ferox

Bump for comments on an '81 carb before I put it on my car. I have heard qualitative comments that they aren't good, but nothing specific. I changed the accel. pump and needle/valve seat to later model versions. It's the simplest version of the Hitachi I have seen (choke and vacumm), and the jetting is different. Those are the four main differences I know. Here's the pics: (I know there is a spring missing I just didn't feel like redoing the pics)

It is in fact a California model. I have the original window sticker.

Good to know. I ripped, well, removed all that stuff as soon as I got the car. Now that I have an '81 FSM it's obvious that the '81 feedback system is a lot simpler that later versions. I was mostly concerned about MPG, so if the gains are minor I will just leave it the way it is. Thanks GD

I am rebuilding an '81 Hitachi carb to put on my '81 Hatch 1.8 4WD. I have been running an '83 carb for a couple years, and I like to rebuild about every two years. I have got an extra '83 that I have already rebuilt, but I would like to match the carb to the engine/ecu. Hitachi changed the design a bit after '81, and I was wondering if anyone knew the extent of those changes. The accelerator pump design wasn't that good in '81, so I am changing it to a later model acc. pump, but I want to know if anyone knows of any other reason not to use the '81 carb?

First off I am asking about the Duty Solenoid Valves (DSV's) on ea81's that modify the A/F ratio in the carb...not automatic transmission duty solenoids. I have had my DSV's disconnected (along with the other emissions stuff) for a couple years and have been running rich. The car drives great, but I would like to have the correct Air/Fuel mixture. I am rebuilding another Hitachi, and when I install I would like to re-install the DSV's and vacuum switches. Can I test the DSV's for actuation with a small 9V battery and miti-vac? I know I can test resistance and voltage in the car with the DMM, but I'm thinking actuation is the real functional test and I can carry a small battery and miti-vac in a junkyard. Does anyone know a good parts source for new DSV's? Aside from having more things that can fail, are there downsides to having the DSV's installed?

One important thing to keep in mind is that you probably have to check the gear oil level when it's hot, after you have driven around a bit. That's the way it is in ea81's, so I could be wrong since I don't ea82. If you flush it with gear oil let it drain for a little while, put the drain plug back on, and fill it to specifications. If you fill it right, it should read low on the dipstick before you have driven it, then check it when it's hot to see how close you are to hitting the mark. I use a quart of synthetic with conventional and it seems to work good. You might want to double check this, but if you fill it to spec. you shouldn't have any problems.

If I am not missing something my Haynes wiring diagram shows two things it could be: The obvious one is fuel pump control unit that Turbone suggested. Diagram shows a box with 6 wires. The inobvious is labeled as a seat belt timer. Diagram shows a box with 7 wires. With seven wires it must do something in addition to timing seat belts. It's near the glove box area. It doesn't seem likely though. I think I count 9 wires in your picture, so the diagram doesn't match perfectly in either case. The wire color coding looks a lot like some of the wires I spliced when I removed my external voltage regulator ('81 hatch), which I know your '82 doesn't have, but I would put my money on the fuel pump control unit. It ain't much, but it's all I got.

My Justy came with those wheels, obviously the lug pattern is different. It had some funny little center caps from another car. What's the diameter of the center hole on your wheels, I'll try to find the caps and figure out the make. Mine will be painted with semi-gloss black epoxy wheel paint this summer, but I paint all my wheels black. I just can't seem to get into chrome for some reason, but to each his/her own.

It doesn't make a huge difference on these cars, but if you are trying to eek out every bit of MPG you can install a fuel pressure regulator. The one on my '81 hatch is set at 2.5 psi. It's been on there so long I can't remember the performance difference. Since the pump on your car is in the back (mines under the hood), it will probably make less of a difference as far as smoothing fuel pulsations, which aren't huge in these cars to begin with. I think it's just generally recommended for carbed cars anyway, and it's an easy install. The cheapies aren't so cheap anymore, so I would go with a Redline or something that has a rheostat type dial vs. the set increments, so you can dial it in precisely.

I didn't see what vehicle this thread was started for, but the first thing I put on my '81 hatch were new empi brand axles. They sell reman's too, but you can get brand new ones too for a little more. I believe they are a German company and it might be one of those VW/Subie interchangeable things. They have been perfect now for almost three years. The CCR reman's might be just as good though.

