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Hello is this thing on????
I find it funny, people post they need help with a car yet leave out important info i.e. Year Make Model and then some. And replies like crazy to those posts.
I have legit question (video camera not pick up how connected ) and I get no response.
update …. The scope has ability to do amps (10 amps max) using the pos+ and neg- leads
so i was wondering if you did ch2 that way or do you have 2 amp clamps
maybe i should watch video again….ive watched it twice but on a stupid small screen(phone)
Thanks
Also my explanations above translate back and forth to various cars and styles of sensors.
Example : My favorite line is, ” I could walk into most auto shops and ask techs to explain to me how to test a TPS sensor…..most could do it. But if I hand them a MAP sensor they are scared to be creative and put a vacuume hand pump on it and do the same TPS test”.
In other words a 3 wire sensor is a 3 wire sensor.
FYI if it is a 2 wire then its a reluctor and will generate its own voltage typically ac sine wave.
if its a 3 wire then its a hall effect. This would be a digital square wave (on off signal) that hertz reading would change based on speed.
The wires would consist of referance voltage (most likely 5v)
A ground, and a signal wire. The signal wire is the one to test the hertz on.i suspect this coil on plug design might have the transistor built into the coil pack
id be curious if the wireing is truley ok all the time. Id suspect it could pull down and zap the transistor at times. Id make sure motor mounts ok and wiggle test harness. Inspect high probable areas harness could be chaffed or being pulled.Also where are you getting the parts ?
an old saying is New does not mean Good.
However at some point you have to trust the part….agreed.
P0300 just fyi not trying to fix your car
If memory serves this is random misfire. Or dreaded random misfire code.
depending on car or brand a lot of things can do this.
1.Timing issues i.e. knock sensors
2. Often missfire on #1 cyl thus confusing pcm on fireing order so to speak
3. intermitant and or bank vacuume leak that often goes away hot.just some tidbits
1. does your scan tool show closed loop capabilities
2. what does coolant sensor and iat read
3. is this a single wire o2 sensor
4. does map sensor voltage read roughly 2.2v or little less at idle
5. after finding super rich condition and replaced injectors did you change oil
6. did you pinch off canister purge , might have saturated canister….need to prove.
7. ( do at idle only) disconnect MAF sensor plug, how does it idle, remember un metered air leaks on vehicals with Maf will typically result in rough idle8. if single wire o2 , un plug it and harness side jump it on off with test light hooked to ground, that is, using then test light tip to harness side on and off the pin quickly while monitoring scan tool.
In old days we liked to bench test 02 in a vice, using propane torch and dvom on volts or preferably with DSO…..the premise is the propane torch uses up oxygen so it reports rich
then quickly remove torch and it should very fast show lean.p.s. reason for my questions such as coolant sensor, if single wire o2 when gets hot it starts to work this might fool you into thinking its in closed loop. On gm of that era if coolant sensor not warm it may never see closed loop. A disconnected or open in coolant sensor circuit on gm cars often reads -40 on scan tool. This is quick test of computer and wireing, diconnect it and look for -40 on scan tool. As an engine gets warm it needs less fuel at idle. If you are not really in closed loop the ecm may be giving more pulsewidth to injectors by thinking engine still cold. Thus your rough idle when warm and excessive fuel in warm engine. Bad Coolant sensor reading can fool ecm , might tell ecm the car is in alaska winter. The ecm back then are not as smart as todays cars.
