engine cranks over normally but wont start-cold

funmx5 · Postby **funmx5** » Sat Feb 16, 2013 7:23 am

anyone had this on na 1.6 ,im suspecting coil pack or ecu ,fuel pump has been replaced ,seems to be after car is wash and due morning early

gslender · Postby **gslender** » Sat Feb 16, 2013 8:11 am

Can be a few things....can you better describe the no start... Ie does it crank and crank, catch, stall, crank again, splutter, splutter, and slowly rev upwards? Or does it crank and catch fine fine and then stall soon after?

G

93_Clubman · Postby **93_Clubman** » Sat Feb 16, 2013 11:12 am

So it's an intermittent issue that seems to coincide with dewy early mornings or following car wash - is the vehicle parked outside uncovered overnight?

Did you check for the 'black wire' issue as suggested here:
viewtopic.php?f=29&t=54963

93_Clubman · Postby **93_Clubman** » Sat Feb 16, 2013 11:40 am

FWIW, just checked the Rod's Enthusiast's Shop Manual Troubleshooting section:
Engine cranks normally, but doesn't start:
Damp sparkplug leads;
Dampness in sparkplug wells;
Sparkplugs in poor condition;
Fuel, ignition or control system malfunction (establish that plugs are sparking & fuel is reaching engine);
Very low engine compression;
Blocked exhaust; &
No fuel.

Also checked the Haynes Troubleshooting section but it doesn't really add anymore value.

funmx5 · Postby **funmx5** » Sat Feb 16, 2013 1:23 pm

strong cranking no start I let it sit for 30 min ,went back 30 min later started first go ,drove it home

funmx5 · Postby **funmx5** » Sat Feb 16, 2013 1:35 pm

Ive got a factory workshop manual if was hot fault id go for a crank angle sensor ,but ive started now starts first go ,93 clubman I went back to a stock fuel pump from mx5 mania driveable is good ,now just this cold intermittant fault

gslender · Postby **gslender** » Sat Feb 16, 2013 4:33 pm

could be the temp sensor thinking the engine is hot and needing very little fuel, or something whereby extra fuel occurs only after starting the 2nd time??

Postby **Okibi** » Sat Feb 16, 2013 4:46 pm

There's a green relay in the engine bay of NAs that can play up, I think it's for the fuel pump. This may jog someone's memory and they'll tell you what I mean :oops:

Could try and pull each one by one, clean with some non residue electronic cleaner and put a tiny bit of dielectric grease on the metal spades to make sure they're making a decent contact when put back in. Do this one by one so you don't mix them up.

93_Clubman · Postby **93_Clubman** » Sat Feb 16, 2013 5:15 pm

Okibi wrote:There's a green relay in the engine bay of NAs that can play up, I think it's for the fuel pump. This may jog someone's memory and they'll tell you what I mean

That's the black 'Fuel Inj' relay in NA, or green EGI relay in NB, in engine fuse/relay box. There was a Mazda TSB for the NA6 Fuel Inj relay in the early '90s, it was intermittent & it was also cold start related, but it wouldn't crank at all. If you turned the ignition off then on again it was fine. But it's worth checking. There's also a very similar fuel pump relay under the dash.

funmx5 wrote:93 clubman I went back to a stock fuel pump from mx5 mania driveable is good, now just this cold intermittant fault

ok, but returning to the OEM fuel pump won't fix 'black wire', if it's the problem. 'Black wire' affects the inside connector & plug at the top of the fuel gauge sensor/fuel pump assembly: viewtopic.php?f=55&t=46425

KevGoat · Postby **KevGoat** » Sat Feb 16, 2013 9:37 pm

Same problem but slightly different circumstances because my engine was still warm, but this may still be relevant and worth checking. We'd stopped after a decent couple hours driving. When we went to start again, the car would crank over but just wouldn't fire. Ended up I had to have my NA trucked home by the RAA. The RAA mechanic who attended told me it was an ECU issue, but it turned out to simply be a faulty connection in the loom plug at the back of the ignition switch. Just a slight movement of the plug and the car started without a problem!

My son's commodore has been playing up badly every morning for months trying to start when cold. Same issue, cranks but won't fire. Other day it wouldn't start at all so it gave us a good chance to finally find the issue. Turned out to be the fuel pump relay! Just changed it over with another relay in the box with the same specs and starts and runs better than it has for ages!!

funmx5 · Postby **funmx5** » Sat Feb 16, 2013 10:46 pm

ep 2 tonight went to visit parents tonight guess what car wouldn't start in there drive way ,reversed car in on slight incline ,tried several times to start it then pushed car over incline second go car started humid night so no water around ,so I think fuel pump relay and wiring plus fuel filter replacement ....

funmx5 · Postby **funmx5** » Sat Feb 23, 2013 11:49 pm

still going with this one ,tried a fuel pressure reg out of bg astina ,slightly higher psi at idle ,let it sit for 40 min to 1 hr pressure has dropped ,can prime fuel up by using f/p and ground in diagonostic plug when fault occurs, its got me stuffed at the movement.......

funmx5 · Postby **funmx5** » Sun Feb 24, 2013 1:53 pm

after going over fuel pump wiring and fuel pump itself ,I tried priming fuel pump with diagonis plug it wouldn't prime ,I have track down the relay near the brake pedal once you wiggle it around gues what it primes the fuel pump .....so I will let it sit for a while to set it up again see what happens