LS430 Transmission Hesitation

[LEDMaestro101]

Ok guys, just an update and a close to this thread (thankfully) though I must walk with my tail between my legs admittedly. So the car was getting worse, had it booked in to go to my local garage at the end of this week so I thought I would try one last thing, the MAF sensor. Now at the time of ordering the part from eBay (aftermarket brand, not Denso) I forgot that I had already cleaned and then replaced the MAF a couple of months ago with a new Denso unit and dismissed that as being a cause of my issues as nothing changed upon replacement.

BUT...the new MAF arrived Saturday, had to drive out to the collection office on sunday to pick it up, car drove like a pig as per usual but I eventually arrived and fitted it in the car park. WHAT A DIFFERENCE!!! All my issues are gone and I mean ALL of them, no lag, no hesitation, no lurching....it's like a brand new car and all for an £18 MAF on eBay! So it makes me wonder if I had picked up a dodgy Denso MAF a couple of months ago! Having come from owning a load of IS200's and a CT, I always felt like they had a lot more power than my LS....not any more! The LS absolutely flies!! 

Suffice to say, if your car is suffering from lag or lack of throttle response, check the MAF first and replace with a cheap unit before forking out for Denso! if nothing else, it's a good diagnostic tool. Seems like I was so caught up with my gearbox and assuming that was the issue, I didn't think to stop and go back to the basics!

Thank you to all contributors to this thread, you've prompted me to do some preventative maintenance while trying to sort my issue so there is a plus side haha.

[GrahamG]

Very pleased for you J. and thanks for adding to our knowledge base with your report.

Might it have been a poor connection rather than a dodgy Denso MAF? In any event you do not need to care any more.

 

[LEDMaestro101]

Thanks Graham, it is such a wonderful relief haha. As for the sensor, I'm not too sure. I originally checked continuity in the connector and checked resistance of the original and new denso MAF when I first replaced it and they seemed the same (or close enough). Same results through reading the sensor values on OBD2 as well but seeing as the new aftermarket sensor worked as soon as I plugged it in, I doubt it was a wiring/connector issue. Haven't checked my aftermarket sensor values against the ones I was getting on the other 2 units though, might do that during the week, more for piece of mind than anything else!

[runsgrateasanut]

Do update on the results of your check, please.

Would you not have needed to disconnect the Battery to update your ECU on the new MAF?  

Struggling with a misfire issue under load, so reading anything and everything that might explain.

 

[The-Acre]

Nice to read about a positive outcome! Well done.  And as Graham says, it adds to our knowledge.👍

[LEDMaestro101]

Thanks guys but it was down, in part, to the existing information on this forum that lead to the fix. It would have been fixed without me posting if the other MAF sensor had worked!

I will take the old MAF with me to work and get some readings between the old and new unit during my lunch break for you to compare. Hopefully it helps with a possible solution or, at the very least, narrowing down potential problems. 

[runsgrateasanut]

On 8/20/2019 at 8:57 PM, LEDMaestro101 said:

Thanks guys but it was down, in part, to the existing information on this forum that lead to the fix. It would have been fixed without me posting if the other MAF sensor had worked!

I will take the old MAF with me to work and get some readings between the old and new unit during my lunch break for you to compare. Hopefully it helps with a possible solution or, at the very least, narrowing down potential problems. 

Aa couple of Q's?.  Did you check the MAF at work?.  Second, assuming the MAF sensor is similar to the one on the LS400 (?) did you find that you had to apply pressure to make it seat?.  I bought a cheapy to test and firstly it had a strange plastic ball sticking out of the "post" part (not the sensor central part) which to remove I discovered it was two strands of wire. (Assume it was to stop someone returning it as faulty claiming not to have installed it ??). Anyway, they removed, and the unit is slightly proud of the base plate one end if tilted.

It may screw down as its the central core does have an "o" ring as does the original. Just curious as to your experience of installation of the Chinese replacement. No gasket to this part and if not seated properly will it give a false reading, or suck in dirt,  is my thinking.

[LEDMaestro101]

Hi, sorry for the late reply. I didn’t end up taking readings in the end, my apologies. My replacement was a perfect fit, no need to apply pressure in any way. Just slotted right in and screwed down. 
 

there wasn’t any other type of plastic on mine, looked identical to the original Denso part so I can’t comment on yours unfortunately. Honestly can’t remember if the 430 has an o-ring on the MAF but I assume it does (to prevent false readings as you hinted to). 
 

the whole idea is to give the ECU an accurate reading of air coming into the engine. If there was a gap between the sensor and the box where it is seated then it would Possibly (as you said) draw in air from the engine bay which could skew the actual air intake values. That is worst case scenario though. 
 

I would usually go OEM for sensors but at the time I wasn’t sure if the MAF was my issue, it just happened to be a lucky guess. To my surprise, the aftermarket MAF is still going strong and my car feels incredible. 
 

if you have any other questions then please feel free to ask and I’ll help as best I can.