ignition cutting out under load

[teh_mechanic]

Car - Eg, B16 conversion done about two years ago.

Cruising along its all fine, but if you punch it in say 2nd, the revs willl climb from say 2000 to 5000ish (different most times) and then the engine completely cuts out, gives you that dohhhhhhhhhhhhh sound as the revs drop as if you have broken your timing belt or something, then as soon as you let off the throttle and get back onto the throttle its back to fine, since your still rolling and the ignition is still on, so then it then continues along fine, until you punch it again, but even then sometimes it will repeat or sometimes it will pull clean all the way to redline.

Sometimes it does the same cutout just at vtec engagement. like - accelerate, 1/4 second of vtec scream, then cut out.....let off the throttle, back onto throttle its back to fine.

Been happening intermittently now for about a month
Distributor is only about 4 months old... ICM in it is about a year old, coil is as old as engine.

Theories - 1. Wiring isnt the best, so im thinking it could possibly be a wire rubbing as the engine shifts back under load, doesnt really explain why it does it higher in the rev range and even before vtec sometimes though. And you think this would blow one of the fuses.

2. Coil could be dying and cant take it under load, i would of thought this would just result in misfire though, not the engine dying completely but then restarting as soon as you let off the throttle.

3. ICM freaking out? though last time it died the symptoms were high rpm misfiring and tacho needle freaking out.

4. Fuel delivery issue? prob not, would prob only be misfire

5. ECU/Tuning - as it happens, i had a s100 in it, about 1 week ago it got stolen, so now i have an s300 on base map (runs shit with my mods), its due to be tuned next thursday, hence why i want to try and fix this, if im lucky it will fix itself with this new ecu. i was running that s100 tune for about a year though so no reason for it not to of been good for the last month

6. Main relay or fuel relay problem - would of thought this would totally cut the car out and it would not want to start though.

Anyone had a similar problem with a fix? apart from this the car was fine before but i cant get it to do it anymore because the s300 base tune is so bad it misses when idling cold, is rich as obviously, vtec sound comes in but not much power change and it misfires so bad at 6000 it wont go any faster....i only tried that twice, then decided it wasnt a good idea...so i cant really test the problem at the moment

[90LAN]

spark plugs fouled ?

[fat_85_civic]

mine was doing the same thing, too much throttle and it whould miss.
it was the leads, changed them and its fine
the more load on the engine the harder it is to spark, rpm doesnt matter as much

[CRXer]

sort out theory 1 before u bother to look any further

[ECU-MAN]

I have seen this with a faulty coil

but do check your main relay.

was it running fine with the S100 ?

[teh_mechanic]

had this problem when running the s100. that got stolen couple weeks ago. put a s300 on it yesterday, loaded base p30 map and it runs absolutely crap (due to type r valvetrain and all the bolt on mods i suppose) but with the couple runs i gave it (dont want to cause any damage) it didnt cut out or anything, just missed when cold and when it tried to vtec, didnt have this miss before so i think thats just a tuning issue. the cutting out was was only an intermitent problem though so it would be foolish for me to just assume this new ecu has fixed it.

i have a spare coil i was going to sell. i will put it on to try and avoid worst case scenario of paying dyno setup fee next week only to have the car playing up and being taken off dyno. will also check main relay solders, thanks for the input

with the car idling i shook the hell out of the wiring loom and it didnt seem to mind it so dont think its a shorting wire.

as for the plugs no i dont think they would be an issue, car ran fine just cut out at random points when under load. Leads will be fine, they would induce a miss not a total cut out.

Most logical problems to my knowledge would be the coil or ICM.

Hopefully this coil will fix it

thanks guys

[Limbo]

yeah i'm in the middle of sorting mine out also.
I got some werid issues at the moment and not 100% sure what it is also
At the moment i think mine is ICM also

[JasonGilholme]

i had a weird issue where my ignition would drop when under load. It wouldn't cut out completely though, just a cylinder or two.

Turned out to he be something in the dizzy (I'm assuming ICM) cause i replaced the whole thing and it works a treat now.

[Bludger]

had this problem when running the s100. that got stolen couple weeks ago. put a s300 on it yesterday, loaded base p30 map and it runs absolutely crap (due to type r valvetrain and all the bolt on mods i suppose) but with the couple runs i gave it (dont want to cause any damage) it didnt cut out or anything, just missed when cold and when it tried to vtec, didnt have this miss before so i think thats just a tuning issue. the cutting out was was only an intermitent problem though so it would be foolish for me to just assume this new ecu has fixed it.

i have a spare coil i was going to sell. i will put it on to try and avoid worst case scenario of paying dyno setup fee next week only to have the car playing up and being taken off dyno. will also check main relay solders, thanks for the input

with the car idling i shook the hell out of the wiring loom and it didnt seem to mind it so dont think its a shorting wire.

as for the plugs no i dont think they would be an issue, car ran fine just cut out at random points when under load. Leads will be fine, they would induce a miss not a total cut out.

Most logical problems to my knowledge would be the coil or ICM.

Hopefully this coil will fix it

thanks guys

you're very wrong with what you said about leads and plugs.

I've had similar problems where cylinders cut out when putting down the throttle.

one occasion it was plugs and the other, it was leads.

[teh_mechanic]

you're very wrong with what you said about leads and plugs.

I've had similar problems where cylinders cut out when putting down the throttle.

one occasion it was plugs and the other, it was leads.

yes for sure cylniders can cut out because of worn leads and plugs. this is called missing, as i stated. Because the resistance in them is too high to allow the spark to jump the gap

it shouldnt cause total shut down of all four cylinders though.

I've changed the coil and it got rid of the missing when cold and when in vtec (this miss only started since changing to the s300 with a shitty tune on it). So my conclusion is that the coil was on the way out and it was causing the total loss of ignition problem i was having... and i think the miss it sudenly got after puting the s300 on is due to there being heaps and heaps of air/fuel being poured in and the coil not having the power to combust it.

thanks for the help

[ECU-MAN]

good work

I also agree with you on the difference between the mis and cut out, two seperate issues.