Resolved Another "Won't Stay Running"

[4G63510]

I know there are a million of these types of posts, but I'm not finding my issue. Here's the scenario:

I pulled my engine to replace the bearings and oil squirters due to low oil pressure at idle. The bearings weren't that bad, but I replaced them anyway since they had to come out to do the oil squirters. Yes, I did this without pulling the head. It was a pain, but at least I didn't need to resurface the head and replace top end parts in the process. The car ran perfectly despite the low oil pressure at idle.

After reassembling everything, the car will not stay running without throttle input. When it does stay running, it runs VERY rich and sounds like it's missing on a cylinder. Mechanical timing seems right and ignition timing seems right. It's tough to check on a RWD setup, but I can tirple check if someone thinks that's an issue. I didn't change anything else about the setup. Fuel pressure is "wobbling" around 40psi at idle but isn't surprising considering I have to crack the throttle to keep it running.

I have swapped the CAS, igntition module, coil, plugs, wires, and nothing seems to change. I took a log of the "idle" and nothing seems out of place. I do have a ECMLink log and a short video I can share if it helps anyone. I built the entire car myself including the wiring and it has run fine for 20k+ miles. I am stumped on this one. One odd thing that seems to be happening is that when swapping wires or even the timing light to various cylinders, the issue seems to jump around. It doesn't seem to be consistent on which cylinder seems to missfire.

I'm open to any and all suggestions. I'm stumped and I don't know where to go next. I'm considering pulling the intake manifold to see if fluid or something is in there. I'm also considering pulling the valve cover to see if a valve is stuck or something odd. I'm out of ideas at this point.

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[CrackedDSM]

What’s the TPS voltage/input like, and is your idle switch simulated or actually physically working?

Those two things fixed my issue. Along with fixing a broken wire on injector #2.

 

[DSMPT]

The first thing that came to mind is maybe you are installing the CAS 180 degree off. I would check the CAS notch position just for in case. Also should double check the mechanical valve timing.

 

[4G63510]

Thanks for the input. I will triple check those things, but none of that changed between installs.

The CAS was never removed, so it should have stayed in time. Also, if it was 180 out, it shouldn't run at all. I'll still check it along with checking the mechanical timing again.

The TPS should be working normally since it sees 4% open to keep it running. I do have a simulated closed throttle switch, but that has never been an issue. I will still check ECMLink to ensure it is set correctly to simulate that switch.

I checked the wiring on the injectors and didn't find anything. I also tried shutting off individual injectors in ECMLink and it didn't change how it was running.

The only other odd thing that is happening is I have an "oil leak" from my intake manifold that is dripping from the throttle body area. I have no idea where the oil is coming from. I used an endoscope to look in the TB and didn't see any oil. I pulled the IAC valve block off plate and there was no residue in there either. My thought is that maybe some oil got into the intake when I had the engine upside down to do the bearings. I would think it would clear out by now.

I did a compression check and all cylinders are similar in the 185 range. I put an endoscope in the cylinders and I didn't see anything out of the ordinary.

I feel like I'm missing something simple. The very first time I got the car running it wouldn't start despite everything seeming fine. It turned out I had a pin on the CAS that was pulling out when I would install the connector. With an issue like that, it would show up in ECMLink and I'm not seeing any readings like that. I have attached both the video of the rough idle along with a log for reference. The log was not from the section of video (I think).
Rough Idle Log

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[1990TSIAWDTALON]

Just a notation, a 4g motor WILL run if the CAS is 180* out, it just doesn't run its best. I have a 1990 GSX that needed a timing belt when I bought it (or when the seller approached me about purchasing it). When I got it all apart, we put a small set of cams (HKS 264/272's) so the CAS had to come out. When I took it off, I looked at it, and showed my son (who also helps me work on my DSM's) the location of the tab and the location of the notch and it was 180* out. It ran "ok" for being one tooth off on the timing and having the CAS out of phase. Just so everyone knows......it will still run, just not as good as it should.
Now onto your issue......I am with the others. Check mechanical timing up front, just to be 100% sure and make sure that your static timing is 5* BTDC.
Check for good grounds to the motor and ECU. Grounds are notoriously overlooked, so just be sure you have good solid grounds back to your battery.

 

[DSMPT]

Also, if it was 180 out, it shouldn't run at all

Not true. It runs but it does not as it should. It depends on your setup and tuning.

Edited : It seems Marty posted and mentioned the same while I was writing.

 

[4G63510]

I discovered my mistake. Despite using a cam gear alignment tool, it's not fool proof. It would put the intake at advance and exhaust at retard by at least a tooth. I'm not sure what this means at the crank, but obviously it doesn't run right like this

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The crank was lined up, and that's what I was focusing on. The cams looked "close enough", so I went with it. I still don't like the 2G crank timing marks.

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After I fixed my mistake, things looked better.

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Unfortunately, the timing marks on the Fluidampr don't line up correctly. It's off by close to 5*, so I did my best to time the car with this in mind. If the timing is off, then I can always adjust it.

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In any case, things seem correct now. Thanks for everyone's input. It's always nice to have another set of eyes on things even if you double check them yourself.

