So I have a 1996 Subaru Sambar supercharged AWD and I recently replaced the distributor cap. The cap I used had the capped off vacuum line because everywhere I look the distributor cap on the supercharged version is not there as the ECU handles all the vacuum advance. Well my issue is that the distributor cap that was on the truck did have a vacuum advance that went to the body of the truck under the right side of the tail bed. My questions are; why would mine have/need the line, and is there any issues without having it? I will end up putting it back on tomorrow to test as I do have a ~20mph speed loss from what I assume is a vacuum issue, but I don't think it is from this vacuum link.
There is no vacuum line for the distributor on the SC model. There is a vent hose on the later models, but it does not connect to anything, just to atmosphere. Sounds like you ended up getting the earlier 1990-early 1996 cap which does not have the vent. There may be other differences between them as well, I have not put both caps side by side to see. You didnt say if you had a truck or a van, but if your VIN is higher than KS4-305201 (truck) or KV4-157001 (van), then you want the cap with a part number of 22162KA230.
I did switch out all the vacuum lines and still 20-30 mph under what I should be, but I do coast better at 40-45 now I guess
The connections to the hose on both sides are not plugged and are open. From what I read online the side that goes into the tail bed feeds to the front of the truck /shrug and the other side that feeds into the rotor cap is a vent cap or something like that. To be honest I tried a rotor cap that was plugged and it seemed to make no difference but I forgot to install the little spring in the inside center of it so it just melted the caps housing... I did find out that my supercharger seems to have no oil in it so I ordered some of that and hopefully that will resolve my loss of max speed issue (online says low supercharger oil may lead to a decrease in both engine power and fuel efficiency.). Fingers crossed.
Either way, the vent of a distributor cap would have no real impact on your overall speed. Low supercharger oil would not effect your performance either, it would just cause the supercharger to wear out faster. The oil only lubricates the gears that connect the two lobes of the supercharger together. They are still rigidly connected together via those gears, and the rotational force is permanently lubricated by the sealed bearings at either end of those lobes. Did you lose performance when you changed the cap? Or was this a loss of performance that did not improve when you changed the cap? What else did you change? Plugs? Wires? Did you remove the distributor body when you did the change?
I have never been able to get to 70-85 mph since buying the truck, but I've changed all vacuum lines, spark plugs, distributor cap, distributor rotor, oil filter, fuel filter, grounded the cat o2 sensor sense the ass end of the muffler never came with the vehicle, changed out all fuses in both behind the battery and under the drivers side dash, and changed the valve cover gasket. Next up on the chopping block is to add fluid to the supercharger sense it seems bone dry, change out the cam shaft and crank shaft seals (sense they are leaking), and lastly change out the timing belt, water pump, and thermal sensor (I have all the parts just need to do it). Oh and I would like to do a compression test after I get the seals changed just don't know how I would go about doing so. Is there an adapter I would have to buy to attach to an air compressor or is it something more complicated than that?
To be quite frank, you do not want to be pushing these trucks beyond 70mph if you want it to last at all. The engine needs to spin at 6500rpm in 5th gear to reach 70mph, and 84mph (140kmh) is quite literally at the redline of the engine. When you say you grounded the O2 sensor, do you mean the one underneath the distributor into the manifold? Or the sensor that does into the exhaust post-cat? Have you tried replacing the plug wires and/or adjusting the timing? Last question I have is if you checked the two rubber coupler hoses between the supercharger and the manifolds? Those get brittle and crack with age and if the outlet side is cracked, you will have a boost leak robbing you of power. They can be replaced with some trimmed down 48mm silicone couplers available on eBay/Amazon/etc.
From what I've seen online I should be able to comfortably hit 70 which I mostly just wanna cruise around 55-60 and can't. As for the sensor that I grounded, It is not the one directly off the manifold that is hidden behind it (that one is still there). It is the one that connects to the exhaust after the bendable pipe. Entire things missing so don't know exactly where on that metal brick but that thingy. I have not replaced the plug wires as that's something I will probably do next month when I get some cash and I have not adjusted the timing as I feel I should do that after I put on the new timing belt, but is defiantly something I will try. Funnily enough I did have to replace the 2 rubber coupler hoses between the supercharger and manifolds as they literally fell apart into many pieces. I used some radiator hose though because its what I had at the time so I might go back and do the 48 mm silicone couplers that you are suggesting. Who knows I might not have put the hoses on fully as it was a pain in the ass to try and squeeze it on (oil and pry bar baby).
