well today i grounded the pins that they told me to ground, thanks guys

but while in the process i found something really weird, pin 2D was REALLY cheaply redid, can you tell me what pin 2D is for?? what does it control so i can see if i can do something better than what they did, it looks really badly done and cheap too. thanks for the help, havent driven since i grounded so i will know if it fixed my hesitation soon

 

on the '86-'88 rex, the 2d is for the O2 sensor

 

o2 sensor, so it shouldnt hurt anything?? thanks

but the wire coming out of it was black, then about 6" up it was a really light grey color, and the wire is about 3x bigger than all the other AND it has a braided aluminum wire coming out and hooking up to a black wire with red bands on it, anyone know what this is, or is it normal??

 

well, just looked at the wiring diagram, the o2 wire is supposed to be grey, now the question is what is that black/red wire it has that piece of braided aluminum wire going to??

 

damn i forgot, also the only black/red wire i see on the diagram goes to the port air solenoid valve, i dont know, this could be causing all my problems lol

 

The oxygen sensor wire is a shielded wire. It has a center conductor that has a braided wire shield around it. When it approaches the terminal 2D, the y put a ground on the shield (thats the crummy looking ground you saw) and at that point the center conductor continues on to pin 2D and gets connected to the plug. The center conductor and the shield should never make contact. But you know that. EDIT: You should ground 2C, 2R, 3A and 3G. If you look at the EGI AND EMISSIONS CONTROL SYSTEM diagram, you see that the brown wire with a black stripe(86-87 models)is the ground for about seven or eight sensors like the boost sensor, afm, tps etc. That is why it is a good idea to add a ground to that pin 2C wire. Its not bullet proof becouse of all the mechanical joints (solder) for each sensor to this brown/black wire. Thats why you see some people only having success when they at first ground the boost sensor, finding that did not help, then going and adding a extra ground to the tps etc. In your book go to the section called CONTROL UNIT and you will see the outputs for eacn pin on the ECU.

 

where can i find out what to do on grounding the ecu,,a bad ground may have something to do with my problems

 

See this thread and the url by NZCONVERTIBLE: https://www.rx7club.com/forum/showth...threadid=68773 EDIT: That said, of the three cars I have only one has had a grounding problem. The LEMON car had multiple electrical problems, one of which was indeed cured by extra grounds on the brown/black wire. Seems some cars were dogged by electrical problems and others run like a champ.

 

ok, so that is just a ground wire?? i did ground 2C and i was looking at the wiring diagram last night and saw the 2R pin was a ground.

im gonna get a cheap camera today, take pics of which wires go where and post a How-To on this so its much easier for everyone else in the future

 

If you look at page 50-25 of the online 88 factoy service manual, you will see that 2R and 3A are spliced together somewhere in the harness. Its best to ground each individualy in my opinion. and its only an opinion. On my turbo car I had to splice the harness back together about where it crossed over to the engine from the firewall on the right hand side. The people who pulled the engine in the wreck yard had cut the harness in that area and the salvage car that I bought had had a fire that burnt the engine part of the harness but not the part on the frame. In that mess or area you will find a number of wires spliced together. I remember seeing several splices of black wires. There would be three going in and one coming out of a splice. Same with brown/black striped wires. I have no idea why I have had no electrical problems on that particular car. Should have, but don't.

 

I'm assuming you did the engine-firewall ground too right??

Another one which fixed my problems with my S-AFC is as follows

On the MAF and pressure sensor, there is the same ground wire- a brown w/black stripe. I used a heavier gauge wire, grounded both of those sensors together, and to the chassis.
It made a LARGE difference in smoothness for me.

 

well i know this is helping, because my redline hesitation is almost completely gone, ima redo all the grounds i did yesterday in a while, and take bunches of pictures and post a how to hopefully it will disappear after i ground this stuff better today