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[quote=”Haloruler64″ post=65168][quote=”ToyotaKarl” post=65061]Eric, I am in complete agreement about finding the known problems, and you did find a vacuum leak indeed.
So did you seal up the leak (what someone was probably trying to do before when they glued it together) and flush, fill and bleed the cooling system?
I don’t know if you noticed but when you shot the video there were definite differences in the readings of the O2 sensors. O2S21 did not look like it was moving in a full range (as compared to O2S11). Now, I know that both upstream will never match but they should be fluctuating between .1 and .9. O2S21 did not appear to go below .295, where O2S11 went to .135. This would cause me to check the O2 sensors. Perhaps a different type (brand) of sensor was being used, or Bank 2 O2 sensor is getting lazy…. I know that not using DENSO O2 sensors on Toyotas can cause issues as well as mixing brands of O2 sensors.
I know I only saw a couple of seconds of the O2S21, so maybe it did move full range… Suppose we could get into the chicken and egg discussion that the O2 is richer because the Bank 2 LTFT was increased! :woohoo:
As always, thanks for all you do.. and disagreement isn’t disrespect!!
Karl![/quote]
O2 sensors don’t operate at full range when idling. To get an O2 sensor to switch properly, you’d need to rev the engine up to 2k RPM. That’s how I tested my O2 sensors. And even with a lazy O2 sensor, that wouldn’t cause start troubles. The O2 sensors don’t come into play until the ECU goes into closed loop, which is when the engine is warm.[/quote]
I am not talking about cold start difficulty… My point is about why one bank LTFT is at +5 and the other is at 0… The possible explanation… The video shows both O2 sensors readings and one is much more dynamic than the other….
🙂
Karl
[quote=”theoldwizard1″ post=65132][quote=”EricTheCarGuy” post=65028] If there was a heater failure there would have been a code for it. Besides, the O2 is not active at cold start up anyway. As for the coolant, I advised the customer that they would need to flush out the old coolant …[/quote]
Did the customer at least agree to the cooling system flush ? Seems odd that that maintenance item was skipped, especially when the rest of the engine compartment seemed reasonably clean !
Side question. New or repeat customer ? Do you think they will be back ?[/quote]
First, this video was shot last fall. They were a friend of a friend and I doubt they’re coming back. Even if they did come back it would be some time before I would get to them and be able to post a video. The reason I hadn’t posted this video was because I was not able to fix the problem. Thing is, I had a hole in the video schedule I had to fill before the Sonoma engine series started and this fit the bill. There really is nothing more to it than that.
[quote=”EricTheCarGuy” post=65028]… Besides, the O2 is not active at cold start up anyway… [/quote]
[quote=”Haloruler64″ post=65168]…O2 sensors don’t operate at full range when idling. To get an O2 sensor to switch properly, you’d need to rev the engine up to 2k RPM.[/quote]
You guys are very “old school” with that kind of thinking !
An O2 sensor with a heater giving valid data very quickly (< 1-2 minutes) after startup, even at idle. This is the whole point of having a heater ! Even ScannerDanner commented in on of his videos how quickly this happened. The software will detect if the sensor is not properly responding and try to force it lean and then rich a couple of time before turning on the Check Engine light. If the O2 is not heated (older vehicles), then yes, a minute or so of high idle is required to get it to function. I don't understand the term "full range". EGO (O2) sensors "switches", changes from high to low or low to high voltage, when the exhaust gases pass stoichiometry. Some newer vehicles are now using heated "wide range"/analog/Universal EGO sensors that give a linear response (voltage proportional) over a range of air fuel ratios.
[quote=”ToyotaKarl” post=65358][quote=”Haloruler64″ post=65168][quote=”ToyotaKarl” post=65061]Eric, I am in complete agreement about finding the known problems, and you did find a vacuum leak indeed.
So did you seal up the leak (what someone was probably trying to do before when they glued it together) and flush, fill and bleed the cooling system?
I don’t know if you noticed but when you shot the video there were definite differences in the readings of the O2 sensors. O2S21 did not look like it was moving in a full range (as compared to O2S11). Now, I know that both upstream will never match but they should be fluctuating between .1 and .9. O2S21 did not appear to go below .295, where O2S11 went to .135. This would cause me to check the O2 sensors. Perhaps a different type (brand) of sensor was being used, or Bank 2 O2 sensor is getting lazy…. I know that not using DENSO O2 sensors on Toyotas can cause issues as well as mixing brands of O2 sensors.
I know I only saw a couple of seconds of the O2S21, so maybe it did move full range… Suppose we could get into the chicken and egg discussion that the O2 is richer because the Bank 2 LTFT was increased! :woohoo:
As always, thanks for all you do.. and disagreement isn’t disrespect!!
