Hello Again
Ok recently i was on here about my cossie misfire under light throttle.
I have now checked, cleaned connections,gaps, etc. The misfire is @1000
and approx 2000 under light throttle. It's at this rev range that i get what sounds like a small misfire and slight popping in/from the exhaust. Is there anything else you guys might know or is it a case in getting the car booked in at GGR etc. Any more info would much appreciated.
Thanks in advance

Graham.

 

Could this be the throttle position sensor??

Cheers

Graham.

 

HI GRAHAM, again,

Have you had the co%checked, i think last time u said stage 1 chip 15psi boost,
u say the misfire is while reving the engine while under the bonnet, could be throttle switch if tracks, are worn would do it at same revs everytime,this with
other sensors ie map, coolant temp, air temp, to calculate from ecu how much fuel needed, at idle part throttle and full load,2wd check pin 11,+30-, at ecu or on switch 400/600ohms, pin 30+17-,in idle position for test 00,if resistance measured
adjust switch,slacken 2 screws on switch and adjust till no resistance, bitch to get at otherwise replace, volts pin 30+11 ignition on T/Closed 4.5to5.5v, open throttle 0.5v.my diagram shows in throttle switch pin order 30/17/11, but on test is 11/17/30.
so u may need to do a continuity test from t/s to ecu to find the correct location for each wire counting at the ecu plug once u find pin 1 as a starting point if u take the ecu plug, apart they are written in the plug, sounds like co% T/S, MAP,OR VACUUM LEAK, good luck, what are the plugs colour,if u take idle speed control valve plug off, engine warm
what is your base idle speed,(tick over)rpm.

Dave,

 

HMM, small pops and sound slike missing/spark collapse at low revs....

what plugs are in? not champion C57's or something...? swapped mine for the proper AGPR12PP8's and it idles like a dream now - the champions are a race plug and not very good at low speed.

 

David R5
Have checked all measurements as said. All appear to be as said. Have found that throttle switch looks like it has been apart before.Found silicon around the plastic cover/body. When looking inside the switch it looks like are definate wear marks which could be around the 1k to 2k rpm possibly. Now have yhe dilema of poss changing the switch because of this and the fact that it looks as though someone has been in there before.CO was checked a little while back when it has it's mot. So i assume that it is still ok. Plugs are blackish in colour but, car does use a little oil. Base idle is set at approx 900rpm.


David H
Plugs are NGK9 gapped at 0.6ish.

Once again thanks for your help guys.If you think of anything else please let me know.As i'm sure you know how frustrating these little things can be...

Cheers

Graham.

 

Excuse the odd slip up with letters as the keys are right next to each other..

 

Graham,

Was the misfire there when u had the mot, as if plugs black after a good blast at operating temp, getting the wrong info to ecu, you change the cts, so if fuel pressure correct, and air filter good, then wiring, sensors map, throttle switch,
ats, co% and with the plugs black they will wisk up causing a misfire especially
champion race plugs 57/9's. u say new plugs was it there with old set as i have had new NGK , before for a bike took me ages to suss it as on the block sparking
but after 10, mins of running under compression no spark, so i give them a miss
although some people rate them, i prefer motorcaft,Agpr12pp8's up to 1.6,bar 0.8mm
gap. see what the co is first then go from there what u already suspect,

Dave,

 

Yes it was.Have changed cts.Fuel pressure was adjusted a while back because it was found to be low.Air filter is fine.I used to have C57's in and it was there with those plugs as well. I have cleaned out tps as it seems to have been apart before.
I will put the throttle body back on tonight and see if there is any difference.I don't expect there will be but, it's worth a try i suppose.

Cheers

Graham.

 

Have now noticed that it seems only to do this when the engine has started to get warmed up. Can't seem to make it do it when the engine is cold. So anymore help is very much appreciated and thank peeps for being patient.
Cheers

Graham.

 

GRAHAM,

co%, may just need fresh tune, set up. if u take the iscv plug off engine hot does it idle steady,

Dave,

 

Hello Dave,
I will try the iscv valve and see what happens. I don't think it alters but will make sure. Do you know how to check phase/tdc sync? Stu has suggested this to me.
Thanks for being patient Dave.

Cheers

Graham.

 

Graham.

I think what stu ment ,was you checked gap of TDCand PHASE SENSOR ,
but had u checked sensors, as the only info after you have set the TDC and phase sensor is from the ECU,it is a form of synchronize with tdc/phase sensor for ignition and the injectors, reason i asked about idle with iscv plug off engine
warmed up is if it was not steady, maybe vacuum leak, co% or compression problem, even ignition, had any joy with T/Switch? does the car stumble hesitate
on the throttle,

Dave,