NB no start issue.

[melv1n]

Hi guys,

Trying to diagnose a crank no start issue with my 98 nb.
I read when the ignition is switched to on the engine light on the dash should light up to indicate the ecu has power.
Mine only lights up Seatbelt, Battery and Handbrake.


It's cranking fine but not catching, has fuel and spark ok. Fuses ok.

Cheers
Pete

[melv1n]

Interesting update.

I unplugged the fuel pump relay and then cranked it to see the difference......and it fired up for the first time in a few days.

It obviously died shortly there after but thats certainly interesting.

No idea what it means though. lol

[oozmakappa]

Interesting update.

I unplugged the fuel pump relay and then cranked it to see the difference......and it fired up for the first time in a few days.

It obviously died shortly there after but thats certainly interesting.

No idea what it means though. lol

could be your fuel pump's dead?

[manga_blue]

Interesting update.

I unplugged the fuel pump relay and then cranked it to see the difference......and it fired up for the first time in a few days.

It obviously died shortly there after but thats certainly interesting.

No idea what it means though. lol

Weird. The fuel pump is needed to supply pressure to the injectors. With the relay out there'd be zero fuel running through to the motor. Therefore to fire up there must have been fuel sitting in the inlet ports already. i.e. The motor was flooded. No idea how you can get a flooded motor with electronic injection though.

Can you repeat that? Try to start it with relay in, fuel it up, remove relay, start and run it until all fuel burnt? I don't know what it tells you but someone here might have seen it before.

[RS2000]

I read when the ignition is switched to on the engine light on the dash should light up to indicate the ecu has power.
Mine only lights up Seatbelt, Battery and Handbrake.

I could be wrong, but I don't think NB1's had an engine light - only seatbelt, alt (battery), handbrake & airbag.
Cheers

[rascal]

Weird. The fuel pump is needed to supply pressure to the injectors. With the relay out there'd be zero fuel running through to the motor. Therefore to fire up there must have been fuel sitting in the inlet ports already. i.e. The motor was flooded. No idea how you can get a flooded motor with electronic injection though.

I actually had a similar scenario at Sandown a while back. Car wouldn't start and plugs were dripping wet with fuel.
Engine cranked over at almost normal speed, and plugs would show spark when sitting on engine cover.

Turned out to be loose battery cable lead, ( )which would give enough power for spark when no compression (ie plugs out) but wouldnt fire when plugs back in.
ECU provided fuel and triggered coils as per normal but obviously not enough juice to fire COPS and it just flooded engine.

Tightened battery cable and after a few cranks with WOT for fuel cut to disperse the extra fuel, car started no problems..

[hks_kansei]

I had similar to Rascal.

Over time the battery clamps stretch and lose their grip, my car would run fine then occationally just not start (mine would lose power fully though, no crank, no lights, nothing)

I just replaced the battery terminals.

[manga_blue]

So it seems that weak power supply to the coils is the cause. I'd check for:
- weak battery (maybe try starting it with jumper leads off a car with a good battery)
- loose battery terminals
- loose or corroded earth straps (front and rear of inlet manifold, behind dipstick and rear of PPF)
- dodgy MAIN relay
- damaged coil pack wiring connectors (the wires leading into the connectors are known to be prone to failure inside the insulation)
- old spark plugs or leads. Plugs are good for 20k, good leads last 100k, bad leads much less
- corrosion where the spark plug leads connect into the coils

[melv1n]

Thanks a lot guys.

I pulled the plugs this morning and they are all fueled up.
Replaced them and no change, battery terminals seem ok and tight, certainly providing good spark to the leads.
Went to repco to replace the ignition leads and he quoted me $210.
So i think i will ring around for them.
Really appreciate that list manga, especially the earth loccations.
Will run through the list tonight.

Cheers
Pete

[hks_kansei]

$210 is well above the normal price.
In saying that, MX5 leads seem to be stupidly priced compared to other cars anyway.


From memory Supercheap do Bosch leads for about $80

I have Magnecor leads on my car, they're about 15 years old, they're discoloured and have been oil soaked, but they still work. The only issue on them is that the clippy part on lead 1 has worn, so it no longer clicks onto the plug properly

[melv1n]

One other quick question.
The ngk ignition leads for a 98 nb, RC-MZN802, come in a pack of only 2 so obviously thats for a later twin coil nb.
Any know if na8 leads would work with no issues with an nb8a?
Cant get any Bosch local, might have to order.

Thanks again

[hks_kansei]

NA8 leads work fine, as do NA6 leads.

Just make sure you attach them in the right order. I seem to remember the NA coils were mounted the opposite way around to the NB or something.

The leads are the same though, the leads on my car came directly from an NA6

[melv1n]

Damn...i pulled the fuel line off the fuel pump housing and the 2 o rings and the blue collar came out of the line as it pulled away, i.e stuck to the metal spout going to the pump one of the o rings was broken also.

Can i replace the seals inside or do i need to replace the entire line?

[melv1n]

Im talking the o rings and the spacer in this btw.
Looks like a much bigger job to replace the entire line.

[melv1n]

i will just order a replacement, not worth ahortcuts with fuel lines.