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1999 4E-FE Misfire - Code 42


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Hi guys,



After having much fun hooning time I am getting sick of an intermittent misfire (which is now getting worse and more regular) which is most noticeable pulling from low RPM in a high gear. It really sputters and craps out and backfires every now and then.



I have a CEL and after checking the code I have only got Code 42 - Vehicle Speed Sensor.



What sensor is this referring to exactly and could it have some effect on the engine management? It seemed to be fine all day today but after going out tonight it is as if the car is stopping the hooliganism. Sad times. :(



If I accelerate smoothly I don't seem to have a misfire. If I plant the throttle it can hesitate sometimes. When revving in neutral from idle it can be very grumbly.



Any ideas here? It will get me home for sure but I want to minimise damage to the engine if this is harming it in any way.



KP


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There's no dizzy cap its a twin coil wasted spark ignition system :) But thank you - we did test the leads just today!



We tested the HT leads and coils for resistance and they are absolutely spot on. The Spark Plugs could do with replacing but wouldn't cause this issue.



What we did find using a Gunson Colour Tester is that the engine is running lean under full throttle = fuel supply issue. When we applied a positive pressure to the pressure regulator it appeared to ease the misfire, thus I will be fitting an adjustable fuel pressure regulator to bring the pressure up to snuff. That should have it sorted. :D



Does anyone know of a decent kit for not much money that bolts straight on? I want to raise it to 2.8Bar if possible.



KP


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Forgot you were using the Gen3 DIS ignition system.

As for the FPR, dont get the cheapest one you can find (ebay) because they are dog shit, stick at 4bar and cause hassle.

Something like an aeromotive, sard, etc and you'll be sorted.

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Ah ok thanks for the advice, I was looking at this one but may rethink that:



http://www.ebay.co.uk/itm/UNIVERSAL-FUEL-PRESSURE-REGULATOR-TOYOTA-MR2-CELICA-SUPRA-STARLET-W-GAUGE-RED-/271300630796?pt=LH_DefaultDomain_3&hash=item3f2ac7190c



The misfire is getting bad - anyone got a spare lambda sensor? I only have the one heated sensor and its Bosch not the genuine Denso so I think its giving duff readings. ECU hasn't whinged about it but it may be part of the issue.



KP


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This one looks about right - according to the Denso catalogue the direct fit to the original downpipe is the DOX-0225 (1997-1999) and the universal sensor is DOX-0111 which is £35 not £80! I need the universal one anyway, can someone take a look at this and confirm I'm not talking bollox?



http://www.autodesignplus.because/editor/image/stranky3_soubory/d-denso-lambda-sensor-catalogue-2008-2009.pdf



KP


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Having reconnected the O2 sensor and checked its voltage, I can confirm that it is working between 0.1v and 0.9v which is as specified by Denso and Bosch - so I believe I am safe in assuming they both send the same signal and it shouldn't make a difference to the ECU which one I use.



Annoyingly it didn't solve anything however I may try resetting the ECU tomorrow with it connected and see if it responds better.



KP


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Sure enough, I couldn't see the wood through the trees. After installing a new set of Spark Plugs and chucking some fuel system cleaner in the tank the misfire has disappeared. Runs spot on now!



KP


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