Car is haunted, sounds like 3 cylinders

[desolateboosted]

Ok posting on tuners!

The car will not stay alive, and sounds like it's running on 3 cylinders. I have to give it gas for the car to stay alive. If revved up it sounds like a subarau motor. If rpms drop to around 1k the car bucks, misfires and wants to die. Also sounds like it has the biggest cams in the world at 1k. Cams are fp3x and they idle like stock. I've swapped parts to try and pin point the problem with no success. The car is a 99gsx, 2g, 2.4 swap, fp3x, black top cas. It has driven fine for a long time with the mentioned setup, so anything regards to wiring is good and should be correct. Just a few days ago it has become haunted.

Small mod list:
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99GSX, 4g64 2.4L, Eagle Wiseco 8.8, FP3x, JMF Race Intake Mani, FP3065, 1250cc, Twin Walbro, ACT2900, AEM Uego Wideband, AEM 5.2bar

Things replaced/swapped:
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1. Coil pack
2. Transistor pack
3. spark plugs
4. spark plug wires
5. Injectors back to 450cc
6. Checked 95/96 cas box in dsmlink (also made sure spark wires were in the correct spots)
7. swapped ECUs
8. CAS
9. Injector resistor pack

-tested four injectors for continuity from plug to ecu (good)
-tested transistor plug for correct signals (good)
-tested for fuel with hose into bucket (good)
-tested for spark, rotated cas by hand (good)
-tested injectors, rotated cas by hand (good)
-took valve cover off to check: rocker arms/lifters,cams (good)
-tested camshaft & crankshaft wires for continuity from plug to ecu (good)
-spark plug wire firing order is correct
-checked ecu connectors (good)
-rotating cas 180 degrees does nothing

Notes:
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-almost no vaccum, maybe 1-3hg at 1k rpms
-compression test results: 180, 175, 170,170
-pulling maf sensor to run in dummy mode does nothing


If I try to keep the car alive around 1k (bucking, misfiring badly) the wideband will read all the way lean. It sounds simliar to running on 3 cylinders. Compression test is good with 180-170 across (did it twice just to make sure). Due to the lean condition I assumed one of my injectors were stuck/not working so I reverted back to the 450s, however that did not change anything.

Im puzzled now since swaping parts on the list above 99% of the time usually fixes any misfiring, bucking, studdering issues besides mechanical.

Videos:
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YouTube - VIDEO0090.mp4 - Engine Bay Video


YouTube - VIDEO0092.mp4 - Dash Video
Here's a vid with the stock ecu (it behaves the same as on the ecu with link). I'm holding the gas once it starts at around 3k rpms. The car sounds decent at those rpms, however, those rpms are so high it masks the problem until the revs drop to 2k then 1k. Half way through the vid you can really see how the car is behaving as the revs go up and down. Watch the wideband as the rpms drop. It goes dead lean when the rpms drop. At the very end you hear 4 puffs of air out the intake mani.

 

[hereitcomes]

Has your base timing moved at all? I didn't see that on your check list (which by far was one of the most intricate on this site).

I ruled out any sort of boost leak once I saw you had a GM.
I shall continue to watch the video(s) and ponder this with a drink. Yes. A drink at 8 AM.

EDIT: Did it start this after sitting, or randomly after driving/shutoff/re-start kind of thing?

 

[desolateboosted]

Base timing is good. Moving the cas timing doesn't net any positive results. The problem started shortly after a HG job. The car ran fine for a few days then just began to act like this.

Here's another video. It doesn't really want to start. Why is it back firing into the intake mani like this?

YouTube - VIDEO0093.mp4

Don't mind the transistor pack, the white wire was cut for the ARC-2, but it's temporarily wired into the stock configuration. It's running straight stock no ARC-2 connected to diagnose this ****.


Ok I got it running, but very poorly. It's the longest I've been able to have it running. Here's a vid of the dash. I don't understand how it can idle this low (300-400rpms max on fp3xs), but it does. It stays lean until I rev it up to about 3k. The wideband bounces up around 13-15afrs around 3k. It also revs up like it's misfiring the entire time, or running on 2-3 cylinders until 3krpms. How can I diagnose this? Mechanical or electrical? Electrical seems to be working fine. If I pull the spark plug wires it will arc to the head. All four do that so they should be fine? Then using a noid light to test the injector plugs results in lighting up as well. Must be mechanical then? Help...

http://www.youtube.com/watch?v=JWn5A_JjQ0E



Ok with the timing light connected it hovers around 5-10 degrees advanced at the idle rpms. I also tried changing the firing order and the car wouldn't start.

Here are two videos in order that show me pulling the plug wires one by one. When I pull the 1 & 4 wires the engine doesn't change in behavior, but if I pull the 2-3 wires the engine changes tone and sputters harder/dies. If I pull both wires out is the arc sopposed to stop? The arc stops when 1&4 are pulled. As soon as I put one of them back in the arc resumes. I'm assuming that's how the spark system works? If so I am getting spark on all four.

http://www.youtube.com/watch?v=rRJdkPZC_CU Video1

http://www.youtube.com/watch?v=vvfzraAbyLE Video2

 

[desolateboosted]

Ok here's a video of trying to start it without the intake manifold. It's not sopposed to start like this since the intake manifold is missing along with the throttlebody, so I would assume if it starts the engine would free rev to as high as it can go. But for diagnostic purposes this is how it looks like. I get 6-12" flames out the intake ports from doing this. It also happens in every port. What does this mean? Are flames sopposed to shoot out like this? Does a typical dsm do this? That is the question...

YouTube - VIDEO0004

 

[MIdsm]

With backfiring like that i would assume that the timing is off. Did the cam gear slip on the cam? Did your crank damper separate?

 

[Bluefire16]

This may be silly to ask, but you are sure you have the correct firing order? I mean, i had a similar problem, and left me stumped for a whole day. I pulled my downpipe off, and started checking everything (i did a turbo install and car wouldnt stay running)

Then realized i simply plugged in one wire incorrectly. The firing order can make a huge difference.

 

[desolateboosted]

With backfiring like that i would assume that the timing is off. Did the cam gear slip on the cam? Did your crank damper separate?

Timing is correct. I checked it and double checked it. I thought it would be wrong but it's correct. Crank pulley is fine as well. Something definately is wrong however...

This may be silly to ask, but you are sure you have the correct firing order? I mean, i had a similar problem, and left me stumped for a whole day. I pulled my downpipe off, and started checking everything (i did a turbo install and car wouldnt stay running)

Then realized i simply plugged in one wire incorrectly. The firing order can make a huge difference.

Firing order is correct. If I change it the car won't even start. With the coil pack changes, I made sure the firing order was correct.

 

[hereitcomes]

Your vac is low. When the car is held at 3k it is significantly more, but the car also runs fine.

I think this is a mechanical problem. Electrical doesn't really care about engine speed and things of that nature. If it is going to work, it is or isn't. Electric items can short and cause intermittent problems, but I believe we can rule this out in your case.

Have you checked the coil pack? I would resort to the basics of the motor. Install a stock FPR and make sure your spark is still in order (which it seems to be). This will be a good way to render working things are not the culprit. If this doesn't do anything, I think something is up with your cams.

 

[desolateboosted]

I have good news! The problem went away! I was just fed up and decided to put everything back on to test. After starting it I figured it would still stutter, but nope, it started up and within a few seconds the car returned back to life! Not really sure how it sorta "fixed" itself but everything seems to be normal (because it looked normal to begin with, odd...). Thank god.

 

[hereitcomes]

I'm glad it was resolved. Did you pinpoint something specific?