hot start probs 944

Guest · Jul 29, 2007

Hello everyone

i acquired a 944 1984 model recently and well, i have a slight problem with Hot starts... ( i can see some people frowning lol )

basically, i drove to london ( 20 miles ) parked it, visited my friend, and then couldn't start. So we pushed the car and it started no problem. Got home, parked the car, fan cooled the engine for 10mn. Then tried to start , nothing. Waited 20 minutes, started first go...

I've read some threads but Im confused... ( starter ? electronics ? fuel pump ...? ) ( battery is charged obviously )

if someone as an answer, it will be greately appreciated.

thanks

pjb.

zcacogp · Jul 30, 2007

More information needed. When you say it 'didn't start', what didn't happen? The starter motor didn't crank the engine? The engine cranked but didn't fire? It fired, but not enough to get it going?

Also, you say you pushed it - presumably you push(jump)-started it, rather than pushing it the 20 miles home? Did this cause it to start easily and crisply, or were you chugging along for some time before it got its act together?

Oli.

Guest · Jul 30, 2007

thank you for your interest in my problems and taking time to look, i really appreciate

: right here it goes Olie:

when we pushed it, only a couple of feet , in second gear, it started fine. a few seconds before, it wouldn't: when i turned the ignition, it cranked but sounded like a dead battery... I heard the starter do it's best but no luck.

yes, when we pushed it, it started very easily.

then I drove home, an other 20 miles, no problems, runs like a clock at traffic lights and in traffic too. but when I got home, i turned it off. let the fan do its job , the fan blew for about 10 mn. After that tried to start again, no luck, just like before...waited 30mn : no problem.

A friend of mine suggested to change spark plugs: i checked the spacing of them: apparently it should be 0.60 mm, I measured 1mm. ( he reckons the engine heat makes the space biggger on the spark plugs therefor no luck in starting hot ) ( he's not an expert, just a mate )

My only worry, is that it seems to heat up easily in traffic( i have to keep my distances from the cars in front, lika in formula 1 LOl, in order to maintain an ok temp: in ther middle of the gauge ) is that normal ? Once it even went almost all the way to the right, the very hot side )

would poor quality of Oil ( old ) affetc the cooling, by too much friction ?

thanks again

PJ

Guest · Jul 30, 2007

a part from that, I love the car, the handling, the driving position, the shape, the silence of the drive. What outrages me is the price of wheel caps... damn ...

an other thing I find bizarre: the boot seems to have a motor to operate the opening but no switch in the car (motor in boott, beside spare wheel )
. I believe porsche gave uup on that system but why did they l.eave the motor ( that is something I read on a tech file on the web )

pjb

zcacogp · Jul 30, 2007

So, it cranked but sounded like a flat battery, and wouldn't start? A bump start meant it started very readily?

Sounds like a classic case of a dead battery. It won't turn the engine over quick enough to make it fire. Bear in mind that if it is struggling to crank the car, it is unlikely to be producing enough juice to fire the spark plugs at the same time.

A diagnostic would be to try and jump start it. Jump leads and another car - if this works, you have successfully diagnosed a flat battery.

Plug gaps need to be right, but won't affect this.

Boot release button (switch) is on the right hand side of the drivers' footwell.

Oli.

Guest · Jul 30, 2007

thanks very much Oli,

I don't want to be a pain but:

if battery dead, ( although it indicates 13 on gauge ) why does it start when cold ? or warmish, but not hot ?

all electrical equipments work fine including pop up lights etc

im asking cause im no expert and I want to learn, not cause I doubt

thanks a lot.

pjb

this starting problem only happens when ive driven for a longish distance, and heat hhas built up.

zcacogp · Jul 30, 2007

Ah. OK. Sorry. Missed that salient point.

In which case, it is either fuel starvation or electrical problems. The fact that it bump starts OK when hot may suggest electrical problems ... something like a bad connection to the starter motor? Electrics often are OK when cold, but their resistance goes up when they get hot so they don't work so well.

Oli.

Guest · Jul 30, 2007

ok, thanks then, i'll keep looking.