 

[We're on Boost]

Unfortunately, the timing marks on the Fluidampr don't line up correctly. It's off by close to 5*, so I did my best to time the car with this in mind. If the timing is off, then I can always adjust it.

Thanks for noting this. I haven't put mine on yet. Will have to keep this in mind for a careful check.

 

[4G63510]

Thanks for noting this. I haven't put mine on yet. Will have to keep this in mind for a careful check.

Double check yours. This is just how mine lines up. I have a lot of vairables in my build. I looked at it from every angle to see if I was doing something wrong or if there was another way to set it up. There are timing marks 180* from these as well. Not sure why.

 

[steve]

There are timing marks 180* from these as well. Not sure why.

Because the same sprocket can be used on both the intake and exhaust cams. You'll note if you look closely that the marks aren't exactly 180* apart. There are two differences, the first is one mark in in a tooth valley and the other on the tooth and the second is that referenced to the dowel pin the exhaust cam is advanced something like 3 degrees.

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[4G63510]

Because the same sprocket can be used on both the intake and exhaust cams. You'll note if you look closely that the marks aren't exactly 180* apart. There are two differences, the first is one mark in in a tooth valley and the other on the tooth and the second is that referenced to the dowel pin the exhaust cam is advanced something like 3 degrees.

I guess I wasn't clear. The Fluidampr has timing marks 180* apart. With the pulley keyed on the crank, one set is about 5* advanced. I don't see a way to use the other set. I assume it's for EVOs or something that has a different key or timing setup.

I get the cam sprokets. This is good info though and those who are unaware, a good thing to have in case you need to "borrow" a cam gear or something.

 

[DSMPT]

Double check yours. This is just how mine lines up. I have a lot of vairables in my build. I looked at it from every angle to see if I was doing something wrong or if there was another way to set it up. There are timing marks 180* from these as well. Not sure why.

Because you are using a cam gear lock tool and the Fluidampr has the timing notch a few degree off.

If you lock the cam gears by a lock tool, the timing mark on crank would be a bit off sometimes. This is because the head gasket is thicker/thinner than the original and/or the cylinder head or/and block have been resurfaced and/or your timing belt is stretched a bit and/or the gear teeth are worn by time.
And vice versa too, you would see the timing mark on cam gear don't line up perfectly sometimes if you set the crank timing mark, because of the same reason.

As for the dowel pin, the dowel pins wouldn't be at exactly at 12 o'clock, because what Steve mentioned above. But it's not a problem because the dowel pins are not a timing mark. Those are to tell you that you have the cylinder number #1 in compression stroke.

 

[steve]

I guess I wasn't clear. The Fluidampr has timing marks 180* apart. With the pulley keyed on the crank, one set is about 5* advanced. I don't see a way to use the other set. I assume it's for EVOs or something that has a different key or timing setup.

Yep, I didn't get that you were still talking about the timing marks on the Fluidampr Harmonic Dampener. Thanks for clearing that up.

 

[4G63510]

Because you are using a cam gear lock tool and the Fluidampr has the timing notch a few degree off.

If you lock the cam gears by a lock tool, the timing mark on crank would be a bit off sometimes. This is because the head gasket is thicker/thinner than the original and/or the cylinder head or/and block have been resurfaced and/or your timing belt is stretched a bit and/or the gear teeth are worn by time.
And vice versa too, you would see the timing mark on cam gear don't line up perfectly sometimes if you set the crank timing mark, because of the same reason.

As for the dowel pin, the dowel pins wouldn't be at exactly at 12 o'clock, because what Steve mentioned above. But it's not a problem because the dowel pins are not a timing mark. Those are to tell you that you have the cylinder number #1 in compression stroke.

I get that there might be some differences in deck height, but the belt itself should compensate for variations. The crank mark on the block lines up fine, it's the pulley mark that seems off.

 

[steve]

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This is a 7 bolt block block from a 2G, right?
Are you using the 2G Crank Position Sensor or the 1G CAS?
Is this crank trigger plate facing with the outer section up of down? I can't tell from the picture but it looks up which I think would be wrong and that throws the crank timing off.

 

[4G63510]

This is a 7 bolt block block from a 2G, right?
Are you using the 2G Crank Position Sensor or the 1G CAS?
Is this crank trigger plate facing with the outer section up of down? I can't tell from the picture but it looks up which I think would be wrong and that throws the crank timing off.

This is a 2G 7 bolt with a 1G head and CAS. The trigger plate is facing the correct direction. The issue has been resolved, but I still don't like how the timing marks are off with the Fluidampr. I might swap on a stock unit just to see if the marks are the same.

 

[steve]

Good to know you have it running well now.

 

[DSMPT]

the belt itself should compensate for variations.

I don't know what you mean but what I told you above were general things about the valve timing.
And as I mentioned at the beginning that the Fluidampr timing notch is off because of the cam lock tool and the Fluidampr itself.

Please refer the link below. You will get what I was telling you.

https://www.dsmtuners.com/threads/help-with-cam-timing-marks.544793/page-2#post-153898716