55-60mph should be comfortable on a supercharged model. 65 is less comfortable, but should be quite reachable without too much fuss. 70+ is pushing it. The timing is done by rotating the distributor, which is why I had asked earlier if you had removed the distributor outright at any point. When you go to replace the wires, I suggest buying the NGK set from Amazon Japan. After shipping, it works out to be about $67 at the recent exchange rate. You can get them here: https://www.amazon.co.jp/-/en/gp/product/B0086T3BIK
Oh from my understanding though the distributor cap is threaded in with screws and only goes 1 way and the distributor rotor is also the same it goes in with a screw. Aka all I did was replace the cap and rotor (see pics). I thought the timing was done by using the timing mark on the alternator pully and using something on that side to change it. After looking at a video of a carbed version I do see where they rotated the distributor so I can try that tomorrow. Would you recommend getting the car hot and using a timing light on the timing marker or doing it on cold start? Or better yet would you happen to have a video of a supercharged version timing change using the distributor? Lastly, Thanks for the link on the NGK plug wires as everywhere else I've seen is like ~100 USD.
So, there are two bolts where the distributor connects to the head.. one on top, and one on the bottom. If you loosen those a bit, the whole distributor assembly will be able to rotate a few degrees. It should be more or less in the center of its range which will get you in the ballpark without using a proper timing light to dial it in. There are two green connectors under the dash behind the fusebox that in normal operation should not be connected to each other. In order to set the timing, you connect those together which will lock the ECU to 10 degrees BDC. Then you use the timing light on the crank pully and rotate the distributor until the mark on the pully aligns with the mark on the timing belt cover. Once that is done, you disconnect the green connectors under the dash to restore normal timing advance.
Ohhhh didn't know about connecting the 2 green connectors I'll give that a shot. I was able to use a timing light and make the performance a little better and I am now able to hit 50 and then slowly rise to 55 instead of getting up to 40 and struggling to hit 45. I'll try to do the connector thing tomorrow as I don't own the timing light and I would have to go there earlier than what now is. All-in-all changing the timing helped but still lacking top end power. I really feel it might be the cam and crank shaft seals as its just pissing oil and I pretty much have to top it up every 2ish days and I think its causing a huge vacuum leak. Still have to wait till next month to do that though and was quoted a laughable $800 for someone else to do the job even with me having all the parts to do the job.
So as an update. I changed the timing belt, camshaft and crankshaft seals, tensioner pulley, water pump, thermal sensor, valve cover gasket (again this time with extra RTV), added a new oil filter, and added new coolant and engine oil. In the process of doing so not only did I destroy my hands I also found out that the crankshaft pulley "12305KA410" was semi destroyed (supercharger lip was no more and the entire pulley was cracking). I suspect this could be and hopefully is the reason why I have a lower top end speed. My theory is that the belt isn't able to grab as much as it should and thus is losing boost. On the bright side after doing all that I can get to 60 mph and comfortably to 50-55. My question is do you think "12305KA550" is a compatible replacement as it is literally the only thing I can find without having to ship from japan? As for belts I believe "4PK650" will work for the alternator belt and "4PK735" will work for the supercharger.
The current part number for the 1995-1998 supercharged crank pulley is 12305KA550. Compatible supercharger belts: 4PK735, 4PK740, 290K4 Comptaible alternator belt (assuming no AC): 4PK650, 4PK655, 4PK660, 4PK668, 260K4 All of these are also on the Sambar Parts Spreadsheet that can be found in the References section at the top of the Sambar subforum here.
Sweet thanks for verifying. Start of next month I'll be ordering the crankshaft pulley and belts and I'll message back with hopefully some good news of moar power.
So I feel dumb, but I fixed my top speed issue and she RIPS now. Issue was caused by a hose clamp I had on the supercharger. essentially what it was doing was limiting the throttle movement so I couldn't push the pedal past a certain point (like I said rookie mistake). I still do need to change out the crankshaft pulley along with the supercharger belt and alternator belt before it explodes, and I would also like to change out the spark plug wires. On another note would you happen to know what the hose part number or what the id/od is for the radiator hose that goes from the temp sensor housing to wherever. Aka the hose that attaches to part 11060 in this picture?
Hah, yep, that'd do it for sure. Glad you found it. I replied to your other thread with the hose part numbers.
