Woohoo - Its alive, BUT...

[Bergerac]

Go to Start/Idle --> Idle control and set the Algorithm to Open Loop
You set your curve in Warmup/duty Steps.

Best way to find the idle setpoint to go to Canbus/Testmodes --> Output test mode - Idle valve and slowly close the ICV until the car stalls, your curve should stay above that point. Once you get you fuel and ignition right and and nice stable idle in open loop you can setup closed loop.

[Drscottsmith]

Weekend update...

Made the adjustments as recommended for the ICV to get the engine running at a simple idle. That worked!1 I now have control of idle speed using just the adjust screw on the throttle body. I do feel like I am not running on all 4 cylinders now that I have a decent idle.

I did a compression test as well as a leakdown just to verify nothing crazy was happening and both passed - all cylinders between ~155-160 and between 0-10% leakage.

I also tested the coils and injectors in test mode. I get a good spark on all 4 spark plugs. I also get all injectors to click in test mode.

When I start the motor though something is just not correct. I do have the injectors backwards in the sense that 1-4 are on the injector 2 circuit and 2-3 are on injector 1, but from what I can see that is irrelevant. Maybe I have a setting incorrect in the initial setup:

Capture2.PNG (90.72 KiB) Viewed 702 times

It does seem strange however that everything tests fine but the engine does not run well.

We'll keep on plugging away.

[cda951]

Do you have a camshaft position sensor? That is required to properly run individual ignition coils, and will also enable you to run sequential fuel injection.

Are your fuel injectors wired for batch-fire or sequential injection? I'm sure the answer lies at the beginning of the story, but I don't feel like scrolling all through the thread

[Drscottsmith]

Hey CDA -

I am batch fire. Injectors 2/3 are tied together (Injector Channel One) and 1/4 are tied together (Channel 2). They all pulse when in test mode.

I am using wasted spark, which I understand (read: thought) should be fine using the individual coil packs (LSx - from a 1999 Suburban).

I have the injectors paired just like the coils, but my understanding is the 1/4 coils HAVE to be on ignition channel one (since 1 is first in firing order) but for the injectors it does not matter? I feel like this is where the problem is, but I cannot find any setting that specifies which injector channel to fire so that it matches the coil firing pattern.

I am wondering if I need to change the injector staging setting from alternating to simultaneous, or if my REQ_FUEL is off. I did use the calculator to configure that.

[Tom]

Post a video of it running so we can hear it. You can use a timing light on each separate spark plug wire just to confirm it is firing, if you suspect some are not... (kind of like a noid light for the injectors).


p.s., decades ago, I had a friend do a bunch of work on the motor of his chevy truck. When done, the motor ran, but was lumpy and down on power and seemed sick. After doing a ton of diagnostics -- even changing points, floats, etc.), we finally realized he had two spark plug wires mixed up, so it was running on 6 or 8 cylinders. Pulling one plug wire at a time was the key -- when you pull the wire off a cylinder that is running right, the motor stumbles more, but when you pull the wire off a dead cylinder, nothing happens...

[Drscottsmith]

Ok here’s the latest video.



Also confirmed (you can see it some in the video) that each spark plug wire is getting a signal.

Thanks all for the continued support.

[Tom]

Did you try pulling the spark plug leads (or injector clips) one at a time to see if one or more cylinders are not firing?

[Drscottsmith]

Well I forgot so went back out and checked. Looks like 4 is suspect. Checked all injectors with noid and they are good. Replaced the plug wire on 4 with a spare and got this:



I was kind of surprised it would take any throttle at all.

Checked all the exhaust manifold temps as well.



I think I may have a running engine with a bad exhaust leak?

[Tom]

I think I may have a running engine with a bad exhaust leak?

That's what I was leaning toward when listening to that video. Hard to tell from an internet video, but if that exhaust thump went away, I'm thinking it would sound reasonably normal.

Trust you capped off the ISV side of that hose too? If that side is still uncapped, it would be letting in a lot of unmetered air.

[ealoken]

2000 rpm idle?
False air, stuck tb?

That "knocking" schould be gone when the engine i hot, might be stuck lifters.
Otherwise, check oilpressure by manual gauge, if that reads low, tap the oil anc open the filter for debries.