View Single Post
sjf911 sjf911 is offline
Registered User
sjf911's Avatar
Join Date: Dec 2006
Location: Idaho
Posts: 5,727
Engine bay temperature data

Since going to a full bay intercooler I have been plagued with hot restart heat soak issues (lean running with misfire after restart for a number of minutes). There has been debate on the MS forums about whether this issue is related to sensor heat soak or fuel injector dynamic changes. So, this winter, using an add on IOx box, I wired in additional temperature sensors (thermistors) placed in front of the fan, in the IC core, on a fuel injector, and on the right hand fuel rail. This is in addition to a 3.2 CHT sensor, a Bosch CLT sensor in the engine breather cover, 2 GM open air element IAT sensors pre and post IC (the main IAT sensor), a Ford MAF sensor with an integrated IAT sensor (post IC), and a double ambient external temperature sensor (one for full time logging, the other switched with the main IAT sensor). I wired a relay to switch between one of the ambient sensors and the GM sensor post IC based on after start time and engine coolant temperature to cope temporarily.

The top photo shows the primary IAT sensor (MAT) in a weld on bung on the piping to the throttle body. The lower pulls back and shows the MAF (Ford blade style) in the outflow from the IC and the IC core sensor wire laying over the IC.

The top photo is the homemade double sensor shown installed in the lower photo behind the bumper.

The "ambient" engine bay temperature sensor and pre-IC IAT sensor (bung on the "up pipe").

There are 2 sensors here, one on the rail and the other on the injector shown before wrapping.
Sapere aude
1983 3.4L 911SC turbo. Sold

Last edited by sjf911; 05-18-2013 at 10:10 PM..
Old 05-18-2013, 09:31 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)