That is good information on how to correctly solder wires. In my youth I bought Heathkit's and built engine analyzers and stereo systems. Then in 2008 I repaired the wiring harness on a BMW motorcycle that had shorted out the electrical and burned all the grounds and the wires laying next to them in the harness. that gave me many hours of relearning my soldering technique. Then along came the C4 and somebody before me must have just grabbed wires and pulled on them. They were pulled out of the connectors and broken etc. So there I was with the harness in my lap going wire by wire and splicing and heat shrinking until I was blue in the face. I will admit that I may have gotten sloppy at times if I got tired or my sugar was off. So that is why I am just as a precaution going to look over the repairs I made to be sure I don't have a wire about to come through the heat shrink. Your explanation of what a cold joint is verses a hot joint should be a sticky for future enthusiasts who try to repair a wiring problem.
The frustrating thing about cold solder joints is that they will carry current just fine. For a while. But once the copper wires start to oxidize underneath the solder, then the connection can become intermittent and vibration sensitive. Which then becomes an absolute nightmare to try to troubleshoot.
For circuit boards, this can happen fairly often because the wave soldering being used for an entire circuit board at a time just does not get the component lead surfaces hot enough to melt the solder. So the solder will flow around and onto the leads, but does not actually form a soldered bond. When that happens, quality manufacturers either re-run the entire batch, or scrap them all as salvage for component parts. The unethical ones will put them into the products anyway and hope the problems don't start showing up till after the warranty period has expired. This happens sometimes, yet you NEVER really hear about electronics products being recalled, now do you?
Heck, I remember having an entire batch of bad CPU cards and I fixed them by manually reapplying heat to each and every solder joint. The company I worked for was ready to scrap them, so I figured there was nothing really to lose. I actually got a Christmas bonus that year.
I took the car out yesterday for a 45 minute test drive. I monitored the IAT signal with EFILive on my laptop, and the signal was stable at around 77 degrees. Pretty interesting to note how effective the STS intercooler is at keeping the incoming air temperatures pretty close to ambient. So that particular problem appears to be fixed.
I didn't push the car any at all, as I was just checking it out to see if any strange noises cropped up, or if anything would fall off the car because I forgot to tighten it down. Also kept an eye on the fuel pressure gauge to make sure none of the new hoses wasn't coming apart on me. Plus I had that new Heatshield insulation on the back pipes and the tunnel plate area.
Actually the car drove really well. Didn't even hear that scraping drivetrain noise I had been hearing before. I'm hoping it's just the clutch taking longer than anticipated to break in fully.
And I had the camcorder running just in case there was any sort of catastrophic failure that I could at least have it on video. But no failures, just a pleasant drive down through Crawfordville the long way, and back again. So yeah, this is a REAL boring video for most people, but it's been a while since I've done such a video, and I'm just darn glad that this is pulling all together to where I will finally have a driveable car out of this. The car pretty much drives like stock, but I'm just barely pressing on the gas pedal. It feels like there is quite a beast lurking underneath the pedal waiting to be released.
I'm using a remote microphone in this video to try to eliminate some rattling noises I always get using the camcorder's internal microphone. This one is better, but there is still something apparently rattling near the microphone pickup. It's just distracting when I'm trying to listen for abnormal CAR noises while viewing the video.
I put the wideband back in late yesterday, so if the weather behaves, I want to do some more logging so I get more familiar with the EFILive scanning process and what all those squiggly lines mean. Still going to be a while before I feel confident enough to actually do any tuning changes on the car. But all in due time...
Oh yeah, I got a box of goodies from Heatshield today (thanks Steve!) so I'll be able to insulate the remainder of the exhaust system over the next few days. The insulation I put up on the back pipes help up very well, and I noticed quite a difference in temperature between the covered and uncovered pipes. So yeah, GOOD stuff.
I noticed how nicely it idled down on the dirt road it seems very docile at low RPMs. Have you been able to get it out on the open road and cruse along at 70 for any length of time?
I noticed how nicely it idled down on the dirt road it seems very docile at low RPMs. Have you been able to get it out on the open road and cruse along at 70 for any length of time?
No, not yet. There are some open country roads around here that I would cruise at a steady 55 to 60 mph, though.
It will still on occasion surge at low rpm levels, but that is normally only under 10 mph. So it's no big deal. I would like to work on the startup because it doesn't catch as quickly as I think it should, so that seems to need some work. But I've got to get more comfortable with what I am looking at in the log scans before I want to meddle with anything in the tune. I really don't like to work in the mode "let me try THIS and just see what it does." I would rather do "well I need to do THIS, so THAT should fix it." But that just might not be attainable, as that sort of specific info seems to be hard to come by.
