BritishV8 Forum

Can't wait to hear the next part of the story.

Dennis

Well the hornets didn't take the hint so it appears sterner measures are needed. Regrettable, but I was here first. It's my shop, my property, my forklift, and they are denying me the full use of my possessions. They will have to be evicted and there are only so many methods available to me to accomplish that. Could be that tonight they will get another visit, weather permitting. I'm not very hopeful at this point that they will leave peaceably and since war it will inevitably be, it will be war on my terms. I have the technology to eliminate most of the risk of casualty on my side of the battle and am unwilling to give up that advantage so they basically have until midnight. It's just too bad that I have no means of effectively communicating that deadline to them.

Meanwhile, Here is a shot of my mass airflow sensor as installed in the riser.



The two rivnuts may disturb the airflow slightly but it was either that or more TIG welding, machining and polishing as one of the tapped holes had insufficient threads. Below is a rear view of the sensor. I'll have to look back and see what the application was, I think either Buick or Cadillac. I'll need that for the calibration data.



Next shot, I have the coil packs mounted, one set to the heater box cover, these will feed the even numbered plugs, plug wire kit is on the way. Those have become available since hot rodders started placing their LS coils on the firewall or inner fenderwell. They  have 5 ft long wires but I'll need a spark plug wire crimper and I'm pretty sure I don't have one other than a home made block and punch set. That would work but it tedious.



Lastly the FPR is installed and the lines connected. The other set of coils are visible in the lower right corner. Still need to finish up the heater valve and one small vent line and then I believe the plumbing is done.



So the scoop can go back on, then throttle linkages and wiring is left, plus fluids, programming and some small hardware concerns, charging the AC, and a few other details. This has actually turned out to be quite a massive upgrade in a lot of ways and I'm pretty pleased to be near the end of it.

Jim

Yesterday I finished up the rest of the plumbing and got the scoop bolted back on, as well as stripping the friction tape off of the coil pack sub-harnesses. Good news on the wiring is that I was able to pull just enough slack to make all of the connections except the front coil pack so the rewire will just consist of that, the MAF sensor, the bonnet struts and replacement of the inertia switch and pigtail. A couple day's work probably. Then there is the throttle connections which will be a bit of a puzzle. I'll need to get the car back on the lift for fluids and final inspection as well.

I'm thinking it should start and run pretty well on the last tune I had for the 340, so that is most likely going to be my starting point. We shall see.

Jim

Jim, get rid of those hornets. About twenty years ago during the winter my late mother got another blanket out of the airing cupboard to keep warm at night. Unknown to her there was a hornet hibernating in the folded blanket, during the night the hornet crawled into her mouth and stung her tongue. Fortunately she had a Piper System and unusually for her was wearing the emergency call button on a neck strap, although she couldn't speak due to her swollen tongue the operator had an ambulance sent to her house. By the time they got to her she could barely breath let alone get out of bed, another plus of the Piper System is that they are able to tell the emergency services the code to get the spare key. I wouldn't give them an hour of survival let alone a day.

They are gone and so is their nest. Oddly enough they seem to have just disappeared in the night with hardly a trace, although I may have happened to see one  oddball buzzing about. Anyway that's my story and I'm sticking to it. Maybe they were transported away by aliens, I simply couldn't say. So for the last couple of days I've quite enjoyed opening the end door to let the breeze blow through, happy and secure in knowing that there will be no vengeful bees seeking me out to do harm. I have in the past been stung by hornets and have no wish to repeat the experience.

So anyway I've replaced the inertia switch and pigtail and made a pair of foam speaker backs and plan on rewiring one of the coil pack sub-harnesses next and that should let me finish up the wiring except for the bonnet struts and the MAF sensor. I spent most of the day getting the tail lights and trailer connectors for the Samurai sorted. Still waiting on brake hoses there so it has the lift tied up but once that's done I can check fluids and finish up this job.

Jim

Curious isn't it, how when you look you find things needing attention?

Just minor stuff like the spark plug wires for instance.... there weren't any. Couldn't be anything I've done however, the car simply didn't come equipped with the proper ones.

