S14 intermittent running issue

Hi All,

Got an S14 as a project recently and all has been going well... I have done the following modifications :

FMIC
Stage 1 HDEV Chip
Manual Boost Controller
Walbro 255 pump

After installing all these mods the car was running fine a 1bar boost although it did still overfuel a little, the real issues have started after a week or so!

I got in the car to go to work one morning and turned the igniton on and i heard a clicking down near my accelerator, didnt think much of it at the time as the car started fine. I then drove to work and parked up and turned the car off.

Came back out at the end of the day and it wouldnt start, just had the same clicking noise but this time it wasnt going away, the engine would turn over but not fire. Had to wait for the rac who didnt come until the next morning, i walked out put the key in and it started although it wasnt running right (limp mode) i drove it back to my farm with the rac following me and it was overfuelling a lot.

I noted that when the check engine light didnt come on with the ignition the car wouldnt start so i knew when it was and wasn't going to start.

So next me and a friend checked the following:

Checked all relays were working behind ecu and by accelerator pedal. All working fine however the fuel pump relay would either click like mad or not at all.

Hard wired fuel pump in the rear with relay and direct connection to relocated boot battery. All working can hear pump.

Checked all fuses in footwell and bay. All working.

Took ecu apart and checked solder connections on board. All look good.

Checked loom leaving the ecu all seemed fine, now this is when it gets odd. I moved the loom a bit in the passneger footwell and all of a sudden everything clicks and the car starts and works for 4 mins and then the check light came on and it started running bad again. Turned the car off and same thing again fuel pump relay clicking and car not starting.

We checked all the loom wires and cannot see a break and also checked the ones in the drivers arch.

By the end of the night the relay wasnt clicking but the electric fan would come on while cranking...

Next morning im back scratching my head.. Clean ecu terminals again and the car works leave it running for half hour all seems good, put everything back together and it's working fine. Used it for around 50miles and then the next night leaving my road it cuts out, it starts back up and driving it down the road the check light comes back on and its in limp mode again!

So im lost, if it was the ecu it wouldnt work full stop? What else can i do? Could it be an immobiliser? It has nats 2 i think.

If you got this far thanks for reading! Help please!

Sam

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Hi Sam,

It could be that one of the relays is breaking the circuit as soon as it gets hot. I had a Rover 216 which would start and run for about 5 mins then cut out. Turned out to be a knackered fuel pump relay. Did you hard wire the pump without a relay or with a new one?

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Hi mate,

Thanks for replying, we havent changed it but did check that it worked but i will change it and try. We did hard wire it but not permanently to a switch as the check light wouldnt come on with ignition so i knew it wouldn't start.

The whole check engine light not coming on with the ignition when the problem occurs makes me think its ecu related?

Cheers
Sam

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Where abouts are you? Maybe someone would be kind enough to swap ECUs for a bit?

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Quote:

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Originally Posted by knotty121

Hi All,

Got an S14 as a project recently and all has been going well... I have done the following modifications :

FMIC
Stage 1 HDEV Chip
Manual Boost Controller
Walbro 255 pump

After installing all these mods the car was running fine a 1bar boost although it did still overfuel a little, the real issues have started after a week or so!

I got in the car to go to work one morning and turned the igniton on and i heard a clicking down near my accelerator, didnt think much of it at the time as the car started fine. I then drove to work and parked up and turned the car off.

Came back out at the end of the day and it wouldnt start, just had the same clicking noise but this time it wasnt going away, the engine would turn over but not fire. Had to wait for the rac who didnt come until the next morning, i walked out put the key in and it started although it wasnt running right (limp mode) i drove it back to my farm with the rac following me and it was overfuelling a lot.

I noted that when the check engine light didnt come on with the ignition the car wouldnt start so i knew when it was and wasn't going to start.

So next me and a friend checked the following:

Checked all relays were working behind ecu and by accelerator pedal. All working fine however the fuel pump relay would either click like mad or not at all.

Hard wired fuel pump in the rear with relay and direct connection to relocated boot battery. All working can hear pump.

Checked all fuses in footwell and bay. All working.

Took ecu apart and checked solder connections on board. All look good.

Checked loom leaving the ecu all seemed fine, now this is when it gets odd. I moved the loom a bit in the passneger footwell and all of a sudden everything clicks and the car starts and works for 4 mins and then the check light came on and it started running bad again. Turned the car off and same thing again fuel pump relay clicking and car not starting.

We checked all the loom wires and cannot see a break and also checked the ones in the drivers arch.

By the end of the night the relay wasnt clicking but the electric fan would come on while cranking...

Next morning im back scratching my head.. Clean ecu terminals again and the car works leave it running for half hour all seems good, put everything back together and it's working fine. Used it for around 50miles and then the next night leaving my road it cuts out, it starts back up and driving it down the road the check light comes back on and its in limp mode again!

So im lost, if it was the ecu it wouldnt work full stop? What else can i do? Could it be an immobiliser? It has nats 2 i think.

If you got this far thanks for reading! Help please!

Sam

Sent from my VTR-L09 using Tapatalk

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This is to do with the ECU , had the same issue after I fitted a stage 1 Hdev chip into my mates ecu , exactly what your describing , best thing to do is pull the ecu apart again and move the jumper back over to the standard map until you can get it to Horsham . Did you solder the daughter board in yourself ???



I fitted a stage 1a chip in my car without a problem,
but the stage 1 in my mates just would not run properly . No idea why as I can solder pretty well .


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