OH and no wonder i couldn't find the boot switch, the idiot that owned the car before me, as taken it out ( right old mess ). as u said, right hand side of feet space, driver side, there is a place for it, but empty...

thanks.

pjb

On your car, where does the temperature needle stay when you drive ? ( promise last question and then i ll stop harassing u ) as it ever been to the very hot area, ie right hand side of the temperature reader 0

zcacogp · Jul 30, 2007

PJB,

Starting problem - the symptoms sound familiar. Have a hunt on here - I think that someone else had a similar problem recently. Sorry I can't help more. But you are into classic fault diagnosis - Do you have a spark? If not, why not? Do you have fuel? If not, why not? Go from there ...

Mine is an '89 S2, so a fairly different car to yours in many ways. The temperature gauge has never got over 1/2 way up, and usually sits on the lower line (1/3 of the way up). But, as I said, it is a very different situation.

Oli.

Guest · Jul 30, 2007

waow ! 89 s2, that's a lovely model, and pretty swift too !

mmm, the only classic cars i had before where beetles... a good old flat4 ... that ran out of oil and blew up between cannes and Nice...

anyway, id love my temperature reading to be like yours... ive posted another topic, hopefully i'll et some positive feedback

thanks for all your help,

pjb

Fen · Jul 30, 2007

I was going to suggest bad connection to the starter or possible a bad engine earth or something - both exacerbated by heat of course.

pjb your car is an early dash model so most people won't be able to help with things like normal temperature gauge placement.

In terms of running hot have you felt the radiator to make sure it's warm all over - could be blocked. Similarly there could be air in the system somewhere.

xenon · Jul 30, 2007

Mine's an S2 too and the temp never goes very much above the first bar. I don't know if your model has the two speed fans or not - possibly only running at slower speed?

Usually hot start problems are to do with fuel starvation through evaporation / vapour lock in the fuel lines but if it bump-started OK it's probably not that. Could be low fuel pressure from a pump that's about to expire or something simple like a partially blocked fuel filter.

Good Luck.

Guest · Jul 30, 2007

If you've had beetles before then you should be familiar with their habit of the sticking starter motor when the engine gets hot- maybe your starter is on the way out and the heat from the engine is causing it to stick

northo · Jul 31, 2007

I am having similar problems with my 91 S2. Have had all connections etc checked and they seem to be fine. Car was running fine after the check, but has since once, and only once, not restarted when hot. Definately not the battery, as it is new, and the car has just been serviced, so I don't think it is the fuel filter. Very frustratiing and wierd.

Someone has suggested that I get a new DME relay. Coyuld that be the problem?

xenon · Jul 31, 2007

Could be DME relay but I can't really see it being temperature sensitive. It is easy to override the DME relay (link pins 87, 87b to 30 on the relay base) and see if it makes a difference.

Guest · Jul 31, 2007

Thanks for all the replies, v helpfull.

Well, i guess i'll just have to get use to wait 20 mn after a very long drive... As it bump starts perfect, i guess i wont worry to much... for now, until something obvious turns up. ( I have seen a wire close to the engine block, and the plastic around it is worn out... I can also see the electrical wire inside, so i'll change that )

I'll keep in mind fuel pump, but as I said earlier, It does sound like an electrical problem, as when that prob occurs, the car sounds like it's got a dead battery... i can hear the starter, i can hear the engine trrying to start, but as i said, it sounds like the battery was dead. wait 20mn and it's all fine.

oh well, thanks anyway.
pjb

Fen · Jul 31, 2007

I'd check and clean the connections to the starter and the earths (and replace that dodgy sounding wire with the bare core!) and take it from there. If it bump starts easily (which is pushing it and popping the clutch in gear as opposed to jump starts which is with leads in my terminology) then it's to do with the starter IMO. Does it jump start when it won't start itself (i.e. does adding more battery juice overcome the problem)?

944Turbo · Jul 31, 2007

Should the lux have a heat shield around the starter motor? (the turbo does) if so is it present?
Tony

Guest · Jul 31, 2007

Thanks for that Fen

I'll check my starter connectors and clean tehm, and change that worn out wire.

When it was hot, unfortunately I didn't try the Jump start ( with leads ) I only tried the bump start ( push )

Some1 mentioned resistance of wires increases with temp, so hopefully it'll be that bare wire...

Battery reading is 13, on voltmeter.

thanks indeed

pjb