Regarding question 11: with a MAF you could still get the same symptoms but for a slightly different reason. Cams with larger overlaps can cause reversion back through the intake at idle, and this pulsing reversal in airflow will make its way back to the MAF, as well, resulting in it getting "counted" more than once (bc the MAF can't tell/doesn't care which way the air is flowing, it's just looking at how much that hot wire gets cooled down). The end result is that the MAF overestimates the amount of air actually flowing in at idle and too much fuel is injected as a result. There can be some debate about how easy this is to tune around, but it's one of the reasons guys will get rid of the MAF all together and revert back to speed density bc it's generally easier to correct for this using the MAP and tuning for the lower vacuum.
The only problem with converting back to Speed Density is that if you're running an aggressive camshaft, a MAP sensor will read low vacuum at idle and cause a very rich idle - I've had to convert a Speed Density system to MAF for that very reason.
@@albertsautodiagnosticsllc2130 MACS is vehicle A/C specific, but Motor Age has great study guides for all ASE tests - Go here: passthease.motoragetraining.com/content/Motor-Age-Training.aspx?WP+-+Brand&hsa_acc=2604974794&hsa_cam=185710232&hsa_grp=108299918148&hsa_ad=429273534637&hsa_src=g&hsa_tgt=dsa-1225354435671&hsa_kw=&hsa_mt=b&hsa_net=adwords&hsa_ver=3
Ok so I’m working on a 2008 tundra 4WD with the 4.7L engine, customer complaint is intermittent start-stall, and vehicle also shuts off going around left turns. I am Able to confirm the vehicle is shutting down on hard left turns. all the monitors are set and there is no Codes or CEL. Fuel pressure seems fine, it just shuts off completely on left turns, but you can put it back in park and start it up again fine. Previous shop installed 8 new coils and repaired one of the Cam sensor wires. this is kind of a weird one, any thoughts?
@@177584 Shot in the dark, but water in the tank is a possibility... I've seen that on just one way turning. That'd do it without setting the CEL or codes, too. Although I have seen a Charger that had loose PCM pins doing that.
Hey, I already took a fuel sample while I was doing the fuel pressure testing, and the fuel seems fine, not contaminated and no water that I can see, appears fine: I’m suspecting faulty fuel pump control module cause I’ve seen them before.
@@177584 Possible, but you may not get water unless you totally empty the tank - I've had to do that - energize the pump and let it pump all the fuel out into a clean plastic container (bucket or drain pan) just to make sure there isn't water in there somewhere - it's easy to miss just getting a small fuel sample.
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Regarding question 11: with a MAF you could still get the same symptoms but for a slightly different reason. Cams with larger overlaps can cause reversion back through the intake at idle, and this pulsing reversal in airflow will make its way back to the MAF, as well, resulting in it getting "counted" more than once (bc the MAF can't tell/doesn't care which way the air is flowing, it's just looking at how much that hot wire gets cooled down). The end result is that the MAF overestimates the amount of air actually flowing in at idle and too much fuel is injected as a result. There can be some debate about how easy this is to tune around, but it's one of the reasons guys will get rid of the MAF all together and revert back to speed density bc it's generally easier to correct for this using the MAP and tuning for the lower vacuum.
The only problem with converting back to Speed Density is that if you're running an aggressive camshaft, a MAP sensor will read low vacuum at idle and cause a very rich idle - I've had to convert a Speed Density system to MAF for that very reason.
Good electrical questions really appreciate the videos
Thank you sir, i really appreciate the tests you put out👍
and plus iin that year it was a bap not a map plus the fuse pressure would jump up from 19 to maybe 26 psi on the fuelpressure sensor
Thank you sir for your time....✍️
on that 50 ford
I havey A6 and A8 I'm not sure what ones I'm going for next I was thinking of going for my HVAC A7 do you have any study material for the A7
I don't have any material for that but the mobile air conditioning society... MACS .. does
@@McCuistian do they have a website?
@@albertsautodiagnosticsllc2130 MACS is vehicle A/C specific, but Motor Age has great study guides for all ASE tests - Go here: passthease.motoragetraining.com/content/Motor-Age-Training.aspx?WP+-+Brand&hsa_acc=2604974794&hsa_cam=185710232&hsa_grp=108299918148&hsa_ad=429273534637&hsa_src=g&hsa_tgt=dsa-1225354435671&hsa_kw=&hsa_mt=b&hsa_net=adwords&hsa_ver=3
@@McCuistian thank you
Hey Richard, I have a question regarding trying to diagnose an issue with a Toyota Tundra, do you have an email I can contact you with?, thanks
Let's do it here
Ok so I’m working on a 2008 tundra 4WD with the 4.7L engine, customer complaint is intermittent start-stall, and vehicle also shuts off going around left turns. I am
Able to confirm the vehicle is shutting down on hard left turns. all the monitors are set and there is no Codes or CEL. Fuel pressure seems fine, it just shuts off completely on left turns, but you can put it back in park and start it up again fine. Previous shop installed 8 new coils and repaired one of the Cam sensor wires. this is kind of a weird one, any thoughts?
@@177584 Shot in the dark, but water in the tank is a possibility... I've seen that on just one way turning. That'd do it without setting the CEL or codes, too. Although I have seen a Charger that had loose PCM pins doing that.
Hey, I already took a fuel sample while I was doing the fuel pressure testing, and the fuel seems fine, not contaminated and no water that I can see, appears fine: I’m suspecting faulty fuel pump control module cause I’ve seen them before.
@@177584 Possible, but you may not get water unless you totally empty the tank - I've had to do that - energize the pump and let it pump all the fuel out into a clean plastic container (bucket or drain pan) just to make sure there isn't water in there somewhere - it's easy to miss just getting a small fuel sample.