Then there's the alternator wires, I'm not fully confident it'll work without them. The brown/yellow one to the bulb I found but the one to the battery? Nah, no evidence of that. I suspect it might have vanished when the remote sender for the ammeter went in. That would have coincided with the iron head 300 and it's 1 wire alternator so it would have been not-essential at that time but surely I'd have recognized I'd need it later? I seriously hate just adding redundant wires. Don't strictly have to have the sense wire, and it doesn't strictly have to come directly from the battery but you give up a couple tenths of a volt charging if it doesn't so I like to use it with such a remote battery. The wire for the AC compressor is there I'm quite sure, if I could just find it. Nothing matches as it should on the MAF wiring so that'll be fun. The Google AI has been surprisingly helpful on that so far and some progress has been made but the pin assignments on the ECM don't quite line up yet. Probably need to give 'em the service number off the ecm.

But amazon and ebay tell me they will deliver today and it's a sure thing.... Sure! Is that what they mean? I *really* want my Samurai golf cart back.

Ah well, too hot to get excited about anything today so I'm sorting through small coils of surplus wires to get matching colors. Guess I've been slacking off a little in my documentation, where does that grey/red wire for the AC clutch go after the on-off switch and the evaporator thermostat before it changes to gray and shows up under the hood? Buried behind the dash of course and there are a few other gray wires unaccounted for there. "Oh Sure, no worries, I'm bound to recognize what's going on here", anybody would right?

So it's my noon break complete with half a pepsi and half a Hershey bar to help maintain my girlish figure. Ain't life GRAND!?!! Not a cloud on the horizon. I'm feelin' GOOD! We got spotify tunes on the hearing aids and the world is fine.

Jim

Details, details, details and so it goes but at least the end is in sight. I finished up the coils and plug wires which required re-splicing the sub harnesses and re-wrapping them. Fortunately I had a roll of vinyl flat wrap and some silicon rubber tape on hand as that makes a fairly neat and compact bundle. Must be why it was popular. Below is the left side set of coils with the plug wires tucked neatly under the headers.



I bought a quality set  of ratcheting crimpers to do the spark plug wire ends and it did a good job so I recommend that method.



The second set I put behind the intake, just enough room to mount them on the heater box.



I plan to run a ground wire from each coil bracket to the head for a short and direct return path for the spark. That's noisy enough without routing it all about the car.

So what's up for today? Hard to say really. More wiring I suppose. Google's AI was more than a little helpful in sorting out the wiring for the new MAF sensor and IAT so probably that next. Also should look through the spares to see if I can find a connector body to replace the one on the CLT sensor as I managed to break the latch on that one somehow. Then of course there's the alt and AC clutch to sort out but the list is decreasing.

I have this neat illuminated blue pushbutton switch that I ran across decades ago and bought for a future AC install. It is sorta unique in that it mounts from the back of the panel with a decorative nut so the switch body can be a lot larger than the hole with plenty of room to hook up the wires. Very nice, but over time the button aged out and split down the middle. I ordered a couple of possible alternatives but then thought maybe I could fix it. I discovered it's made to allow the button to be pulled out to swap colors which was another cool feature if I only had replacement buttons which I don't and likely can't get. The alternative would be to fix the button, I mean after all the switch itself is unused. NOS. So I glued the two halves back together and ordered an assortment of thinwall brass tubes. They are metric but the 9mm is a good match for the button's OD so the trick is going to be getting the button into the lathe without breaking it and turning about half the length down about .040" so a collar of brass can be glued over the outside. I think I can make this work. Making a new button is another alternative and I could surely get some round polycarbonate I expect but turning it blue might be a trick. I'm not sure a blue sharpie would be a lasting solution.

OH! I know! Maybe I could get Jim Miller to print up a new button and put a snowflake on the end of it! Wouldn't that be just too cool? It could even be a mushroom button.

Jim

The mushroom button gave me ideas so I ordered some blue acrylic rod and will do a little lathe work. The mushroom should make that end stronger and hopefully prevent cracking. So I reinstalled the switch.

