Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: cush on April 30, 2012, 09:20:24 AM

Title: need some help again hot start
Post by: cush on April 30, 2012, 09:20:24 AM
Hi lately my fd3s on stock twins is struggling to start when hot. It starts first time when cold and warms up fine etc.

When i stop somewhere to get fuel etc i try to start it hot and it just turns over tries to fire and if i leave it turning over for about 10 seconds and pumping the throttle it starts up and then runs fine again.

i have done a compression test and it all came back fine with good readings i have only done 1000 miles since the last rebuild and has only just started happening.

Only other thing to add the battery is a dry cell battery located in the boot and it has started happening since that didnt know if a bad earth could stop it from starting hot does it use more power to start when hot?

Thanks all.
Title: need some help again hot start
Post by: davehg on April 30, 2012, 11:19:54 AM
Out of interest what were the results of the comp test and was it done using a rotary tester
Title: need some help again hot start
Post by: ad4m1 on April 30, 2012, 11:29:00 AM
Agreed. Also how fast does your starter motor spin the engine
Title: need some help again hot start
Post by: davehg on April 30, 2012, 11:31:40 AM
A rotary tester will give an exact compression value for each face and give you the engine crank speed as well.
Title: need some help again hot start
Post by: cush on April 30, 2012, 11:37:41 AM
That\'s a good point it wasn\'t a rotary tester a normal one make shift. Can\'t remember the results i remember they were nearly 100 think it was about 98 and one was a little lower. Where can i get a proper rotary tester from.

Thanks for the replies guys.
Title: need some help again hot start
Post by: ad4m1 on April 30, 2012, 12:08:56 PM
Proper Mazda tester is lot of money. Best option apart from spending loads is get to a specialist or call out jit
Title: need some help again hot start
Post by: amt-automotive on April 30, 2012, 12:39:43 PM
Definatley jump it connected to a good power source and compare crank speed to another car before getting to involved,
 
sometimes a hot starter cranks slower then a cold one so maybe compare the two,
unfortunately hot start is one of the most common signs of low comp,sticky seal or something,have you given it a hardish run?
Title: need some help again hot start
Post by: cush on April 30, 2012, 01:30:15 PM
Haven\'t given it a thrashing for a while now. Its all apart at min so going to get fuel injectors tested then sort battery out give it a test and if still no hope will get a proper test done
Title: need some help again hot start
Post by: amt-automotive on April 30, 2012, 02:11:36 PM
may just be a sticky seal then mate,when its back together open it up n a longish drive you may find it clears it.
Title: need some help again hot start
Post by: adib on April 30, 2012, 09:20:19 PM
hi cush not seen you on here for a while,
Title: need some help again hot start
Post by: cush on April 30, 2012, 09:51:21 PM
Hi mate i haven\'t been on for a while. Bought a house so the car had to come of the road but now its time to try and get it running well and back on the road as i miss it. How are you
Title: need some help again hot start
Post by: adib on April 30, 2012, 11:29:12 PM
im good m8, my rex got hard to start when hot and then just before xmas it went bang so its on drive dead at moment
Title: need some help again hot start
Post by: amt-automotive on May 01, 2012, 09:27:35 AM
Wonder what percentage of fd`s are dead on drive compared to those on the road.
Title: need some help again hot start
Post by: gibby250983 on May 02, 2012, 10:51:43 AM
Hay fokes mine is the same!!! Not had a re-build yet so hoping its not that!!! Just putting her back on the road for the summer!! So think she might need a good thrashing and changing the plugs might help!!

Just out of curiosity what size of battery is best!! I\'m thinking that the one I got give ain\'t strong enough!! Where is the best place to buy one!!??
Title: need some help again hot start
Post by: JayDee on May 02, 2012, 11:14:58 AM
Are these cars on pfc or standard ecu? It could be crank settings, I also have a compression tester if one is needed.
Title: need some help again hot start
Post by: gibby250983 on May 02, 2012, 11:23:32 AM
Standard ecu for mine!!! Dose start eventually but I really hope it\'s a spark problem!!! Starts good cold tho!!! Confused.com
Title: need some help again hot start
Post by: cush on May 02, 2012, 01:11:51 PM
I also have standard ecumenical. And starts perfect cold also its annoying
Title: need some help again hot start
Post by: cush on May 02, 2012, 01:13:01 PM
Bloody phones and predictive text. Ecu not ecumenical.
Title: need some help again hot start
Post by: gibby250983 on May 02, 2012, 09:14:31 PM
Quote from: cush;821900I also have standard ecumenical. And starts perfect cold also its annoying

Lol predictive text is quite funny tho!!! Lol it\'s really annouying when warm or been running for a while!! Changing the plugs and that tomorrow so see if that helps!!