ok 2k on a reman motor and outta nowhere right at 3800 when the secondaries come on it just sumbles n stutters so i had a tech say its cuz a melted harness..so trying to save the harness i cut it open n find prolly 5 wires melted so they were flat.. so i replace the melted sections n solder in new wire.. but still to no avail.. and the car makes a high pitched whistle also.. i have no clue what could be wrong..wondering if they injectors just puked or connectors went bad..ecu.. i have no clue.. does ne one know what harness wire is for the 2ndaries??? ne help is appreciated thanks

tim..

 

you have the dreaded 3800rpm hesitation. There is alot of different approaches to fixing this problem. In my experience of curing this problem on a number of cars, you have to reground the ecu. If you have a copy of the FSM it will tell you which pins at the ecu are grounds. Sorry if I had my books in front of me I would tell you which ones. Add new grounds to all of the ground points at the ecu and your problem should be solved.

 

hmm never really thoughta that..

 

its not really like a hesitation its more like a total misfire

 

just regrounded the ecu and still no help.. arrrrrr

 

How?

 

use a 12g piece of wire with ring terminals from the battery to the tranny bell housing where the ground for the ecu is

 

The ground wires for the ECU are on top of the rear rotor housing. The ground that goes from the wiper mount area to the transmission bell housing is not the ECU ground.

 

then whats the overly large wire thats grounded to the tranny bell housing behind the plug wires?? ur talkin bout the bolt that threads right behind the rotor housings under the throttle body correct?

 

No. I'll see if I can jpg the top of the rotor housing on the scanner in the next hour or so.

The ECU has grounds for the internal electronics in it plus the grounds for various solenoids/sensors. The harness that goes from the ECU to the injectors and the solenoids and sensors is called the EMISSIONS HARNESS. The emissions harness is noted on the schematics with the letters EM next to the connectors. The FRONT harness has the letter F noted on the schematics. The ENGINE HARNESS has the letter E next to the connectors shown on the schematic.

In the FSM there is a section in the FUEL section called CONTROL UNIT. It lists each pin on the ECU plugs and their function in life. Pins 2R, 3A and 3G are the main ground wires for the ECU and they terminate at a ground that has a reference designator called/numbered 24. Twenty four is located on top of the rear rotor housing, just a couple of inches to the left of centerline. There are only two wires on this ring terminal. The wires from 3A and 2R are spliced together prior to reaching ground number 24, that's why you only see two wires at that point instead of three.

Look at EGI AND EMISSIONS CONTROL SYSTEM schematic and you'll see that. All the ground points on the car are shown in the schematics. There are approx 27 ground points on the car and all are shown on a page called JOINT CONNECTOR AND GROUND CIRCUIT. The FSM is written on an eighth grade reading level so anybody on this forum can understand them. They are free downloads of the fsm available on the web.

 

The EMISSIONS HARNESS has a ring terminal with two black wires that connect/bolt to the area shown on the jpg. I didn't feel the need to connect a harness to the jpg'd rotor housing.

 

so in otherwords ur telling me to reground the wires that are on the harness that connect to the top of the rotor housing as ur picture shows

 

No. I'm saying that if you want to check the ground wires for the ECU, those are the ground wires for the ECU. No more, no less.

It'd be easier to just pull the plugs off the ECU and ohm out the ground wires to see if they have a good ground or not.

 

ahhh ok now im startin to understand..and if the grounds are good would u have ne other sugjestion on where to go from there?