Air Fuel Ratio Problem
- Thread starter bracpan
- Start date
P
pulsarboby
Guest
not true jon
the rotor arm distributes the spark to each lead in turn so if its out of sync even by a little bit it will cause no end of ignition problems
i.e backfiring, overfuelling or detting, flatspots and eventually the car simly will not start
the rotor arm distributes the spark to each lead in turn so if its out of sync even by a little bit it will cause no end of ignition problems
i.e backfiring, overfuelling or detting, flatspots and eventually the car simly will not start
red reading
Active Member
Bob the ign coil is told when to spark by the ecu, as long as the rotor arm is in the right quadrant of the dizzy cap the ecu decides when the spark occurs on that cylinder, therefor the rotor arm has to be a long way out to cause problems.
Is that why the arm is that crescent shape; it gives you so many degrees of freedom in which the ECU can send the trigger to the distributor?
If that's the case, I can see what you mean; you'd need the base timing to be about ±20 degrees out for it to miss the signal.
If that's the case, I can see what you mean; you'd need the base timing to be about ±20 degrees out for it to miss the signal.
I went up to Indigo-GT and they had a good look over it did fuel pressure tests etc and all was ok... strange thing was when you first dida run it seems fine, then I asked him to do it again and there it was running lean through out the run,,,,we were all a bit baffled so he said he would try and remap it to get around the problem and for starters dropped my old map back in and hey presto it was more or less back to normal...( I have the print out of the last map and that was perfect throught the range too) it did take a few tweaks to get it right but it was much better, we then took it out for a run and its much better still a touch leaner than before but reading ok. I went to the event and although the car was running good my times were crap...i had to drive the wheels off the thing to get a time 2 seconds slower then my best,,,,the trap times seemed ok so unless I have forgoton to drive I think my tyres and now truly shaged as they were spinning up very easy out of corners etc , but I cant thank and recomend Indigo-GT enough for there help...
Whytie yes I would like to borrow a Z32 MAF some time just to see if it dose make a differenace, they said the same at in Indigo if we I could try one to see, as there is definatly something changing on the car from time to time, I big thanks again for everybodies advice, input and help i was all very much appreciated.
Now I better start saving for new tyres for 2013,,,
Whytie yes I would like to borrow a Z32 MAF some time just to see if it dose make a differenace, they said the same at in Indigo if we I could try one to see, as there is definatly something changing on the car from time to time, I big thanks again for everybodies advice, input and help i was all very much appreciated.
Now I better start saving for new tyres for 2013,,,
Last edited:
red reading
Active Member
Phil have you change the breather system that is pulling air thru the oil separator before the maf I pointed out to you at Prescott ?
P
pulsarboby
Guest
that certainly wasnt the case with the uk sunny i got dan
the grubscrew had come out and the thing was backfiring quite badly. when i removed the cap it must have been around 10mm out which was enough to cause a major ign prob.
other ive seen that have spun simply will not start, but guess as you say it depend how much its out
Dan
No I am still running that how it is as it has no splits and works on the same principle as the standard unit, I have gone through all the hoses and so far no splits or leaks to speak of.....just took it out tonight and its still running fine, I did have a small concern about smoke on start up but its always done that and its goes away quickly. I think i will borrow a MAF just to see and go from there I am not changing anything else or Ill be back on the rolling road again,,,I now have all the power I need just need it to stay the same and then im back working on the handling and grip for next year thats were im losing out to the GT3...I can out excelerate him but cant get around the corners as quick...yet!!
No I am still running that how it is as it has no splits and works on the same principle as the standard unit, I have gone through all the hoses and so far no splits or leaks to speak of.....just took it out tonight and its still running fine, I did have a small concern about smoke on start up but its always done that and its goes away quickly. I think i will borrow a MAF just to see and go from there I am not changing anything else or Ill be back on the rolling road again,,,I now have all the power I need just need it to stay the same and then im back working on the handling and grip for next year thats were im losing out to the GT3...I can out excelerate him but cant get around the corners as quick...yet!!
Phil what ECU are you running?
On the PowerFC I had a problem where the bolt holding the CAS to the reference disk was a little lose causing the ECU to lose sync with the timing. The car sounded like it was hitting a rev limiter rather than running lean so is a different problem to yours.
MAF sounds like a sensible place to start. Also check your ECU Earth on the manifold and the condition of your signal wires from the ECU to the MAF for resistance that might effect the signal.
Just ideas, good luck with your trouble shooting.
On the PowerFC I had a problem where the bolt holding the CAS to the reference disk was a little lose causing the ECU to lose sync with the timing. The car sounded like it was hitting a rev limiter rather than running lean so is a different problem to yours.
MAF sounds like a sensible place to start. Also check your ECU Earth on the manifold and the condition of your signal wires from the ECU to the MAF for resistance that might effect the signal.
Just ideas, good luck with your trouble shooting.