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General => The garage => Topic started by: dude on 25 February 2009, 08:00
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16 valve engine code kr.
at 1000 revs set my ignition timing at 7 degrees and goes very well chuffed no pinking !
but when i rev her up to 4600 shes advancing to 48 degrees surely this is to much,or am i doing something wrong
i have followed the haynes manual.
any ideas why this is thanks a lot.
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did you read it with the vacuum hose connected:
2 Run the engine at idling speed and note the basic ignition timing. Pull the vacuum hose from the control unit, then increase the engine speed to 4600 rpm and read off the ignition advance. Deduct the basic advance and the resultant value should be 18°, this being the advance attributable to engine speed.
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thanks.
yes did exactly all that.
so that would make my advance 41 degrees. if thats how i think it works.
ive tried another ecu. distributor. what else controls the advance curve i can look for.
thanks rub johnny.
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the ign controller is all that controlls advance, maybe the temp sensor is duff?
tbh if the car drives ok and it was the same on 2 ign controllers I wouldnt be concerned, haynes isnt known for being factually correct all the time! 16v info in particular leaves a lot to be desired. I'll see if I can dig anything up!
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I've found some info in the MK1 Bentley on the Scorcco 16v. However it only talks about CIS-E, but the 'knock sensor control unit' is very similar to our 16v ignition controller, its basically the same but with knock sensing added on. However that doesnt mean the ign settings are the same, but I would be surprised if they arn't!
RPM-dependant Timing Advance
Start the engine and let it idie for a few minutes to establish a base timing value in the knock sensor control unit. Check and record this base reading. Disconnect the vacuum hose from the knock sensor control unit. Raise engine rpm as indicated, then compare maximum timing advance with the base value:
CIS-E rpm-dependant timing advance:
total timing @ 2500 rpm = measured base timing value {4 to 8 degrees BTDC} plus aproximately 13 degrees
After this check, stop the engine and reconnect the vacuum hose to the knock sensor control unit, if timing does not advance at increased rpm as specified, the knock sensor or the control unit is at fault. See 5, Knock Sensor System.
Vacuum Advance
Check vacuun advance only after determining that the rpm-dependent timing advance is correct. Start the engine and increase engine speed to about 3400 rpm. Record the total timing. Disconnect the vacuum hose from the knock sensor control unit and again raise the engine speed to about 3400 rpm. Timing should advance approximately 6 degrees from the previous value. If not, check the vacuum hose for kinks or leaks. If the hose is OK, the knock sensor control unit may be faulty.
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A bit more detail.
the car was originally 8valve kjet done 9 years of road rallying in it and bless her she won a few.
so 3 months ago decided to put a 16valve in spent a grand on a full rebuild. done about 20 mile in it took it to a rolling road and she melted top of piston and smashed head and bottom end.Great!!!!!!!!!!!. On the rolling road she was advancing to much 40 degree plus 2 injectors were not working.
So start again, another engine. I put it in at the weeekend with a different ecu & distributor and four new injectors, very impressed with
it. But after checking the ignition timing here are the figures
1000 revs 8 degrees
2000 revs 24 degrees
3000 revs 42 degress
4000 revs 48 degrees
Ive been told thats too much advance and I dont want this one to blow!
Now then bearing in mind she started out a 8 valve kjet I had to put the 16 valve ecu and ecu loom in it, is there any wiring that
effects advance and retard that I could have forgot to put in. I dont have the throttle valve wired up, warm up regulator wired up
but I am very pleased with the performance of the engine, its just this bleeding advance problem.
Cheers for helping. I got a rally in two weeks!!!!
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sounds like she's trying ur patiance a bit dude !
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nope thats all there is, the dizzy is a dumb unit with no advance built in, no weights or vacuum. or at least it shouldn't, whats the part number on it?
advance is handled completly by the ign control unit, all the rest of the gubbins on the 16v is for idle stabilisation and cold starting
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that choudl actualy explain things if the dizzy was teh wrong one and started advanceing.
48 deg is a lot of spark and a lot more than i'd expect to see for max advance, something is really pileing in the advance between 2000 and 3000 rpm carb dizzys do do that
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i have tried 3 distributors on it and and 2 senders that the blue and white wire goes on!
got my brothers car here exactly same set up that at full advance is 32 degrees which i would think is correct.
swapped ecu and dizzy off his onto mine but still does the same.
im missing something will be on the job all weekend any more ideas greatly appreciated. thanks R J.
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hmm very odd. are the cams in the engine original KR ones?
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ye they are i just put a knew cambelt on it before i put it in.
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hmm, inter-cam timing?
oh just had a thought, whip the cam sprocket off and make sure the keyway hasnt sheared, bit of a long shot though. Fact that same happens on a setup thats fine on another car has me proper stumped :undecided:
Might be an idea to get the multimeter out and check all the wiring to the ign controller plug
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it is a confuseing one, it choudl be the ignition control unit throwing a hissy fit because somethign isn't connnected but i've set 16v's up on carbs useing it and had them running fine with bugger all connected.
dose sound like multimeter time
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thank you all.
ok this is what im doing!
strobe light hooked up pointing at fly wheel set it on 0 turn dizzy until diamond mark is in line tighten dizzy up.
now point light at crank pulley move dial on strobe to 6 degrees slots line up back to fly wheel revs up to 3000 move dial on strobe to 32 degrees diamond mark lines up. but if you go back to crank pulley its on 40 degrees what do you think of all that. cheers
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so do you take the 6 degrees away from the 32 which gives me 26 :rolleyes:
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no need to add or subtract anything it's total advance is the number that matters.
digging through some PDF's it's 6 deg with vaccume hose connected at idel hose connected, with that set, run the engine at 4600 rpm you should see 24 deg of advance from TDC or 18 degrees if subtracting the basic advance. with vaccume hose off you should see the ignition retarded 20 degrees compared to when hose connected at 4600. so 4 deg of advance from TDC
your figures now make sense if the basic timeing set with the vac hose off the basic setting will be 20 degrees further advanced than it shoudl be. so when the vac hose is reconnected an extra 20 degrees of adance appear 44 - 48 deg of advance now makes sense as take that 20 off it's be 24-28 whitch is right
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Think ive fixed it :grin:
What id done wrong, i think, was the double plug thats by the ecu thats part of the ecu 16valve loom, that has a black & yellow which is linked to the throttle valve switch and the red & yellow which is linked to the fuel pump i had going to a live & earth because I thought it was powering the ecu, thus sending the ecu into a dizzy fit, so i unpluged those two wires blanked vacum advance pipe set tickover to 10 degrees now shes fully advanced to 28 degrees at 4000. But I did have to take the battery lead off for a couple of minutes for the ecu to settle down.
So now the black & yellow red & yellow are unplugged and the ecu is getting its power from the plus on the coil.
Advance pipe blanked.
10 degree tickover 28 degree fully advanced.
Thanks RJ & Danny P for your help.
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ahhhh that could explain it. the black yellow to ECU is NOT power, thats only supposed to be live when the throttle is shut :)