What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Pigeon-Rat - Opel gambler build

1966 Opel rekord mounted to 1990 Nissan pathfinder.
Overview Gallery Discussion
It’s pretty basic but if you have a temp gun you can shoot each exhaust manifold port looking for the cylinders that are not firing. They should be significantly lower in temp than ones that are firing.

Then it’s down to why are the cylinders not firing right. Weak spark or injector issue.
 
ZooMad75 said:
It’s pretty basic but if you have a temp gun you can shoot each exhaust manifold port looking for the cylinders that are not firing. They should be significantly lower in temp than ones that are firing.

Then it’s down to why are the cylinders not firing right. Weak spark or injector issue.
Click to expand...
So i had a chance to try this today. While setting the timing, I tried putting the timing light clip on all the other plugs as well. I got no light at all from #4,6. Inconsistent light on #2.
Also, the Temps on 1,3,5 were all about 500*. 2, 4, 6 were about 200*

The firing order on this is 12,3,4,5,6. Seems really strange that every other cylinder would have an issue.

Cap and wires look new, and the plugs are new. Wondering if I need a new distributor.
 
I’m not a Nissan guy, but it certainly seems you are honing in on the issue.

Blower or not, two holes with no fire and the intermittent third is going to run like crap.


I think if the even cylinders share the same injector rail, it still would have a spark. You would have seen that with the timing light.

I’m having a hard time tracking to a distributor if it’s not firing on every other cylinder. Even less with a new cap. That just doesn’t make sense for a failure mode.
 
kgblazerfive said:
Are 2 4 6 on the same fuel rail ?
Click to expand...
They are, but I just had all the injectors cleaned and cleaned the rail while I was at it.
ZooMad75 said:
I’m not a Nissan guy, but it certainly seems you are honing in on the issue.

Blower or not, two holes with no fire and the intermittent third is going to run like crap.


I think if the even cylinders share the same injector rail, it still would have a spark. You would have seen that with the timing light.

I’m having a hard time tracking to a distributor if it’s not firing on every other cylinder. Even less with a new cap. That just doesn’t make sense for a failure mode.
Click to expand...
I agree that a fueling problem wouldn't keep them from sparking, so I don't think that is the issue.
The thing is, it runs like crap, but honestly seems like it would barely run at all with 2 cylinders down.
Is it possible they are firing, but the spark is just too weak for the light to detect?

It doesn't make a lot of sense to me either, but the signal is obviously getting to the distributor, so the issue would have to be between it and the cylinders, right?

I may throw a distributor at it and see what happens.
 
centexk5 said:
Does it do a batch fire type thing? Like it fires each bank all at the same time?
Click to expand...
Not that I can see. looks like a typical distributor. There is a cam position sensor in it that may be doing something weird, but I don't really know.

Time to throw parts at it and see what happens.
 
It’s a single overhead cam per side so is there 2 cam position sensors? One per head?

The cam on that bank could be out of time but that wouldn’t keep it from throwing spark.
 
ZooMad75 said:
It’s a single overhead cam per side so is there 2 cam position sensors? One per head?

The cam on that bank could be out of time but that wouldn’t keep it from throwing spark.
Click to expand...
Pretty sure it's only 1 sensor, in the distributor. And yes single over head cam per side.

I just tried replacing the distributor. Now no signal detected on any of the ds cylinders. :confused:

Gonna put the old one back in and see if I'm back to my starting point.
 
So, put the old distributor back in, and it went back to the same. I could get a signal on 2, but nothing on 4,6.
Went and exchanged the new distributor for another new one, and no signal on 2,4,6.

Gonna pull the plugs now and see if anything comes from that .
 
Plug #2 on top, #1 on bottom.
It does look like #2 isn't firing.

20220723_165849.jpg
 
That bank isn’t firing for sure. What’s even weirder is having two new distributors not show any signal at all but the old one show something on 2. I’m stumped and don’t even know where to start.

Is there an HEI module or something in the distributor that’s causing issues? I don’t know Nissan systems, just wag at this point. Maybe the old distributor is worn out enough that the signal can get to it for at least one cylinder but the new distributors won’t accept it because it’s so weak?
 
Was doing some checking this morning and it seems like it’s usually cylinders 1, 3, 5 and not 2, 4, 6. But there seem to be a few things that cause this. Distributor, ecm, cam//crank sensor, and timing chain.
 
I took it back to the shop to see if they could make any progress with it, and not much. :(
He was able to verify that we are getting spark through all the wires, so it has to be a fuel issue for the misfire. It's a consistent misfire in cylinder #2. He was also able to watch the fuel pulse widths and after a few minutes the ecu starts increasing the fuel dramatically on all cylinders.

At this point, he's thinking that maybe the O2 sensor heater circuit may be the issue. Possibly the O2 sensors are getting cold and screwing up the readings, so the ECU thinks it's lean and starts dumping fuel. :dunno:

I'm going to try to verify that wire is good back to the ECU, then try pulling the injectors and moving them around. See if the misfire follows them.

Also, still having trouble with it holding idle. I need to trace the throttle position switch wire out to make sure that the ECU is getting the closed idle signal.
 
You must log in or register to reply here.

Latest Posts

Top Bottom