Hey guys, pretty broad general open ended question here

I am having a heatsoak problem with my car/ecu where I can cruise around and IATs will vary between 90*-100* depending on temperature. And if I park the car, go in a store for 15 minutes and come out, my ECU will be showing IATS in the 130*-140* mark and the car significantly leans out, and is fairly difficult/embarassing to drive as it wants to buck for atleast 1-2 minutes of driving before the car corrects to proper IAT's thats its actually sucking in and goes back to proper afr's

I am curious to know if I would see a measurable difference by spacing the rear of the hood to give a space for the hot air to escape/vent while driving and more importantly after stopping to help prevent or atleast reduce the heatsoak of the engine from the hot turbo/manifold

I am OBD0 and running turboedit and the IAT enrichment adjustments are just to crude to make a difference, they only allow adjustment at 110/160/290 degrees... makes fine tuning damn hard

I have wrapped my downpipe and wastegate dump, and purchased a turbo blanket but of course it did not fit so Im in the process of exchanging it. I know a good solution would be to relocate my IAT sensor to the chargepipe, but I am not quite wanting to do that yet, as I was silly and got my pipes powdercoated already and would hate to muck that job up.

So other than looking like a JDM superhero with a lifted hood... will it work

 

Honestly I think the problem is the fuel injectors heat soaking not IATs. You could easily test this theory by zeroing out the IAT trim. Or try blasting the injectors with compressed air before starting. It doesnt take 1-2 mins to ingest the air from the intake but I found when you hold the throttle to rev to 2-3k for 10-15 seconds the problem goes away. I think fuel passing through the injector keeps it cool.

Heres something I found on the subject when I had this issue. http://m54megasquirt3.blogspot.com/2...heat-soak.html

Its worth noting the newer Bosch EV14 style injectors do not seem to be as affected by heat soak.

 

Never even heard of injectors heatsoaking! They are prescision 680's

The problem does not go away with holding the revs high for 10-15sec, it only goes away when the IATS drop back down to 110* or below, which with the oem sensor seems to take some time.

Wish it was instant reading

 

Sounds like a tuning issue. My car used to do this and i had to fine tune the intake temp corrections. that helped some but then i found that my idel set screw backed it-self out. What this did is make the thottle plate stick when hot and would cause it to idle horribly. i put a screw back in, unhooked ide motor and set base idle with screw. after that problem went away completely

 

I have the same problem, after I got the car tuned. On very cold days my car would runs super rich (10.00) if not lower, so I told him about it and he sent me a leaner cold start. But now it's hot out so after car worms up and I restart it it's very lean almost dies for about 1-3 mins. Thou I'm on s300 with id1000. I'm going to mess with my cold start hot start soon.

 

Well if I had a program with more detailed IAT columns I could probably adjust and account for it. But I dont. The car runs AMAZING except when trying to hot start, and I have the laptop connected while doing these tests and it only leans out when the IATS are 120+ when its actually sucking in 100 degree or less air

I was hoping there was a nice way to reduce heatsoak of the sensor, other than the thermal gaskets I have already installed.

Possibly a sensor that is accurate to the second, this sensor seems to take forever to correct back down to proper IATs

 

Despite the lack of resolution for IAT trim you should still be able to beef up those values. Does that make it overly rich?

 

Ya the problem is it works like a point graph style, connecting the dots.

73/110/160/290 are the increment points

So say I want to add a little fuel to the 110 column, if I add 6% fuel it raises 110 up the 6% but also slopes back down to the 73* column which would increase in the areas that dont need any adjustment!

And since Im running 17:1 @ 135*, I need to add 16% fuel to bring that to stoich, thats a big dip back towards the areas where everything is running good

Really hoping to just avoid/reduce the heatsoak that the sensor is seeing

There has got to be a way without relocating the sensor to right on the charge pipe

 

Well it interpolates so if you have 5% at say 100* and 10% for 150*.
It will calculate 7.5% for 125*. You want a gradule slope anyways.

 

Just curious, does it help to give it a little extra throttle when starting, and rev it a bit right away?

I ask since my Subaru has hot start issues as well, and just getting some extra fuel flowing through the injectors right away seems to help, as opposed to no throttle input and letting it struggle to idle. Never had any issues on my Honda, but it is still n/a for now.

 

lol can i join the club?


why not some nice looking hood vents?
bmw doesnt look bad with hood vents


something like this style

 

i have this exact same problem same injectors and s300, i have messed around with it and its either too rich at cold start and too lean at hot start i cant get it yet and its making me mad,

 

Hood vents dont work as the car is a daily and I would not like it to pour rain in the engine bay