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allerston
01-26-2009, 11:58 AM
hi everyone just wanted to know is there a hot start valve on a 1990 525 m20 engine if there is one were is it located because i having a problem starting the car when it is hot but it starts fine when it is cold .

thanx guys :D

yaofeng
01-26-2009, 12:31 PM
What is it and what does it do? Not on BMW per se but on any cars.

Dave M
01-26-2009, 01:47 PM
it is where it is when its cold bt not when it is where when it is hot as i cannot find out can someone tell where internet is good for getting answers when if you don't have time to tip lots ;)

Just being a bit cheeky. Punctuation works wonders,

Dave

tim eh?
01-26-2009, 04:43 PM
Punctuation works wonders,


%$#@ yeah!!!!!!

SO DOES CAPS LOCK IT'S JUST LIKE DRINKING JOLT COLA AND EATING A CANDY BAR aT tHE sAME tIME !!!!!!!



You can retrofit an external fuel check valve, there is one inside the fuel pump that fails and there is an (air) idle control valve in the engine compartment.
I think the cps is the culprit in my semi-hot start problems tho...

E34-520iSE
01-26-2009, 05:32 PM
Duff temperature sensor?



Shaun M

Dave M
01-26-2009, 05:45 PM
Duff temperature sensor?



Shaun M

Hey Shawn,

Both the engine and coolant temp sensors likey start providing feedback to the ECU after 'warm up'. Thus, they will not affect starting. I can remove both harnesses from my M50 without affecting starting.

Dave

E34-520iSE
01-27-2009, 05:28 AM
True enough like Dave, though I did have a similar experience when I first put my car back on the road. The M20 was 'alien' to me, even though I built the thing lol!
Anyway I was about 50 miles away from home and stopped for fuel, and when I tried to start her up again it wasn't having any of it, just cranking aimlessly. After letting it stand for about 10 minutes it fired straight up like there was nothing wrong! The car did this trick quite a few times over the next couple of weeks, so in desperation I swapped both temp sensors from an E30 engine, which solved the problem. They are still in the car now so my 'emergency' fix has lasted 5 years.
A few weeks ago my ICV totally crapped out, which meant that cold starts were VERY hard, and the cold engine was cutting power when driving, though an ebay sourced ICV soon fixed that, so hot and cold starts are bang on the money for me.

Just my tuppence worth!

ATB,

Shaun M

Bill R.
01-27-2009, 09:57 AM
info immediately and will definitey affect cold and hot start. The temp sensor essentially took the place of the old cold start valve/injector




Hey Shawn,

Both the engine and coolant temp sensors likey start providing feedback to the ECU after 'warm up'. Thus, they will not affect starting. I can remove both harnesses from my M50 without affecting starting.

Dave

Dave M
01-27-2009, 10:25 AM
info immediately and will definitey affect cold and hot start. The temp sensor essentially took the place of the old cold start valve/injector

Bill,

How do you explain my lack of starting problems with the M50? Luck?

Thanks for the clarification.

Dave