Revving engine hi
Discussion
Hi everybody
I have asked about this problem before,but still not resolved.
when I start the engine ,it starts ask though I have my foot on the throttle,and then immediatlely returns to
A normal tick over ie 900 revs.
All the hoses are secure ,including the 6 mm hose at the rear of the stepper motor .i am beginning to suspect
The afm .any ideas anybody
Regards Dave
Mine used to do just that, but doesn't any more.
But I have made so many changes I am not sure which one solved it.
My TVR guy used to put restrictors in the rubber pipe that has right angle bends in it and runs from the throttle backwards and round to near the stepper. He knew it wasn't a solution, it just alleviated the problem a bit - mine was sticking at 1500-2000 rpm every time I came to a junction at speed, and on start up
In the end I was having other running issues following an engine change, AFM change, decatting etc and took the car to Mark Adams, who checked all the settings and carefully re-set the throttle position sensor amongst other things. Rob (V8 D) then changed my stepper because it was faulty when hot (stalling, couldn't hold an idle), and I havent't had the problem since. I was so busy dealing with no idle at all that the high idle issue disappeared off my radar. But I think Mark rather than Rob cured the fast idle as part of his overall re-mapping my car - I left with a 14CUX chip specifically written for my car.
Might be worth a call to Mark Adams. He's a lovely guy and what he doesn't know about the RV8 isn't worth knowing. He will happily listen and advise
But I have made so many changes I am not sure which one solved it.
My TVR guy used to put restrictors in the rubber pipe that has right angle bends in it and runs from the throttle backwards and round to near the stepper. He knew it wasn't a solution, it just alleviated the problem a bit - mine was sticking at 1500-2000 rpm every time I came to a junction at speed, and on start up
In the end I was having other running issues following an engine change, AFM change, decatting etc and took the car to Mark Adams, who checked all the settings and carefully re-set the throttle position sensor amongst other things. Rob (V8 D) then changed my stepper because it was faulty when hot (stalling, couldn't hold an idle), and I havent't had the problem since. I was so busy dealing with no idle at all that the high idle issue disappeared off my radar. But I think Mark rather than Rob cured the fast idle as part of his overall re-mapping my car - I left with a 14CUX chip specifically written for my car.
Might be worth a call to Mark Adams. He's a lovely guy and what he doesn't know about the RV8 isn't worth knowing. He will happily listen and advise
The stepper motor is wound fully open on start up on a cold engine, but it then rapidly closes to get a stable idle at around 900 rpm. If yours is sticky then it could hold the idle higher for longer, so it all may just need a clean. There are other ECU inputs that hold the idle higher like the speed input, that can be present on the TVR (with Ford gearboxes) due to poor earthing of the electronics that produces the signal. The trick of blocking off the air feed to the stepper is not a fix but a work around. You can use a plumbing 15mm gate valve (Like the ones you get to isolate water feeds to a washing machine) if you want to control the amount of air until you are happy with the idle.
That depends if its already fully retracted- it normally winds back as the ignition goes off- so it may be fully retracted already when you cycle the ignition again. You need to unplug the stepper when the car is warm and idling, then stop the engine and let it cool. Then remove the stepper, and reconnect it and cycle the ignition on / off. It should retract from its warm idle position to cold start position, but only once.
Reading the original post plus blitzracing's comment, all the OP is experiencing is standard starting. Stand next to a DB9 cold starting and you will wonder what you were worrying about.
The rest of have all suffered far worse high idles, either going on for ages after start up, or when arriving fast at junctions, or just trying to crawl in traffic. Try doing the latter in stop start traffic with the idle stuck at 2500 rpm. THAT's misery and embarrassment!
OP, your car is normal.
Starmist 400, avoid cheap imports. Better a second hand original.
The rest of have all suffered far worse high idles, either going on for ages after start up, or when arriving fast at junctions, or just trying to crawl in traffic. Try doing the latter in stop start traffic with the idle stuck at 2500 rpm. THAT's misery and embarrassment!
OP, your car is normal.
Starmist 400, avoid cheap imports. Better a second hand original.
QBee said:
Reading the original post plus blitzracing's comment, all the OP is experiencing is standard starting.
/snip
OP, your car is normal.
Starmist 400, avoid cheap imports. Better a second hand original.
+1/snip
OP, your car is normal.
Starmist 400, avoid cheap imports. Better a second hand original.
It's normal for it to rev high for 3/4 seconds or so and then come down to 900 ish as the stepper sorts out the idle.
When you turn the key off the stepper retracts (you may hear a short buzz) ready for the next start. Since the ECU doesn't know what the environmental conditions will be like on next start, it opens the stepper for maximum air to help with good cold starting.
Great info here - blitz's I believe!
http://www.rv8r.co.uk/tickover.html
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