replaced ref sensors and harness but still experience no start at times. why?
08-28-2016, 12:45 PM
#1
Drifting
Thread Starter
Join Date: Sep 2001
Location: Massachusetts
Posts: 2,597
Likes: 0
Received 0 Likes
on
0 Posts
replaced ref sensors and harness but still experience no start at times. why?
I replaced the reference sensors about 2 to 3 years ago along with a new harness down to the dme and just replaced one of the sensors last week because for some reason one of the wires had a few nicks in the outer rubber that exposed some of the sheathed wiring. Over the past few years since having news sensors I have still experienced no start, no tach bounce situations sometimes. usually the trick is to disconnect the connectors and reconnect. What else would be causing this?
08-28-2016, 01:13 PM
#2
Wonder if the connection harness on back of the intake (where your DME side marries up to the sensor connectors) is playing a role? You mentioned re-seating the connectors here as allowing the car to start. Have you replaced this connecting piece at any point?
08-28-2016, 01:38 PM
#3
Drifting
Thread Starter
Join Date: Sep 2001
Location: Massachusetts
Posts: 2,597
Likes: 0
Received 0 Likes
on
0 Posts
Those connectors are brand new along with the sensor and harness.
08-28-2016, 06:11 PM
#4
Rennlist Member
If reseating the connectors works every time and is not just a coincidence (?) then there must be something wrong with one of the connectors. If you have brand new a LR or similar replacement harness and two new sensors, however, my guess is it's just a coincidence that the car starts after reseating, and the real cause of the no-tach-bounce-no-start is related to bad gapping of the sensor, dme relay, cracked solder joints in the DME. Next time it happens, take note of whether the boost gauge shows "1" when the ignition is on and the car is off. That will tell you if the DME/KLR is getting power.
08-30-2016, 12:32 PM
#5
I have just gone through this on a 86T for a customer, ended up being a issue with the DME, i even opened it up and inspected the solder joints and wasnt able to determine any failure points. but now it runs great.
Mark
Mark
08-30-2016, 03:35 PM
#6
Rennlist Member
I had a similar situation. Turned out my sensor was too far from the flywheel. Would give intermittent no start.
Best solution is to look at the speed and reference signals at the DME connections. Look for the voltage specified, in Clarks Garage page. You will want to use an oscilloscope for best results. Turns out the voltage from the sensors can be vary greatly with just a small error in the air gap, to the flywheel.
My case was about 0.020" too wide a gap, not much.
Best solution is to look at the speed and reference signals at the DME connections. Look for the voltage specified, in Clarks Garage page. You will want to use an oscilloscope for best results. Turns out the voltage from the sensors can be vary greatly with just a small error in the air gap, to the flywheel.
My case was about 0.020" too wide a gap, not much.