Hi Scannerdanner. I learn a lot from your videos as I'm new to a labscope but could I make a video request on wideband o2 sensors because I find it hard to diagnose these and think other viewers would benefit from it too? Also is this topic covered in your book and what's you web address where I can get a copy? Thanks for your hard work.
@assassinscov No plans as of right now. I'm still not confident enough with them to shoot that at this time. The heater circuit tests are identical but as far a pinpoint testing the signal wire(s) with a scope, it cannot be done with ease. The PCM monitors micro amp changes (not voltage) in the signal circuit to determine ratios. My test equipment will not read that low of amperage. So all testing is done with scan data only. I'll work on it. For book info. see my homepage for site
You know what else Scannerdanner ther was no pcv valve in place for bank2 on valve cover. Back 1 has a pcv valve I don't know if this system calls for one or not
@fivefortyeye540i ok, so no rubber boot in between then? The throttle body bolts directly to the manifold? Sorry for misleading you if that is the case.
Yes I blocked of throttle body with latex glove I put it over Maf sensor housing good positive pressure it inflated.. When I original took off intake manifold to replace pop off valve and put in new gasket... I only detached half the throttle body left other half
I took it off and thoroughly inspected it, I put it back on smoked the the throttle down stream of Maf sensor smoke did come from top side of filter box wher it connects to cover air filter Now that u mentioned that agin I'm going to try to seal it of and see if that brings the numbers down..
@fivefortyeye540i are you sure we are talking about the same thing? If you took it off that means you had the entire throttle body off. Its not that easy to remove. Most systems the throttle body is directly mounted to the intake with a gasket in between. On this one there is a small rubber boot connecting the two together. Look close.
@fivefortyeye540i also when you smoke test this engine you need to completely block off the throttle body. This will put the intake under a slight pressure which will reveal any leaks easier.
I think I have figured it out on the 4.6 I put new wires and plugs in. Since then i have been running the caddy on I off tring to figure out this lean condition.. So I went back pulled the plugs on bank 2 2plugs wher white (lean) and other 2 wher dark... Fuel delivery... Pulling injectors tonite....
@fivefortyeye540i I thought you said fuel trim was high on both banks? If it was just the one bank there is also a timing chain problem to consider. I believe this engine has a primary and two secondary timing chains. So maybe the one bank the chain is off a tooth or two?
@fivefortyeye540i Not sure, my diagnosis ended here. Too many miles to tear into this one, it wouldn't be worth it. Unplugged the K.S. and she is driving it until it dies.
Loop status with the engine cold may also be why the problem doesn't present itself while cold.
JohnxWaynexGacy 3 weeks ago
@JohnxWaynexGacy Good point thanks!
ScannerDanner 3 weeks ago
Hi Scannerdanner. I learn a lot from your videos as I'm new to a labscope but could I make a video request on wideband o2 sensors because I find it hard to diagnose these and think other viewers would benefit from it too? Also is this topic covered in your book and what's you web address where I can get a copy? Thanks for your hard work.
assassinscov 1 month ago
@assassinscov No plans as of right now. I'm still not confident enough with them to shoot that at this time. The heater circuit tests are identical but as far a pinpoint testing the signal wire(s) with a scope, it cannot be done with ease. The PCM monitors micro amp changes (not voltage) in the signal circuit to determine ratios. My test equipment will not read that low of amperage. So all testing is done with scan data only. I'll work on it. For book info. see my homepage for site
ScannerDanner 1 month ago
@ScannerDanner information, also all of my videos are embedded with my website address where my book is sold. Check it out. Thanks for you interest.
ScannerDanner 1 month ago
You know what else Scannerdanner ther was no pcv valve in place for bank2 on valve cover. Back 1 has a pcv valve I don't know if this system calls for one or not
fivefortyeye540i 1 month ago
Ther was only a gasket thir for throttle body which I replaced.. This is a 98 Cadillac eldorado base model 4.6 litter.
fivefortyeye540i 1 month ago
@fivefortyeye540i ok, so no rubber boot in between then? The throttle body bolts directly to the manifold? Sorry for misleading you if that is the case.
ScannerDanner 1 month ago
Yes I blocked of throttle body with latex glove I put it over Maf sensor housing good positive pressure it inflated.. When I original took off intake manifold to replace pop off valve and put in new gasket... I only detached half the throttle body left other half
with intake
fivefortyeye540i 1 month ago
I took it off and thoroughly inspected it, I put it back on smoked the the throttle down stream of Maf sensor smoke did come from top side of filter box wher it connects to cover air filter Now that u mentioned that agin I'm going to try to seal it of and see if that brings the numbers down..
fivefortyeye540i 1 month ago
@fivefortyeye540i are you sure we are talking about the same thing? If you took it off that means you had the entire throttle body off. Its not that easy to remove. Most systems the throttle body is directly mounted to the intake with a gasket in between. On this one there is a small rubber boot connecting the two together. Look close.
ScannerDanner 1 month ago
@fivefortyeye540i also when you smoke test this engine you need to completely block off the throttle body. This will put the intake under a slight pressure which will reveal any leaks easier.
ScannerDanner 1 month ago
What should compression be on this engine? If timing has advanced a compression test would show higher then normal compression correct?
fivefortyeye540i 1 month ago
Yea Ltft are high on both banks I pulled bank 2 plugs because that bank was the hightest Ltft stft are normal after warm up on both banks
fivefortyeye540i 1 month ago
I think I have figured it out on the 4.6 I put new wires and plugs in. Since then i have been running the caddy on I off tring to figure out this lean condition.. So I went back pulled the plugs on bank 2 2plugs wher white (lean) and other 2 wher dark... Fuel delivery... Pulling injectors tonite....
fivefortyeye540i 1 month ago
@fivefortyeye540i I thought you said fuel trim was high on both banks? If it was just the one bank there is also a timing chain problem to consider. I believe this engine has a primary and two secondary timing chains. So maybe the one bank the chain is off a tooth or two?
ScannerDanner 1 month ago
Thanks for another good video. Very educational!
dreamer2355 1 month ago
That sounds like an engine that has had regular oil changes at 15k miles or so...
beefystik 1 month ago
Lifters or piston slap??
fivefortyeye540i 1 month ago
@fivefortyeye540i Not sure, my diagnosis ended here. Too many miles to tear into this one, it wouldn't be worth it. Unplugged the K.S. and she is driving it until it dies.
ScannerDanner 1 month ago