FOUND IT! Factory crimp about 16 inches down the alternator wire from the original junction connection. FYI. I hooked it up. Got everything tidy. Turned the key and...it fired up like a new car. Voltmeter shot to 14.5 and didn't budge with headlights and wipers on. Headlights, wipers, and heater fan took it down to 14v Runs more solid than before with more power in higher rpms and up hills.

So I get my new GM 100 amper into my '81 Hatch, all the wiring done super nice, new #6 power wire from alt to battery, ext. voltage regulator removed, dash light bulb and circuit checked, 12 gauge field sensor wire from the alt to the junction, everything triple-checked, works great...so I put in the fully charged battery in, turn the key and ...nothing. No power to the ignition switch. I checked it with my meter...no power. I checked all the fuses...good. I checked my wiring diagram...AHA! It shows the ignition switch power wire (large white one) directly connected to the main power wire from the alt to the battery (clearly and unambiguously). I haven't seen this connection in any of the other write-ups, and I haven't seen this connection under the hood yet. I am about to go begin hunting it down starting at the battery/junction area, but I thought I would put this out there in case someone knows the exact location of this connection. I also entertained the idea that the ig. power is relayed off the original field sensor wire, but the wiring diagram does not show anything like that. Any thoughts?

I'm not sure how link a thread to a post yet, but to get to the discussion I mentioned in the previous post you do an advanced search for: alternator+wiring+question Titles only Sort by: Relevancy It's the first thread that comes up.

I took the pulley off the stock core alt I traded in just in case. The 100 amp GM alt. I got had a v-belt pulley. I ended up needing to add a spacer to get the pulley to line up with the crank pulley, so I tried the fitment of the old stock pulley and it was exactly the same.

Thanks GD. I'll make sure the sensor wire is at least as large as the pigtail at the stator plug. Thanks for the indicator lamp explaination too. I actually did a lot of reading on this before touching anything. There is a particularily helpful discussion you and RavenTK had with a certain Trikerbob I think, that had good explanations and good links. I read all of that, but it's great to hear it again, really. (ANYONE READING THIS THAT IS THINKING ABOUT THE SWAP WITHOUT FULL UNDERSTANDING OF THE SYSTEM SHOULD READ THE AFOREMENTIONED DISCUSSION...I will try to post the link in here later, I'm still learning how to use this site) I feel confident that I will not burn up my car with this upgrade now. Thanks again GD, helpful as always.

Thanks for the input. That gives me better info to talk to the shop with. I am going to get a second engine from the yard at some point so I can rebuild and swap as needed. It sounds like knurling could be a good option if the guides are only slightly worn. Luckily the head is actually accessible on the Justy without pulling the engine, so I can pull it pretty easily and swap if the thing starts smoking. Thanks again.

Thanks for the sensor wire tip. I was following the write-up by RenaissanceMan on the ext. vr removal and int. vr alt install, but that didn't include the j-box mod and a 100 amp alt. I was concerned about the fuel pump being affected, but he says it works after the VR extraction. So if I understand correctly the little white wire from the old ext. VR can be disconnected. I am just going to connect new the sensor wire (#12?) and the other white wire (currently in the 3rd j-box slot) to the original position spliced on the power wire before the j-box and it will be analogous to the original connection with a proper sensor connection and protected f. links instead of the old danglers. I am happy to say that I got the ridiculously large unit to fit where the stock alt. used to sit without fitment issues with the air cleaner. Looks good, we'll see how it works. Thanks again, I really appreciate it.

Alright, so thanks for your response and let me make sure I understand you in line item fashion. I'm just running stock electrical draw right now, but that will change in the future, and I figured if I hooked it up wrong I could end up causing an unforeseen draw that could be dangerous. The Nissan Alt. as it turns out would have probably been an easier install, but I was going by the GM alt. write-up which was easier than mine turned out to be. That, however, couldn't be accurately determined until I had ground down the ears and at that point I was committed. So we'll see how it goes. The fusible link box install was really just to clean things up and make sure I had a good junction. The fusible links dangling from the battery has always kind of bothered me. They could be augmented to not just hang there, but then why not just put them in a stock j-box. I will definitely get some EA82 boxes for future additions. Eventually I am going to do a bunch of relay by-passes and have accessories. The wiring diagram in the Haynes shows red fusible links. I don't have the FSM yet, but it sounds like Qman is going to help me out with that. My girlfriend's 84 wag has red, green, green. I wasn't sure if the white wire from the ext volt. reg. was the remote voltage sensor connection. It's a yellow wire entering the voltage regulator and a white one leaving it. If I didn't reconnect the three circuits from the volt. reg. wouldn't the open circuits cause some problems? Doesn't the remote voltage sensor connection go through the voltage regulator? Are you saying I should connect straight from the stator plug to the j-box? I am not trying to get fancy here, but I think my alt. and voltage regulator were on their way out, so it seemed like a good time to switch to a more powerful internally regulated set-up. I'm still not sure if you are saying that this set-up is dangerous, reckless, go, no-go. I've actually already installed everything, I just have to go get a different sized v-belt. My concerns are safety first and the integrity of the car. I really needed to do something about the charging system. I think I compromised my alt while welding a little exhaust hole (yes I used the ground clamp), I disconnected everything from the alt but didn't remove it from the car. Lesson learned, it has been weak and getting worse since then.

