OK, tried to start it up this weekend. No luck.
After charging the battery, I put gas in the tank and turned the key.
On the positive side, the fuel pump kicked on, the lines pressurized, no gas sprayed on the floor and I saw about the right pressure at the rail.
On the negative side, turning the key only made a ton of relays click, and the solenoid kick out. I didn't hear the starter spin, and the engine definitely did not turn over. The gauges were wandering all over the place too.
My assumption is that the alarm I removed needs more removal. The wiring harness is certainly all hacked to pieces, so maybe I should spend a little more time on that. I can tell I've got a parasite somewhere, because the battery goes flat pretty fast.
Any suggestions for how to systematically troubleshoot shorts and parasitic voltage consumers? I'm also not quite sure how to tackle redoing bad bits of harness. Is it better to run all new wires, or just splice in sections? What's the best way to splice in a section? My soldering isn't so hot, but there's no better incentive to improve
Of course, when I got the oil pressure to come up a couple months back, the starter would turn over, so ?? I better get out my wiring diagrams
I've tried again, this time with a fully charged battery. The gauges look fine now, the lights come on, but turning the key only gives a single loud click and then no electrical.
I suspect I have some part of the alarm system left in
The easiest way I've found to resolve a bigish power drawl is to begin with isolating it's location. Use a voltage and begin pulling fuses one at a time. When the voltage increases substantially, you have an idea where to look.
Alternators have been an issue on every car I've owned.... (Either the internal regulator stick on and drains the battery)....
My MR2 had a very strange issue where the Diode went bad and backfed the battery shorting it out at the alternator. This was 10 days after acquiring it.
In reply to dansxr2:
That's a good idea - I like the systematic approach, because omg, the wiring harness is:
1) complicated
2) hacked on by alarm hacks
3) hacked on by a rank amateur (me)
In other news:
I figured out the no start issue. I measured the battery voltage (12.8v), but while I was doing that I noticed that if I shorted the positive terminal to the positive battery lead the lights turned on. I sanded the lead and presto, a startup! \m/
Still have a voltage drain...
https://www.youtube.com/embed/CxKmAlLFar8
The motor is pretty damn rough and putt-putt-y. It feels a bit like it's only firing on a couple cylinders.
I appear to have good oil pressure. I believe I've connected the plug wires well and in the right order. I'm not seeing any obvious head gasket issues. Why might it be running like a washing machine? How do I check to see if I've got a dead cylinder?
After this long (almost 4 years to the day) that definitely counts as a win!
In reply to Crackers:
That's just on this forum... It's been close to 9 years. Survived two moves, one of which was cross country.
I recollect mothballing it for a reason, but why? It was running poorly then. I feel like perhaps it overheated?
I'm not sure anymore. That would explain why I remember being worried about the head gasket and oil cooler seals.
I've done some diagnosis and I think the trouble is a bad fuel pressure regulator. Fuel pressure is sitting right around 50psi with the engine off or running, and it leaks down very, very slowly now that I tightened up all the connections.
I let it run a little longer and the lifter clatter quieted down, which is heartening. The rear cam tower gasket is leaking like a sieve. Not entirely unexpected, but smelly on the headers. I think that's only replaceable by pulling the cam tower, which I don't really want to do
Time to throw some parts at this
As a younger kid I believed that the only "real" Porsche was a 911 or at least had to be rear-engined.
I'm developing a real appreciation of these 944's and other models.
In reply to ebonyandivory:
Popup headlights forever!
Plus, you can put a full set of spare tires in the hatch
I installed the new fpr, and figured out why the cam cover is leaking. It needs 4 bolts; it has 1 bolt.
To the bolt store!
Apparently the cam cover has 4 bolt holes, but only takes 3 bolts; the engine lifting ring covers one of them. I checked Clark's Garage and the factory manual and they both agree, so 3 bolts it is.
I also opted to make my own gasket and use ultra black to seal it - not exactly Porsche procedure, but Porsche procedure leaks like a sieve, so I can hardly do worse
I put the new fpr on and fired it up.
The good news is that my fuel pressure is bang on spec. 36psi with engine off, 29 with engine idling. The bad news is that it still runs rough.
I pulled the plugs, which are brand new, and 1&2 were clean as a whistle, while 3&4 were pretty sooty. I checked the spark, and the tester lights up for both 1&2, so I believe they are getting zapped. I double checked the timing belt and the marks all look like they line up.
That leaves fuel and compression. The injectors are freshly rebuilt, never fired since sending them off. How shall I go about testing them?
I attempted a leakdown test a page or two ago, but my technique may be off. Any internet advice for me?
Back to this - I've been thinking and waiting on some parts.
I believe I've got it running on all 4 cylinders, but it's still pretty rough. My current theory is that the motor mounts are bad.
