to take to figure it all out.

another warm afternoon. Changing the maf has made no difference. That was the easiest one to check. I suppose it's fuel or electrical. I might change leads and plugs on the weekend. Kinda doubt it's that though.

I'd check the throtle body and see if it's dirty , also check if the ISC is working.

ok, will do. I've got a rebuilt plenum/throttle body. I'll swap them over on the weekend. I think I'll do that first and leave the plugs leads till after in case.

The second gen engines, both the 4 cylinder and V6, are prone to burning exhaust valves at high mileage, especially if the engine is burning oil.

Try a compression test.

Sounds like a worthwhile thing to do Max, I've never tested the compression on the car. I'll probably buy one. I've had a look for compression tester reviews to figure out what to look for *. Any tips?

edit add * I checked a few forums where someone asked 'which tester to buy'. It seems any with a flexible hose but not too long (can cause incorrect readings) hose and 14mm thread size will do fine?

I don't understand what causes the difficult starting.

This morning (cool) the engine started straight away. Yesterday afternoon again it was warm and it took time to fire up. I expect this afternoon again it will be warm and again take time to start and tomorrow morning again it will be cool and start straight away. The constant variable appears to be the temperature of the air. On afternoons that are cool through winter it has started well. On the odd day that has been warm towards the end of winter the slow starting started.

Why?

you said fails mainly hot

is fpr a fuel pump relay ..that's about replaced or checked the whole fuel system and its still not fixed


something computerish or sensor

hard to get fault codes out of that model

try another starter relay

could a faulty crank angle thingy cause the same kind of delay ?

to check that you poor water over the cranky thing when hot
if the car starts you know

Yes, it seems related to how warm the day is (not the engine). Once it has started ok on a warm/hot day it will then start ok again for some time but after a few hours if the atmosphere is still warm it takes time to start. Once the temp is cool after dark it starts ok again. Then in the cold morning it starts fine again.


the fpr is the fuel pressure regulator.

My mind had drifted in the dirction of a faulty ecu. I'm punching in the dark here. I changed the maf becuse it has to do with air. I then thought maybe the ecu was handling its signals wrongly. As you can see I don't know what's going on and am basing my thinking on a partial understanding.

Hopefully getting this fixed will expand my knowing.

Fault codes. the check engine light is only on for a few seconds when starting so I assume there are no codes to read?

What where is the starter relay

What where is the cranky thing. If you mean ctrank angel sensor that's in the dissy?

I don't understand what causes the difficult starting.

This morning (cool) the engine started straight away. Yesterday afternoon again it was warm and it took time to fire up. I expect this afternoon again it will be warm and again take time to start and tomorrow morning again it will be cool and start straight away. The constant variable appears to be the temperature of the air. On afternoons that are cool through winter it has started well. On the odd day that has been warm towards the end of winter the slow starting started.

Why?

I don't know if this would be correct but I was thinking when cold enough there's a fast idle valve that is regulated by coolant temp which is an air bypass on the butterfly to give a fast idle for startup when cold. After that it's the ISC so my theory was when warm the fast idle bypass does little so would be ISC and whatever gap is set as a base setting on the TB. So if the TB was gummed up with oil and crud which blocks any air past the plate and the ISC was not working right I'd expect it to be hard to start and hunting a bit.

Once started what's the ide like? normal RPM, does it hold when gears are selected (auto) or A/c on? talking from long ago we had a commodore that was hard to start hot and idle was erratic hunting around. read that the TB was recommended to clean every 40 000K. opened it up and totally gunked up. had a few miles on it, cleaned it and was like new. Instant fire up and steady idle.

Sure it may something else but some basic checks and maintanace can make a big difference without replacing bits .

Once started it settles on normal rpm. Thje hunting occurs, or I notice it, in the night trip home for the first few hundred meters and then it's really subtle and a fluctuation of rpm of a couple of hundred. All the time it sound/feels smooth. No particular vibrations or engine noise that I can feel hear in the car while driving.

I did do the TB before winter and I had a look while changing the maf, seemd ok, but will change the TB on the weekend.

This : http://martybugs.net/articles/magna-stall.cgi

was posted here : http://www.aussiemagna.com/forums/showthread.php?t=106086&

Which makes me wonder whether something similar is happening.

_________


However I'll go ahead with trying some of the things suggested here first.


btw I found the strter relay on p 1003.

Someone suggested to me that it may be the petrol cap, so I swapped it . No change. However I can't KNOW if the 'new' cap is ok, so I disconnected the tube from the carbon canister to see how it is this arvo. Alas, looks like it's going to be a cool day today.

I'll just do things one at a time to eliminate possibilities. Meanwhile I'm having a spare set of injectors leak tested.


If the pressure in the tank is a suspect and the canister to tb tube disconnect is a factor I'll next change the valve between the tank and canister. If not and I've got a good set of injectors I'll swap them and if that doesn't fix it I'll swap the TB.

Dont know if this will help but.Had an ED falcon with the same problem years ago,warm temp slow to start.Sometimes had to wait until cool enough to start,sometimes.
Well,turned out to be a slight crack in an ignition circuit board.Auto electrician said when it was warm the crack would just open enough to break contact.Cold the break closed,must have been minuscule.Common problem with those falcs evidently.
I think he just blobbed on some solder,charged me 50 bucks and it never did it again.