[Air intake temperature SOAR when I step off the gas.]

So I checked some things out and the only sensor that makes sense for the AIT sensor is this one:

 

 

It's basically the only sensor anywhere on the intake, from filter to heads, si I'm guessing i'm right.

 

the sensor is screwed in straight into the manifold, so heat probably does transfer and could explain part of the spike, but again, if that was the main cause, I'd have the exact same issue when I de-clutch... 

 

anyone else (with a turbo) get spikes in heat when they let the gas pedal go?  if so, how high?

 

 

[Air intake temperature SOAR when I step off the gas.]

SleeperZ, if i understand correctly, you're saying that the limited air flow at closed throttle might not be enough to make up for the hot metal's radiant heat might surroung the probe..?

I like the idea, but wouldn't the same thing continue to happen when i de-clutch?

Really, the only variable that changes between the two situations is the engine rpm (as driven by the wheels) is high when in gear, and at iddle when on neutral.

This just points out i have to find the sensor location...

Still wondering if this is normal or worrisome...

[Air intake temperature SOAR when I step off the gas.]

Hi. Ill check the plumbing for the ait sensor. I'd not realised about it being the only one there. Thanks!

 

As for the intercooler, that's an interesting theory. I'd have thought the longer it stays there the more it can be cooled (unless the i/c is soaked), but i'm no engineer myself, so i really dont know...

Can anyone enlighten us?

[Air intake temperature SOAR when I step off the gas.]

I changed all the values to franheight and mph. 

 

thanks for the suggestion.

 

I'd love to followthe wires, but I have two issues: I don't know which one to start following (I guess I could take the plug to the megasquirt apart, but I did that once and i's not well made so I spent 7 days playing with it after to get the car working) AND all the stupid wires are the same Gdamn color...  

 

If it turns out ot be an issue, I definately will.

[Air intake temperature SOAR when I step off the gas.]

Thanks for the answer.

 

I don't know where the sensor is and how it's mounted ( I don't even know what to look for).  

 

 

Besides the turbo housing and the intake manifold (which is probably farther down the road from the sensor), is there anything else that is above 100 degrees that could heat up the air?  The pipes sure aren't THAT hot, I can touch them when the AIT is above 70 after a few minutes of idle.  

 

still is 100 degrees AIT acceptable or a cause for worries?

[Steering Wheel Wobble at Highway Speeds]

I don't have a cause to suggest, but clearly, you need to drive it about 120 all the time.  Simple as that. 

 

 

I had a bad vibration when I bought my 280zx, but it was caused but a flat spot on the tires due to the previous owner having had to do an I suspect shit-your-pants-type emergency stop.  Got new tires and that disappeared immediately. But that does not seem to be the problem. I also had a bad vibration that could be felt in the back of the seat that was due to the get-pale-when-you-realise drive shaft getting loose and being this close to falling off. but that does not seem to be the same problem at all.

[Air intake temperature SOAR when I step off the gas.]

Hi guys.

I have a 1983 280zx, modified by the guy who sold it to me.  Rebuilt engine, T3/T4 turbo, front mount intercooler, blow-off valve, megasquirt…  The air filter was located behind the driver side headlight, which is good for protecting it from dust and rocks (and it gets fresh air through holes in the radiator mount for intercooler piping) but it breathes gross hot air when stopped or doing city driving (upwards from 120 degrees Farenheght)).  See photo for details. 

 

 

It was supposed to need nothing but megasquirt tuning, but the more I play with it, the more I think there are other issues (I think not all the injectors work well amongst other things).  I’m also new to the turbo thing, only having had stock NA engines before. 

 

The issue that brings me here today is that I am embarking on a cold air intake build (I plan on building a scoop that goes under the rad and maybe back up in front of it (no more room to go through the rad supports as the weird intercooler has both in and out on the same side, that side), with the filter in an isolated box between the rad and the engine.  See upcoming post with air pressure and temperature tests...) and also am looking into isolating my intake piping (see other posts on that, with data too).  I don’t want to build things that are useless, so I started taking data before so I can compare before and after.  I’ve been measuring and comparing temperatures under various situations and came to the realisation that I might have a problem (not sure, thus the post).

 

If I cruise on the highway at steady speed (say 75mph), I get steady temperature: today at ambient 82 degrees, I got 90 degrees at the air filter, and 120-130 degrees at the air intake temperature (AIT) sensor (I don’t actually know where the guy put that sensor.   Any clues?).   I’m not certain how good this is, but it does not seems too too bad (still not happy that I’m gaining 65-85 degrees WITH an intercooler under very little load and high air flow.  Opinions?).

The potential problem occurs as soon as I lift of the gas.  If I lift off a little, say to slow down to 60mph(without de-clutching), the temperature climb real quick to 155-175 degrees AIT, while everything else stays the same (air filter temp, RPMs, air flow…).  If I completely let go of the gas (without declutching), the AIT skyrockets to 190-215 degrees.  In both cases, the temps stay high for a while and only then decrease slowly (unless I give it gas, at which point they go back down quick enough I guess).

 

If I let go of the gas but immediately de-clutch and stay in neutral, the temperature goes up to 150-165, but then comes back down on its own quick enough.

 

I thinking the really high temperature I see when I don’t de-clutch might be a combination of A) slower moving air that gets to take the time to absorb more heat and B ) the fact that, because the engine is working still, there is a significant amount of exhaust that might make the turbo work and thus heat up the air.   But how come the intercooler wouldn’t be making up for that?

 

So, is that temp spike normal(ish)?  Should I be worried?  Any explanations?

[Prothane Polyurethane Bushing Install on 1980 280ZX (lots of photos!)]

Thanks for the replies guys. Essentially, the car currently feels like jello: soft/slow steering, a lot of roll in the corners, feels loose when i hit bumps...

My problem is i have no money for this (wife who hates the car, kids, mortage, etc) so i can only affort small cheap things.. And i dont really plan on changing anything else ( no low profile tires no custom suspension bits, nothing other than upgrading stock parts as they break, like shocks eventually, bushings, etc....)

Thus i though bushings might be a good start since they are cheap and supposedly make a significant difference. But i wouldnt want to feel like im riding a tank.

In the end though i got all the bushings that the kit contains quoted at the local napa, and it comes to double the cost of the poly kit. I guess that takes care of that and i could eventually change it back later if its too much....

[Prothane Polyurethane Bushing Install on 1980 280ZX (lots of photos!)]

ok.

 

I'm resuscitating this tread, as it's one of the most complete I could find about this issue

 

I've got a 83 280zx daily driver ish that feels soft. the shocks are probably very old, the bushing probably factory.  

 

I was psyched about the prothane poly bushing kit, but a lot of people say it makes the car harsh to drive around (apart  for the tc arm issue). 

 

Are there other options, other kits that offer softer bushing?  I'm thinking that buying individual OEM bushing at the dealer or even at the local auto part store is going to amount to much more than the 125$ for the prothane kit..  

 

Otherwise, what are people's impression on comfort after instaling the poly kit?  it should be much different that the old stock ones, but what is the difference?  vibration?  noise?  harshness when going over bumps and holes?  and how much?

 

thanks!

 

seb