garyo Posted April 22, 2003 Share Posted April 22, 2003 I've just run up my engine for the first time - 1.8k, ported head on standard valves, VHPD bodies, 285M cams. The engine runs on all 4 cylinders, and revs quite happly when blipped, and the car drives well with a reasonable amount of power, although I've not given it more than 1/2 throttle and not tested it much due to a crank oil seal problem. The map I've used is the steve butts sb6 vhpd map that came with the ECU. The engine doesn't idle well at all, and I can hold it at about 900rpm using my fingers on the throttle - any lower and it dies, so I don't think it's an idle valve problem. When running at 900rpm, it sounds like an american hot rod on silly cams and carbs - I've fitted the cams on standard pulleys and wonder if this quality of idle is to be expected when there are no verniers? Cheers, Gary. Link to comment Share on other sites More sharing options...
Steve-B Posted April 22, 2003 Share Posted April 22, 2003 look up V7 SLR (nigel) and compare notes. His VHPD has I think closeness to yours. I started with his old VPHD map before he upgraded and AndyMac and I are running fine on a derivitive of it now. Steve 210Bhp Sinister Version-VHPD here Link to comment Share on other sites More sharing options...
timbo Posted April 22, 2003 Share Posted April 22, 2003 If using VHPD Tbs you'll most likely have an IACV rail with an IACV. Is it working? 1st check how you have this configured in the software. You should be able to play with the valve opening on the 'live adjustments' screen when setup for manual control. see if this effects idle. Check the IACV is fully closed - turn ignition on/off a number of times. Then reset the ecu. Re. cams - I tried fitting 633 cams on the std pulleys. It was nearly spot on with the exhaust cam but the inlet cam was a mile away. One tooth movement left or right was way over the top. I erred on the side of caution & bought a set of verniers. Have you checked the timing of each cam on the std pulleys? Link to comment Share on other sites More sharing options...
garyo Posted April 22, 2003 Author Share Posted April 22, 2003 Yep I have an IACV valve and air rail... I've not played with the software too much, but I'm pretty sure it's set to 'mapped' control of the IACV. I've left the car at my Parents place where I was doing the work, as it's oil leak has made it undrivable (another story!) holding the throttle open doesn't help - I can't get it to idle at anything less than 900 rpm, and when I try it stalls itself, and even at 900rpm it's rough, so I suspect even if the IACV was fully open it would be the same I've not got a dial gauge so I can't check the cams, but I think I need to buy one along with at least one vernier Gary Link to comment Share on other sites More sharing options...
Mike Bees Posted April 22, 2003 Share Posted April 22, 2003 Have you calibrated the throttle pot? This will seriously affect the low speed idle. It's also likely that the idle settings will require some tweaking to work well with your engine spec, subtle changes in spec can have a significant effect on the fuelling requirements at idle. Mike Link to comment Share on other sites More sharing options...
garyo Posted April 22, 2003 Author Share Posted April 22, 2003 I've calibrated the throttle pot, but not played with idle fueling or any of the other settings. The closest I've got to that was sniffing the exhaust fumes for richness! Shortly after that the engine started leaking oil from the rear crank seal so I gave up. Gary Link to comment Share on other sites More sharing options...
oilyhands Posted April 23, 2003 Share Posted April 23, 2003 Gary, The idle fuelling is bound to be wrong, the cam timing is bound to be wrong and the initial butterfly position is bound to be wrong, get these right and all should be well, on TBs you should have a good idle, IACV or no. Oily Link to comment Share on other sites More sharing options...
Buda Posted April 23, 2003 Share Posted April 23, 2003 please shoot me down in flames if this is a stupid one but.. 900rpm seems a trifle low for idle speed, my 1.6KSS idles around 1000 - 1100rpm, maybe the idle speed is too low? on the standard plenum the iacv can be heard, when you turn on the ignition it whirrs and fuly opens and then closes then opens to approx 10mm (not measured it but its definatley open), if its sticking you'll hear it, mine went off on one and opened and closed with gay abandon all on its own, my new one (cheers bob) works fine, I'd take it off and have a look, other thing is check the water rail temperature sensor it could be giving silly readings to the ecu. Link to comment Share on other sites More sharing options...
Richard_E Posted April 24, 2003 Share Posted April 24, 2003 900 rpm sounds OK for a idle speed. On more extreme cams than 740 i can get mine to idel from as low as 600. Curently have it set at 900 rpm on the Emerald. Link to comment Share on other sites More sharing options...
Steve-B Posted April 24, 2003 Share Posted April 24, 2003 check and see if the green o2/temp sensor on the rearmost TB is securely fastened down. had a slightly different problem with our VHPD that came down to it having worked loose. was giving ECU false readings. screwed up idle, and gave flat spots at certain speeds. Steve 210Bhp Sinister Version-VHPD here Link to comment Share on other sites More sharing options...
Paul Ranson Posted April 24, 2003 Share Posted April 24, 2003 I think the fact that you can get a low idle doesn't mean you should. But I don't remember the engineering rationale. I'd stick to 1100 for vaguely fancy cams and solid tappets. The racing engines I've come across recently vary from 1600 to 4000. Actually the latter was 0rpm because it had no idle at all. But it made enough power at 4000 to allow you to select a gear without a stall. Paul Link to comment Share on other sites More sharing options...
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