16v Guru's...Lend me your ears! (Starting issues)

[c4ptiv3]

Ok gents. Got everything assembled and ready to go last night and we couldn't get it to start. Turns out the fuel pump wasn't coming on but we were getting spark.

Fast forward to this afternoon and we've found the relay bad for the fuel pump and jumpered it so we are now getting fuel, but no spark. Nothing else has changed and I'm at a complete loss at what to try next. We have checked all fuses and nothing has come unplugged, I unfortunately do not have a voltmeter at this time, but does anyone have any ideas as to what the hell would cause the spark to just stop?

16v w/ TVIS.

[c4ptiv3]

ok, went over to McKenney's and found a few grounds we were missing and got those connected. We are getting a very very very small spark now, and the fuel pump still won't fire up without it being jumpered, we tried 3 other relay's and still none of them are working. All the coil checks showed correct resistance and voltage with a voltmeter. Still not getting the crazy spark we were the night before.

We decided to check the wires on the ECU plugs to make sure that nothing had come out or lose and found that the Haynes' Manual, ECU pinout diagram on the ECU and the Harness are all different, so I don't know what the hell is going on. I will post a drawing of the difference shortly.

[c4ptiv3]

Ok here are the images.

The "bullets" are the blank spots currently in each plug of the harness.
The words with arrows is where the diagram on the inside differs from the Haynes Manual.



Here is the pic of the Hayne's Manual diagram.




any and all input is greatly appreciated.

[dr.occa]

Have you checked that your COR (Circuit Open Relay) wires are good and is completing that circuit when on? Do you know for a fact that you've got a good AFM as well?

[c4ptiv3]

Have you checked that your COR (Circuit Open Relay) wires are good and is completing that circuit when on? Do you know for a fact that you've got a good AFM as well?

Where is this COR located? The AFM was good and working when pulled from the previous running engine.

Any input on the 3 differences in the ECU pinouts? I'm thinking this might have something to do with our issues.

[c4ptiv3]

found a video of the COR clicking on youtube and noticed that the dash has 3 idiot lights when the key is in the "on" position, mine only has the Check Engine Light. I'm really starting to think the pinouts on the engine harness are wrong.

Is the COR supposed to click or no?

[dr.occa]

The COR should energize or "click" when the circuit is properly being completed.

In your drawing on the note paper, is that looking at your ECU pins or looking at the face of your harness plugs? Do you know what I'm trying to say?

[dr.occa]

This is the correct pinout for the US AE86 ecu:

image courtesy of http://www.Club4ag.com" onclick="window.open(this.href);return false;

[dr.occa]

I forgot to ask, now is this already a GTS or was this an SR5 swap?

[c4ptiv3]

yes it's looking at it just like the picture you posted. So it looks like I'm missing A/C(no big deal) and E21. What does E21 connect to?

I'm not getting any clicking from under the dash near the ECU and I didn't see any wire with the COR on it. I guess I'll have to dig around in there and see what I can find, sounds like the COR is bad or has a bad connection. The only relay I hear kick on when you turn the key to "on" position is the EFI relay in the fusebox.

[c4ptiv3]

I forgot to ask, now is this already a GTS or was this an SR5 swap?

SR5 conversion, done by the previous owner many years ago.


This is my 3rd (GT-S) engine. We replaced the engine harness and had to add a plug that connects to the engine harness on the dash harness side. That would be my only other concern since there were issues with the number of wires on the plug versus on the existing harness.

[dr.occa]

So it was already running before with a 4AG?

[c4ptiv3]

So it was already running before with a 4AG?

yes.

The engine harness was shot and oil was shooting out of the dipstick. Turned out they had spliced the dash harness and engine harness together, so I wanted to replace it all.

[c4ptiv3]

I found all the tech data on club4ag, and noticed e21 is "sensor earth" doesn't this connect to the COR? I'm missing that pinout on the engine harness.

[86boy]

check the grounds at the AFM there's 2 or 3 of them. I had an issue with the damn fuel pump as well... come to find out 1 ground wire broke somewhere in the harness. Just a thought to throw on the table and something to check. See if you can't get a multimeter and check continuity and just see if it connects back to the (-) post of the battery. I fought like hell trying to figure that out. Traced wires and check this and checked that. PITA.