Why would VREF drop from 4.96 to 4.85V
#1
I only have 1.3liters
Thread Starter
iTrader: (2)
Join Date: Mar 2006
Location: Manchester, TN
Posts: 816
Likes: 0
Received 0 Likes
on
0 Posts
Why would VREF drop from 4.96 to 4.85V
I have a S4 TII with a 1987 TII ECU. The car runs fine when it first starts, but after reving once, my VREF voltage and all the associated sensor drop by .1v and it runs like crap. Why would the output voltage drop.
#2
rotray 70..
Join Date: Oct 2006
Location: Osaka, Japan
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
if you don't touch the throttle does this still happen?
are you measuring VREF off the TPS?
MAP Sensor will have a VREF as well... only those two places I can think of on a toyota engine, not sure about 13b.
are you measuring VREF off the TPS?
MAP Sensor will have a VREF as well... only those two places I can think of on a toyota engine, not sure about 13b.
#3
I only have 1.3liters
Thread Starter
iTrader: (2)
Join Date: Mar 2006
Location: Manchester, TN
Posts: 816
Likes: 0
Received 0 Likes
on
0 Posts
If I fire up the engine and let it idle, the VREF at the ECU connector reads 4.96v. After I rev it once, the voltage at the same connector drops to 4.85v. My signal from the TPS in turn drops from 1v at startup idle to .85v at idle after reving once.
#5
HAILERS
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
Posts: 20,563
Likes: 0
Received 21 Likes
on
19 Posts
Originally Posted by 85rx-7gsl-se
If I fire up the engine and let it idle, the VREF at the ECU connector reads 4.96v. After I rev it once, the voltage at the same connector drops to 4.85v. My signal from the TPS in turn drops from 1v at startup idle to .85v at idle after reving once.
Remember, when you set the TPS to an output of one volt, the engine needs to be fully warm/hot due to the thermowax/fast idle cam/etc.
Thread
Thread Starter
Forum
Replies
Last Post
Turblown
Vendor Classifieds
12
10-17-20 03:25 PM
FC3S Timmy
2nd Generation Specific (1986-1992)
16
10-03-15 01:08 AM
pfsantos
2nd Generation Specific (1986-1992)
1
09-30-15 01:29 PM