Karl![/quote]
O2 sensors don’t operate at full range when idling. To get an O2 sensor to switch properly, you’d need to rev the engine up to 2k RPM. That’s how I tested my O2 sensors. And even with a lazy O2 sensor, that wouldn’t cause start troubles. The O2 sensors don’t come into play until the ECU goes into closed loop, which is when the engine is warm.[/quote]
I am not talking about cold start difficulty… My point is about why one bank LTFT is at +5 and the other is at 0… The possible explanation… The video shows both O2 sensors readings and one is much more dynamic than the other….
🙂
Karl[/quote]
Oh, my apologies. I absolutely see what you mean. Yeah it could definitely be a partial issue with the O2 sensors, but a very minor one. Fuel trim of +5% is very small.
[quote=”theoldwizard1″ post=65762][quote=”EricTheCarGuy” post=65028]… Besides, the O2 is not active at cold start up anyway… [/quote]
[quote=”Haloruler64″ post=65168]…O2 sensors don’t operate at full range when idling. To get an O2 sensor to switch properly, you’d need to rev the engine up to 2k RPM.[/quote]
You guys are very “old school” with that kind of thinking !
An O2 sensor with a heater giving valid data very quickly (< 1-2 minutes) after startup, even at idle. This is the whole point of having a heater ! Even ScannerDanner commented in on of his videos how quickly this happened. The software will detect if the sensor is not properly responding and try to force it lean and then rich a couple of time before turning on the Check Engine light. If the O2 is not heated (older vehicles), then yes, a minute or so of high idle is required to get it to function. I don't understand the term "full range". EGO (O2) sensors "switches", changes from high to low or low to high voltage, when the exhaust gases pass stoichiometry. Some newer vehicles are now using heated "wide range"/analog/Universal EGO sensors that give a linear response (voltage proportional) over a range of air fuel ratios.[/quote] This is true, many O2 sensors have heaters. However, even heated, they still do not contribute to starting the car. That's the point I was trying to make. A CEL generally comes on when the fuel trim exceeds +/- 25% as far as I remember. Then it becomes a serious issue. My car had one that was +20% constantly, and it ended up being a vacuum leak. My O2 sensor was brand new, of course, so that didn't contribute. But you are very correct in what you're saying And about revving the car, that's not to warm it up. The O2 sensor is more active when the engine is under load. It's easier to see if it's "lazy" when at 2k RPM. This had nothing to do with heat. And about those wide band modern O2 sensors, I'd love one for myself 😀
IM posting this for future reference……
Let me start off with this disclaimer: From what I understand when GM made the spider (fuel injectors) they started with the CPI aka the fuel spider with one injector in the center. Then they released it’s bastard child, Which was the poppet stye injectors, they are known to gum up due to the placement and How the injectors work this was 1996-2002 or 2003 I think not to sure on the dates. In 2003 and up the replaced it yet again with the MPFI which was similar to the poppet style but had indivual electronic control of every injector. The aftermarket even delco has made the revisions for the older poppet style injectors since they are known to fail. Since the connector is broken which is not hard to do imo brittle plastic. It may be the case that someone replaced it due to a random misfire or through some other diagnosis there is a seal that goes around the top of the fuel spider picture will follow another problem with these vehicles are the fuel pressure regulator opperate in the range of 50-60 psi with key on. Which could add another chalk mark on the cold start. The after market MPFI systems are alot better then the oem in fact delco offers a conversion to MPFI on these vehicles.(1996-2002 spider systems)
From what Im Speculating and this is again for reference to expand a knowledge base on these popular Vortec engine’s, by the looks of the coolant blackish and the low oil im again speculating the lower intake manifold gaskets are gone from the Delco antifreeze which is all to common around 150000 miles from what ive seen or heard. This is just yet another possible problem of this little vortec which can be a very stout motor if kept up. I recommend if you replace the fuel spider go ahead and replace the lower intake manifold seals as well.
NOTE: I CANT POST PICTURES,BUT THERE IS A SEAL AT THE VERY TOP OF THIS INJECTOR ON THE INATKE MANIFOLD SIDE BELOW THAT ELECTRICAL PLUG.
Thanks very much for your input. As for this truck, the people that owned it were looking for a ‘quick fix’ and decided not to do anything with the vehicle as the expense of the injector set was more than they wanted to spend. Unfortunately, that means we’ll just have to guess as to what the real issue was with this truck. I’m certain that there was a massive vacuum leak however, but once again, we’ll never know.
Thanks again for your input.
P.S. As for posting pictures, we have a thread on that in the “Suggestion Box” thread. The biggest problem people seem to have is making sure the files they are uploading do not exceed our file size limit. Here’s a link.
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