Today is a special day. I am doing the 100 amp GM alt swap on my '81 Hatch (which is requiring more fab than anticipated but that's another story). I am replacing all the wiring between alt and battery, removing the external voltage regulator and in-line fusible links, and installing a (post-'81) Fusible Link Box at the junction. It is this connection that I want confirmation on. It looks pretty straightforward. Pictured is the external voltage regulator and attendant schwag next to the J-box that is to be installed. Here's my plan: The black wire with the white stripe on the old set-up will go in the first position on the f. link box. The large white power wire from the alt. will be up-sized to 6 gauge and go in the middle position in the f. link box. At the bottom of the picture (on the old set-up) you can see three wires factory crimped and soldered to the large white power wire...two small white wires (one coming from the voltage regulator) and a blue one. I am planning on soldering those three wires to a piece of 8 gauge and installing it in the third position in the j-box. WILL THAT WORK? IS IT BAD? Thoughts or condemnations? Also, I am using 6 gauge wire between the j-box and battery. Seems like it will work, but since it's electrical and I am pumpin' more juice I would like a second (or many more) opinion(s). Sorry about the picture size, I cropped it and resized it and it still came out huge.

Thanks naru, good information. I tested it this morning and it's nice and steady. I'll test again after a drive.

I am just getting started on a rebuild of my '88 Justy. My internet research shows two strongly opinionated schools of thought on knurling valve guides. So I am looking for some input on that subject. Knurling vs. Reaming & Pressing new guides. I am not into half measures, so even though I am extremely poor right now, if knurling is cheaper but substantially inferior, then I would rather wait and do it right when I have saved up more $. If knurling is inferior, but not substantially so, then I might go that route and rebuild another head later with new guides. I searched for this subject and didn't find much, so I apologize if I missed a big thread on this.

I bought a new stock Hitachi ig. coil yesterday (Duralast brand). Started and idled fine, but I haven't driven with it. I tested it at the parts store 1.5 primary, 9.0k secondary. The primary was a little high, but they only had one in stock so I grabbed it. My car has been driving fine for the most part except the idle speed dropping low intermitently since I replaced the ND disty with the Hitachi. I replaced the wires connecting the pu coil to the ig. coil (reusing the original connectors) because I discovered several cracks in the insulation. No change. I thought I had it solved with the idle speed adjustments, but it's still doing it. I think it's my alternator actually. I've been planning the alt swap for a while among other things, but I think it moved to the top of the priority list. I would still like to hear what you find on your Hitachi. Thanks again.

So if I understand you correctly I need the pick-up coil connected to the ignition coil to test. I went out and pulled the female spade connectors in the disty up just enough so they were still connected and I could get my meter probes to touch the male spades. Five separate reading came back at 260 ohms, which still isn't spec if I'm doing it right and Haynes is right, but at least it's the right order of magnitude. I'll leave it at that for now, unless you have other suggestions. Thanks for the help GD.

If anyone is planning on doing the 100 amp alternator swap I have cross-referenced some vehicles they came in: 1980 Chevy K5 Blazer or Truck w/ a V8 1980 GMC Truck or Suburban w/ a V8. There were a couple V8 sizes but they both take the #7157 alt. They also came with a 63 amp part #7127, so make sure you get the 7157. When I called my local parts store with the part number they said they didn't have it, couldn't get it. I called back with the year/make/vehicle and they had three in stock.

That's the lowest I could go without overranging. I should have included that in the original post. I connected the positive lead to the spade and grounded the negative to the distrubutor housing and got 19.6 at the 20k setting, which is still high. Thanks for the help so far.