That's not quite a theory - I know the motor mounts are bad, the theory is that they are so bad that they explain the unbalanced washing machine feeling. I ordered new mounts and hopefully this weekend we shall see if they improve matters. I went back and forth on what kind of mounts to get. Consensus is that the Porsche mounts are best; they're also like $500. Knockoffs supposedly decay rapidly with heat exposure. I decided to gamble a little and split the difference by getting Lindsey Racing ultra mounts. The rubber looks rebuildable if they crap out on me.
While I was waiting for everything to get shipped up here, I rebuilt the throttle body with the Arnnworx kit. Pretty straightforward, just popping in o-rings. The butterfly valve shaft o-rings were dust when I removed them, so maybe I'll get a better idle.
I've got a fair amount of oil in the intake. My assumption is that my AOS is clogged, which is pretty common on 944's. I think I'll just sponge it out and let it be for now.
My air screw was 4.5 turns out from fully seated. That seems in the ballpark, right internet?
If you think you got it running on all 4, why don't you unplug a spark plug one at a time to see if it gets worse?
If it gets worse on every plug you know it's at least running on all 4 albeit poorly. The motor mounts aren't a bad start and make sure you don't have a vacuum leak somewhere.
In reply to crankwalk:
I did that, and it got worse when I unplugged each cylinder in its turn.
I've got a dumb question on that front - are you supposed to unplug a cylinder while it's running or while it's stopped. Seems like while it's running is asking for a zap.
Vacuum leaks are something I'm looking at. I replaced all the little hard lines with silicone lines, so those are probably ok. I also have a new j-boot, so that's ok. The rats nest under the intake is original, oil and grunge caked, and probably not ok. Debating on how much I want to get into that. While I have the TB off, I can get at about half the rats nest, but to do it right I should probably pull the intake. That would also give me the opportunity to reposition a heater control valve that's a little awkwardly placed over the clutch.
Alright, worked up the gumption to get half way through motor mount replacement. I've got the old mounts detached, now I just need to lower the cross member a bit and squeeze the new mounts in.
I'm pretty sure I've got original mounts, because they are what Clark's Garage (itself no spring chicken) calls "old style mounts". They are a pain, because they use a nut on the upper attachment point, rather than just threading the mount through hole.
Old mounts are definitely bad, but we'll see what it feels like as soon as I get these new mounts in.
I'm a bit limited on garage time - mostly just when the toddler is napping or I feel like sacrificing a couple hours of sleep myself
Might as well include a picture of the new mounts before they go in the car. I get about 30min in the morning before the circus wakes up... Today I undid one more bolt
Tomorrow, if all goes well, this might be going in
Got one in there this morning:
Hopefully I'll get the other this evening so I can torque everything back down. These are clearly meant to be installed on the crossmember before the engine...
I drove one of these daily for 6 years with collapsed motor mounts. What was odd is that it never got any worse over the course of 50k miles and probably 20 autocrosses. The other 944 guys' mounts would get way worse very quickly and become unbearable. Mine were a little annoying but that's it. You were definitely right not to get the cheap Chinese "968" or "Turbo" ones.
Another thing to look at regarding poor running is the idle controller. It gets gummed up badly but kinda sucks to remove. I ended up spraying it out with carb cleaner, driving, spraying, driving, spraying and over the course of a couple thousand miles it cleared up. I also used Techron several times. The idle controller can affect other RPM ranges and throttle positions. Not WOT though.
Got the other side in, now just need to find my torque wrench
While I was rooting around, I noticed that the passenger's side mount looked possibly broken? The rear engine support bolt hole is more of a u, than a hole. It looks intentional, so did Porsche do it, or a PO, or is it a 'lucky' break from jiggling so much?
Here's what the old mounts look like:
Their party trick is you can pull the top completely off the bottom. Also, they were held to the car with nuts and bolts, which was extremely frustrating to remove. Gave my poor keyboard-posture-abused shoulders a workout
In reply to GCrites80s:
That's a good thought on the idle controller.
My passenger side mount wasn't so much collapsed as two wholely independent pieces
Torquing complete, car is back on the ground. I hope to fire it up and see how it goes, but I'm in the middle of packing to go see the eclipse. Might be tricky to pack and project car at the same time
that slot in the engine mount is how it's supposed to be, FWIW.
Did you do any belts on this car? If the balance shafts are out of alignment (which apparently is pretty common when people don't know what they're doing), it would cause some serious vibrations that could be mistaken for misfires I suppose.
It will probably feel WORSE with good motor mounts if that is the case.
In reply to irish44j:
I'm glad to hear that slot is supposed to be there. It did look intentional, but I don't have a lot of faith that every intentional looking thing on this car is as Porsche intended
I've checked the belts for alignment enough that I'm going to be really embarrassed if that's the problem.
