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No spark after breaking in IPD cam

Have you swapped your main system&fuel pump relay (the one by the EZK/ECU in 240s)? If you're not getting good voltage to the ECU/relay, then relay clicking and misbehavior may occur. (As soon as the ECU turns on the relay, the voltages can drop due to poor connections, the ECU gets lower voltage, resets, relay shuts off, and it all starts over again.)
 
I know the fuel relay is under the dash labeled B, I could take that out and check it out.

I?ve been searching for a main system relay. I?ve read about some white relay up by the drivers headlight, couldn?t find any relays there. I?ve poked around just about everywhere and couldn?t find this relay. Keep in mind, I?ve completely removed the AC and heater components, so access behind the dashboard isn?t terribly bad
 
You can find a 1990 760 greenbook on the Wayback Machine archive of volvowiringdiagrams.com. It looks like the main relay is 2/13 - greenbook pg 19 shows the location. I'd remove the relay and carefully inspect both the socket and relay pins to see if they look clean and good. If so, plug it back in and move on.

I'd also check the ground wires that go to front and back of the intake manifold. These are the ECU&EZK ground connections. If one of these is broken or making poor contact, weird behavior can result.

Edit: here's the link from the thread stickied at the top of this sub-forum. I assume you can figure out which directory and file is for a 1990 760:
https://web.archive.org/web/20180731041739/http://www.volvowiringdiagrams.com/
 
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I have found a couple places that list the Volvo Greenbooks as links, but it?s literally a list of EVERY greenbook, and they aren?t titled the best.

In regards to the 2/13 relay, my car is a 1990 760, I believe the relay is down by the hood release, with a fuse attached to the end of it. I have checked that fuse which was fine, but wasn?t sure what that relay went to, but after some searching I believe that?s the one. I?ll check it out, recheck my grounds, and post back
 
$10 test lamp. Get one, or you aren't qualified to do electrical diag.

Use a jumper wire to the starter solenoid. No wife/buddy needed. There's even a terminal on a 240 to connect 12v to. It's a yellow/blue wire
 
ZVOLV said:
$10 test lamp. Get one, or you aren't qualified to do electrical diag.

Use a jumper wire to the starter solenoid. No wife/buddy needed. There's even a terminal on a 240 to connect 12v to. It's a yellow/blue wire
Click to expand...

I’ve since got my qualifications!

Here’s the newest update, and a pretty significant one if I might add! I’ve found the ezk116 pinout for the connector online. I pulled out my test light and tested each pin of the connector with ignition on. If the pinout I found is correct, and I’m looking at the schematics correctly, i only have power going to pins 5 and 6, which is showing as 30v supply and 15v supply, respectively.

I’ve cleaned grounds throughout the engine bay, opened up the fuel pump relay to check its operation, and unplugged and cleaned the contacts in the two grey connectors on the passenger strut tower. All to no avail. I also found a yellow and brown wire that was almost completely disconnected from the positive battery cable. It frayed out of the ring connector.

Test light shows no injector pulse as well


Here’s another interesting point. I disconnected the white plug down by the ecu, right under the glovebox. Ignition on, probing with a test light showed about 10 pins that had voltage. Now on one of those pins when I touched it, the light lit up and I heard a relay clicked. Turns out it was the fuel pump relay, but only one contact was actually being pulled in; the one on top. Something fishy here or does this sound normal?
 
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The relay action sounds normal. It's a two part relay. One part clicks on when the key goes on. If it primes then the other side can go on for a second or so. But the second section only goes on steady if the ecu is getting an ignition signal from ezk.

So if your wiring tests good. Power to the ezk is good. Then it's usually either the ezk box is bad or the crank speed sensor is bad. they are the two things that make the rest happen.
 
Still need to do a continuity test on the wiring itself.

I agree that it sounds like the ezk or crank sensor, but both have been replaced.

If the wiring tests good, I don?t think I?ll have much a choice but to take it somewhere. I?ve been at my wits end for a couple days now. I?ve been researching different tests with a multimeter, test light, etc and nothing has come up
 
Resistance on the original sensor was around 240, the new (autozone) one showed 180, which is within spec of what I?ve read. Would a test light be an acceptable way of checking that the crank sensor is putting out voltage while cranking? My meter seems to not like reading really low voltage, especially in quick spurts
 
I clicked on the link, my meter just isn?t up to par unfortunately.

I do all the work on this car myself. I recently tore down an engine and replaced all gaskets, installed and fired up first try. Did the accumulator mod myself, installed a modified g80 (which I modified) all without issues. I?ve rebuilt my turbo, converted to a dual speed electric fan, converted to wasted spark. I don?t claim to know it all, but have a good grasp on what I?m doing. I know it might seem like I fired the parts cannon, but I had a lot of the parts already, so why not try and swap em?

I?ll agree that my diagnostics may not have been great, and that I probably overlooked something, but I don?t agree that the issue I?m having is caused by my
 
I?m not quite sure what you mean? I think you?re asking out of those 4, which is missing.

My problem seems to be getting voltage to get to the ezk unit. Pins 5 and 6 are getting their voltage with the ignition on, but none of the other pins have power going to them. And yes, my battery and terminals are all clean, and tight.

Last night I removed the dash as it was in rough condition, and as we all know hides all dem wires. I started to go through and remove any wiring that isn?t needed to pass inspection, and run. I am keeping the radio, power windows, and power locks. Once everything is removed, it should be easier to find any wiring problems. I?ve been planning on doing this for a little while anyway, this is just a good time to do it.
 
Electric sunroof has been ditched for a manual one. My heated, power seats have been ditched for manual, non heated one. Overdrive has been bypassed with the Ipd unit. All stock speakers have been removed. Power antenna removed. My clock doesn?t work in the gauge cluster, so that switch can be removed, along with a couple other switches. All interior lights. I don?t expect to lose a crazy amount of wiring in the grand scheme of things, but A) weight lost is weight lost, and B) even one wire completely removed is going to make my life easier, now and when it?s time for an aftermarket ecu because at least than I?ll have some hands on experience and have a better grasp on what gets power from where, and I can?t start planning on how I?ll be running the wires when it?s time to convert.

I don?t know why you have this idea that I do shoddy work. Have you ever even seen or heard from anyone about my work? Damn, can you even tell me what color my car is, let alone what type of work is being done to it?

Do you have a build thread for your car? I?d love to check it out. Maybe your car will inspire me to do better work on mine
 
What diag codes do you get from the OBD box after trying to start? Pin 2 is ECU, pin 6 is EZK. If you get 1-1-1's, at least the ECU/EZK are getting power.

Have you checked that you have coil power _during_ cranking? If the ignition switch is flakey, you might be losing power just during cranking. You could try starting it using the starter jumper connector in the engine compartment, shown as 17/1 pink in the greenbook
 
I?ll try again tonight to pull the codes and try the starter wire you?re describing

I have noticed something else strange, that goes hand in hand with another strange happening I?ve noticed/mentioned:
I?d mentioned that with the ignition on, all dash lights illuminate with the exception of the overdrive arrow. As I turn the key forward, just before it actually starts cranking, the arrow lights up and fuel pumps stop running. Now last night I noticed that I?d left my headlight switch on. When I turn the key forward, the headlights illuminate, but once I get to the spot where the OD arrow lights up and fuel pumps stop priming, the headlights go out. They stay off while I?m cranking.

With this in mind, a coworker suggested checking the alternator. He admitted that it sounds like that wouldn?t be the problem, but he?s seen cars simply die, crank strongly, and end up being the alternator.
 
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