C20XE high idle and cutting out

[Ems]

The C20XE in my Manta idles at around 1500rpm at idle.  Diagnostics are clear.

On my drive home the car cut out about 6 times, there's also a clicking from the drivers side fuse box area.  I can't feel any relays clicking, could it be the fuel relay under the bonnet?  The ecu is on the passenger side so it can't be that.

Thanks

[yellowhusaberg]

The idle problem might be the idle control valve,they gum up over time and then fail to idle properly.you can try to clean them with brake cleaner but it's not that good,been there and done it on my 16v.better off getting a new one.

[robah]

Does it restart easily after it cuts out?

I only ask as I had a faulty earth from the fuel pump and it was intermittent to start. I ended up slaving in a new earth from the pump to chassis.

[Ems]

It happened when I was doing 50-60mph, about 6 times - ignition light came on for a second so I accelerated and the lights went out.  All happened within the last couple of minutes of the journey. 

When I got home I let it idle (1500 rpm) - every time I touch the throttle I can hear what sounds like a relay click, I don't think it's any of the ones around the fuse box or the throttle cable/linkage making the noise.

[garymanc]

when i had injection on mine did similar and was fuel pump relay 

[taylorblue5]

The coolant temp sensors are a nightmare also on xe's so couldn't hurt to try that.

[Ems]

I've changed the coolant sensor as it was idling at 1800rpm (now 1500rpm) but the original was blue and the replacement was black - does anyone know if there's a difference other than the colour of the plastic?

Thanks again.

[Snowy]

Pretty sure one is for air-con equipped cars and one for none air-con equipped cars.

[Ems]

Quick update, changed the fuel pump relay as suggested and it has stopped cutting out. 

Thanks

[Ems]

Took the car for a 30 mile drive today, and the idle is around 1800rpm hot or cold, there are no fault codes.  Looks like I'll have to change the idle control valve.

[Ems]

It's cutting out again under load, any other suggestions?

No fault codes showing, over the last couple of months it's had new plugs, leads, distributor with new cap and rotor arm, reconditioned injectors, coolant sensor, crank sensor, fuel pump relay and new filters.  Should change the idle control valve this weekend weather permitting!

[®evo03]

Also running a xe injection!

I am in the process of curing sameish problem, word of warning fuel relay may heat up, after said amount of driving or time and break down internally, cure! buy an original gm unfortunately. 

Fuel pressure, fitting a gauge to rail, if it stops, intermittent pump or relay, you can tell, without much hassle.

Also fuel pressure reg, fitted to injection rail, could be worth asking andy if available new, aftermarket adjustable version is available, but its pricey. Gauge will suss this out

Keep us informed on your progress......

But it is hard to trace, make sure your switched ign to coil wire is sound.

Possible coil breakdown.

[garymanc]

hopefully it will be solved with your new idle control valve, also I had to change my fuel pump relay several times

now ditched injection and gone to R1 carbs, as I was sick to death getting gremlins every few months

[taylorblue5]

Xe's are a nightmare when they start developing issues. Check all your vacuum hoses and make sure there is no leaks. Clean the airflow meter gently with some carb cleaner also.

[Ems]

It's getting worse.  Last weekend I drove the car for about 5 minutes, it cut out and wouldn't restart - I even tried a new fuel pump relay.  The car came back on the back of a recovery truck! 

Prior to the breakdown I fitted a new ICV and it ran fine other than still having a high idle.  A couple of weeks ago it started cutting out and taking a while before it would re-start, this happened several times - there were no fault codes.

A couple of nights ago I fitted a new coil, but it still wouldn't start.  This morning I fitted new plugs as the old ones were sooty and had done 140 miles! 

The car started and I let it idle for a while and checked the fault codes which were clear.  I then switched off the engine and left it for a couple of minutes.  It started again and I left it idle and after about 5 - 10 minutes the car cut out.  This time it won't restart.

Checked the codes again and it says the hall sensor on my new dizzy has failed, also the body of the dizzy gets quite hot - I guess this is normal as it's attached to the head.

Any suggestions would be helpful as I'm rapidly getting fed up with the car!

Thanks again.

[®evo03]

Could it be the fuel pump, try testing it! Either on or off the car, 

[Ems]

There's power going to the fuel pump and it make a noise, there's also a pressure build up at the fuel rail as fuel squirts over the rocker if you press the valve.

[®evo03]

Could be the wiring to dissy, not the dissy it self,

Well you can eleminate fuel pump if you have pressure, even when it cuts out, and messes about,

Im thinking........

[Ems]

Still refusing to start!

[®evo03]

They are fairly basic engines, if its not fuel, it could be spark, check your switched ignition wire running to the xe loom! 

These looms are well past their expected life, especially an engine loom, would you consider a rewire, complete, or try a different loom.

Only three sensors affect ignition, crank sensor, cam sensor, and temp sensor. Your gonna need goodluck with your mission. Or a match!

[Ems]

A match is out of the question, might have to sell it instead!

Thinking about it, the engine just turns over with no hint of wanting to start.  Can the crank sensor fail without giving fault codes?

 

[Volksdevil]

On 4/16/2016 at 0:43 PM, Ems said:

Checked the codes again and it says the hall sensor on my new dizzy has failed

Did you check this further? Your symptoms of the car stopping dead, then refusing to start etc would point towards a hall sensor issue. They can break down and cause intermittent starting, or just fail completely. It 'could' possibly be causing the idle issue too, as your ignition timing may be fluctuating if bits inside have moved/broken.

Maybe worth asking anybody if they have a spare dizzy to try?

[Ems]

Car starting again, changed the ECU for another one and I left it idle for 30 minutes.  The revs dropped a few times as if it was going to stall, but they picked up again.  Now there are no fault codes!

Still idling at around 1300rpm when cold and 1800rpm when hot, can't find an air leak so might adjust the linkage.

Might risk taking it for a drive later, hopefully I'll return without a breakdown truck!

 

[Snowy]

Before you adjust the linkage just disconnect the throttle cable and see if the idle drops to normal.

If it doesn't you're getting air from somewhere? 

[Ems]

Thank you for all the suggestions.  There's free play in the cable.  I've tried finding a leak, the throttle body to manifold and powercap have been re-sealed.  I'll continue with my quest during the week.