I took this video after I had put the exhaust system back together again and put sealant in the expansion slits in the slip over ends of the joints. I checked for air flow at the joints using a Q-tip that I pulled the fibers away from the head so any air flow at all would cause movement of those fibers.
Looked like I had fixed the exhaust leaks.
BTW, the engine is running a bit rough because of the IAT sensor problem. This video was taking before I fixed the shorted wire I found. The sensor reading was pinned at max telling the PCM that incoming air temperature was 284 degrees. So timing and fuel were pretty whacked as a result as the PCM tried to compensate for what it thought was excessively hot air coming into the engine.
Made some minor changes in the fuel injector tables today, so I wanted to run the car to see what, if any differences they made. I got a new injector table spreadsheet from Jon at FuelnjectorConnection.com so I transferred this info over into the EFILive tables.
Startup idle seems smoother, and the car seems to run OK. Didn't see any noteworthy differences, either pro or con, but this was a very minor change to the tuning. The reason I wanted to make the changes was because the tune in there was using both the vacuum mapped fuel pressure regulator as well as the IFR (Injector Flow Rate) table to control the fuel flow calculations to the injectors. I can see where this arrangement could be used to more finely tune the injectors, but everything I've read suggested that picking one method or the other is preferred. So at this point, I'd prefer keeping it as simple as possible.
I did note that the long term fuel trims were working harder because the engine wanted to run richer than necessary, but they compensated nicely to keep the AFR in the ballpark. Mike Carnahan is looking at the tune for me now to make some changes to even the AFR out so the fuel trims don't have to do that so much.
I was logging data while idling and driving the car, so I got on a deserted stretch of road and pushed it into boost a bit to get into a higher rpm range for the logging data. It didn't take much to get 'er moving! I was in third gear and didn't crack the throttle position past 45 percent and only hit 4600 rpm. Matter of fact the log shows me that boost and rpm was increasing while I was actually gradually reducing the throttle position. It was spooling up FAST! Just keeping the throttle only at 45 percent would have probably been spinning the rear tires before I knew it. There was a LOT of acceleration going on then. I didn't even look at the boost gauge because my eyes were glued to the road.
But in any event, things looked pretty good in the logs and the car drove really well. Didn't hear any signs of that drivetrain noise again this time, so that was a good sign.
Anyway, here's the obligatory boring video.
Oh there was one problem noted. When I got the car back home, I put it on the lift and inspected it thoroughly looking for any signs of problems. Nothing underneath, but when I looked underneath the hood when the car was back at ground level, it looks like the airbridge popped at the lower coupler while under boost.
You can see where the airbridge apparently ballooned out on the side at the coupler but went back to it's normal shape after boost ended. At least the airbridge didn't pop like a balloon, as I've heard they can do.
I repositioned the clamps a bit, but I'm thinking this might be a continual problem with this flimsy plastic air bridge. Once they get hot, they become way to pliable and I don't think the clamps can hold them very well because the plastic becomes too soft. Not exactly sure what to do about it at the moment though. I'd like to be able to find a metal fabrication outfit that could take one of these plastic airbridges and make me one out of aluminum or stainless steel using it as a template. There really aren't a whole lot of options out there for STRONG airbridges for forced induction, it seems. Or maybe there is some sort of epoxy coating I can put on the plastic to strengthen and harden it so it won't go all soft and squishy when it gets hot. The incoming air temperatures didn't go over 73 degrees, so if I could insulate the airbridge itself adequately from the underhood temperatures to keep it from getting hot, that would probably help quite a bit.
Otherwise I'm going to have to be thinking about a new hood that can clearance that BBK aluminum airbridge that I originally had on the car. But that is just not in the budget at this time........
On the air bridge could you get some aluminum roof flashing and wrap it around the plastic air bridge and fasten it on the plastic using jb weld and some pop rivets at the seam of the aluminum. That might be a way to stiffen it up.
On the air bridge could you get some aluminum roof flashing and wrap it around the plastic air bridge and fasten it on the plastic using jb weld and some pop rivets at the seam of the aluminum. That might be a way to stiffen it up.
Heck, I'm open for ideas right now. JB Weld doesn't work too well with plastics, though, as far as adhering to it goes. But I'm wondering if something similar could be painted over the outside of an airbridge that would harden off and be like an armored covering. Only problem is that those airbridges, although only plastic, are not inexpensive to be experimenting with very much. So I need to find something I can use as test subjects first. Maybe plastic bottles would work?
Another thought on the air bridge. Get some fiberglass and resin and wrap the air bridge with it. I think they have small kits of fiberglass at the auto parts store
Using a 2 litre bottle to experiment with is a good idea. At the cost of new hood or air bridge a couple of experimental trys is cheap.
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