[jonno_racing]

hey guys been haveing this issue for a while and its pissing me off..

for my computer in the zook i run a standard narva relay, to switch it on and off with signal wires from the ign etc..

when i hit the key to start her the computer isnt staying on... But this is a intermittent issue.. when first start in the morning its fine.. or if you leave it a few hours its fine... just when ever it is warm etc...

what u guys thing?? releay issue or do i need to get a solid state relay? (bloody expencive but if thats what it needs...

[Reubs]

jonno_racing wrote:

hey guys been haveing this issue for a while and its pissing me off..

for my computer in the zook i run a standard narva relay, to switch it on and off with signal wires from the ign etc..

when i hit the key to start her the computer isnt staying on... But this is a intermittent issue.. when first start in the morning its fine.. or if you leave it a few hours its fine... just when ever it is warm etc...

what u guys thing?? releay issue or do i need to get a solid state relay? (bloody expencive but if thats what it needs...

What supply have you tapped for your relay? The accessories circuit is switched with the ignition key in ACC or ON, but not START. There is a supply for the coil etc, which is switched in both START and ON, from memory it's black with white trace on a Sierra (but check for it behind the fuse panel).

This doesn't explain why your problem is intermittent though, because it'd be that way all the time.

It might be your relay is dropping out from only having about 9 or so volts applied through it's coil while the engine is cranking, or it might be your computer dropping itself out.

One solution, would be to run your computer off a second battery (you could probably get away with one that's only 10Ah) that's isolated during starting. You could also have a look at capacitors. I have a 2Farad cap powering my amp. My lights never dip in time with the bass! If you used a capacitor without a second battery, I imagine you'd also need a diode so the capacitor doesn't try to feed the rest of the system while you crank the engine.

When I run my Laptop and GPS, everything has it's own internal batteries, so starting is no problem. The inverter switches off and straight back on, without a worry to my electronics.

[Reubs]

As for the solid state relay, if I were spending money, I'd install a small SLA battery, and be done with it, rather than spend $100+ on a relay and heatsink.

[royce]

I see 3 things you need to look at

confirm power is actually dropping from teh ECU (dont most have a seperate battery and ignition feed, negating the relay?

if it is test the relay, is it dropping out IE its not switching so no power is coming from it or is the supply into pin 30 dropping out?

once you know where the power is dropping start looking back, hot start problems sound like wherever you are feeding power into pin 30 isnt up to scratch due to a bad connection or something, not a switching off issue

simple problems have simple solutions not a whole heap of fucking around adding stuff

[Hybrid]

Could it still be getting power but not enough to actually fire up the computer or trip the relay?

[jonno_racing]

Ok it is solved.. it was a relay.. i have replaced the $50 one with a $11 cheepie form supercheep and no more issue..

i have run a separate power wire for the computer and i have the relay running of both ign and start...

[steak_knife]

jonno_racing wrote:

Ok it is solved.. it was a relay.. i have replaced the $50 one with a $11 cheepie form supercheep and no more issue..

i have run a separate power wire for the computer and i have the relay running of both ign and start...

I was going to say, don't use Narva relay's on Ecu's, a bosch is cheaper from ripco (have to ask for em) than Narva & for some reason Narva don't like running Ecu's

[foonji]

I was about to say it was the relay but you discovered it.... recently had the same issue with the narva relay and chepies from supercheap, so replaced them with something else entirely different and running fine so far.

[jonno_racing]

well... its not fixed but is a whole lot better.. the computer is still cutting out....

i will chuck the multi meter on it latter today....

this is a strange one alright..