HELP Extended Cranking on start up

[bmchi]

hey guys,

I'm having intermittent issues with extended cranking when starting the 5.

It tends to be a 50/50 when starting cold, sometimes it starts normally and sometimes it take around 5 cranks to get going.

I''ve noticed it starts fine when warm and I turn it off then start it up again almost straight away. However if I leave it to sit for a few minutes then try to start it up again it almost always needs to crank more.

The car is cranking strong and the battery has just been changed to a new one so I can verify that the battery isn't the issue. I have however recently changed the fuel pump (fuelmiser) and fuel filter. Otherwise the car runs fine.

any ideas? I want to find out the problem before I just start blindly changing part over and throwing money at it.

[bruce]

Start throwing money at it.
Correct - new - battery?
Clamps done up tight and clean?
Wrong fuel pump?
Fitted incorrectly (sock thingy not clogged)?

[hks_kansei]

The ECU needs to pickup a signal from the Cam or Crank sensor in order to know where the engine is, so it can do the fuel and spark thing to start and run.

Sometimes if the car is stopped and the engine is near the reference point for each, it starts first crank.
Others it may need to do a full cycle (4 rotations) to reach the reference and know where it's at.

I wouldn't be concerned about it unless you need to crank it for a while to actually fire, or it fires and splutters for a few minutes before running.

[bmchi]

hey guys,
so the battery is 1 month old, checked the voltage too its good, there no earth leak so its not losing any either. clamps are all good on the pump, definitely the right pump and the pump filter is new and seems to be fine.

My issue is that this never used to happen with the car until I started having a few issues a month ago. it is a nb8b SP model and it shutdown while I was driving one day. still unknown to why, suspected it was the fuel pump and since then I've changed the pump and fuel filter. It runs perfectly fine just take a lot of cranks to start. it sometimes stumbles after it starts.

anyone have an idea how I can methodically check to find out the source of the issue?

so far I've checked the vacuum lines and intake system to make sure nothing is clogged up. next step to check the ignition system then check general electrical connector and sensors.

this has been going on for a few months now

[Mr Morlock]

Start off by reading HKS post. For trouble shooting get the shop manual. 93 Clubman posted where to find recently. As a guess the engine cutting out might be pointer. Fault codes may also id it.

[bruce]

SPs do like bending rods.

[93_Clubman]

Notice there's been a few issues since mid March 2016:
search.php?author_id=11996&sr=posts

13 March: engine suddenly stopped while on a round about - cranked, but wouldn't restart - lights & accessories still working;

14 March: checked battery & fuses & found spark, but no fuel & no power going to fuel pump (was the lack of power to fuel pump fully resolved?);

15 March: old fuel pump tested ok, but replaced with new generic Repco Fuel Miser (refit old pump to see effect). Accidentally left ignition on, which drained battery - jumpered battery, & cranked but wouldn't start (leaving ignition in 'on' position for long enough can burn out ignition coils);

20 March: RAC jumpered the battery to check spark, but car started when cranked - turned off, unjumpered, cranked again & restarted;

< 01 May: battery tested by Mazda, found unserviceable & replaced as still under warranty - first mention of extended cranking required for starting (when did extended cranking begin? 20 March, or immediately after the new battery was fitted, or later?);

18 May: central locking issues (is an aftermarket anti-theft device fitted?);

Following is a link to a page with a very comprehensive 'won't start guide' attached, which isn't
exactly what you want, but it's the closest I can think of at the moment & it will be covered in this guide, it's just that it will also cover some other things:
https://mx5cartalk.com/forum/viewtopic. ... 9&start=15

[bmchi]

Hi thanks 93_clubman,

For the meanwhile I've ordered a new crank sensor and hoping this is the issue as I've heard they can sometime go around this time. It should arrive today and I'll change it in over the weekend and let you know how it goes.

I'll take another look, need to get another fuel pressure tester gauge so i can see if there is a leak or pressure is dropping after the engine has stopped running.

if fuel pressure is good on start up and in between running the engine I can at least rule out the fuel system mechanics, is it possible fuel or ignition could be getting a delayed signal on start up? the fact that it is intermittent indicates an electrical issue to me. I'm just not sure how to methodically check sensors, relays, wires and connectors.

thanks for you help guys do let me know if there is anything else you guys know i can do in diagnosing this issue, its been a real ongoing issue and its driving me nuts

[93_Clubman]

You mentioned when the engine shut down issue first occurred you found no power going to fuel pump. From your posts you don't appear to have addressed the issue of why there was at the time tested no power going to the fuel pump. Don't how you tested for that &/or reached that conclusion, but you may have a poor electrical connection at the top of the tank, which is caused engine shut down & now extended cranking. If that was the problem, then changing the fuel pump will not permanently fix it.

NB8B usual suspects in approx order of frequency are:
Cam position sensor;
Crank position sensor;
EGI relay;
Fuel tank electrical connector;
Coil on plug setup;
Fuel pump; &
ECU (if water gets into passenger side floor).

[bmchi]

Thanks last time i checked the connector looked fine aesthetically, and just to be sure are we talking about the one that goes from the upper plate down to the actual pump?

how can i check this? i have a multimeter at home but dont know what i am checking for...am i just checking for continuity?

Im all for DIY and learning but i think it may be time to have an MX5 guru take a look at this....does anyone know a guy?

[93_Clubman]

last time i checked the connector looked fine aesthetically, & just to be sure are we talking about the one that goes from the upper plate down to the actual pump? Yes, but the issue is only visible on the inside tank side of the connector, & then only if you unplug the connector.

how can i check this? i have a multimeter at home but dont know what i am checking for...am i just checking for continuity? Yes, check for continuity at terminals at top outside of fuel pump assembly - there were four prongs, & from memory on the NA the two upper prongs were for the fuel pump, while the two lower prongs were for the fuel gauge sensor.
viewtopic.php?f=55&t=46425

Im all for DIY & learning but i think it may be time to have an MX5 guru take a look at this....does anyone know a guy? Location? WA? If so, Steve Lee: 0-4-1-9-5-2-0-9-8-8

[bmchi]

thanks mate your a bit of a legend!

[noobee]

in my case,the fault was intermittent,the plastic part of the connector was secure but the metal had lost its grip on the pins so give it a wiggle too.I showed you a picture in a previous reply here
viewtopic.php?f=81&t=71369#p876525
I should have put a new connector on at the time( but couldn't be arsed),just pulled the prongs out,squeezed them a little tighter,reassembled.no problem so far but its always in the back of my mind if the car ever stops again.
Mick

[noobee]

oops.truncated link!this one should work.

viewtopic.php?f=81&t=71369#p876525
and direct to my problem

viewtopic.php?f=55&t=70835
Mick