That sensor you see in the photo above is the IAT sensor and there is one built into the 5 wire MAF sensor so it's now surplus to requirements and I've removed it and ordered a stainless plug to replace it. I found one with the right thread depth and a seal under the hex head so some light buffing should be all that needs, possibly a facing cut if the depth does not match exactly. That'll give me as smooth of a transition there as I can get. Ideally I would not have that 90 degree bend right before the MAF but, well space constraints and all that. The throat has roughly twice the area of the MAF in the '02 Camaro which is the base for my tune so I'll have to scale the table accordingly.

The IAT leads are now hooked up to the 5 wire MAF and I'll have to run another shielded cable for the 3 MAF leads. These teflon insulated shielded cables are working out well. They are quite small but have good sized conductors. Termination is not difficult at all and they are fully shielded with a stainless braid. The teflon jacket has not frayed as far as I have seen. I'm grounding the ECM end of that, the sensor end shield gets pulled back and then slid over the ends of the butt splices before heat shrink seals it all off, using the 22-26ga splices. I've finally gotten around to ordering a ratcheting crimper that can handle this small size, they are still not mainstream and won't be found at the box store. I've been doing them with a pair of antique dental pliers.

I ran a sense wire back to the battery, routed it in the corner under the carpet where I have the rest of the fore/aft wiring routed. It's a well protected location and easy to access. I have been trying to decide whether it should connect on the car side or the battery side of the ammeter shunt, but since it's job is to detect actual battery voltage and because the shunt represents at least some level of resistance in order to be able to sense the bypass current for the meter I think the battery side is probably the best. The alternator should never draw enough current on that wire to show up anyway. I suspect a heavy draw there would show up as poor charging anyway. So I have that and the alt wire at the fuse location and ready to go down to the frame rail and forwards but I'm waiting to join the AC clutch wire to it, along with a ground. The bonnet wires can also go in that sleeve at least most of the way. I *think* the gy/r wire from the thermostat probably goes to the ECM and then that turns on the clutch but I need to confirm it. The ECM may ground the clutch and it may need a relay so that might not be quite as simple as pre-ecm wiring. That just occurred to me last night and sounds like how I might have wired it. That leaves the MAF cable as the most challenging bit as it has to go through the firewall and also have pins inserted into the ECM connector. I'll be looking for terminated wires of the correct colors in the surplus wire bin. The ones for the AC should already be connected and I should have the ones for the MAF so that should go smoothly once that's done although I have 'stuff' above the firewall pass through and may have to use an alternate and longer route but I hope not, as my last remaining bit of 3 wire shielded is not as long as I might like and I'm not keen on ordering more right now.

And, that still leaves the bonnet actuator wiring. Overall it's not much is it? I get that last bit done and I can move on to loading the 340 tune back into the ecm and comparing that to the current 300 tune. Along with loading a new MAF table, enabling that, and enabling the AC controls. By then I'm quite sure I can have the car back on the lift to add fluids and do a final check.

Jim 

Jim,

Do you have this wiring diagram? Do you have a compatible pressure transducer in the system? My assumption is everything needs to be in place, at least this is how I'm wiring mine.



Scott

Basically similar. I don't have the pressure sensor But I'm pretty sure I can turn that off in the software. I've traced out the circuit in the car except for one device that I haven't located yet. It's in the control circuit between the thermostat and the relay and appears to be in the engine compartment. At the moment I'm at a loss to identify it, I guess that's what I get for getting creative. I'll just have to trace out the wires tomorrow to find it. At the moment I just can't think what it might be.

Jim

Quote from: BlownMGB-V8 on July 20, 2026, 07:05:33 PMBasically similar. I don't have the pressure sensor But I'm pretty sure I can turn that off in the software. I've traced out the circuit in the car except for one device that I haven't located yet. It's in the control circuit between the thermostat and the relay and appears to be in the engine compartment. At the moment I'm at a loss to identify it, I guess that's what I get for getting creative. I'll just have to trace out the wires tomorrow to find it. At the moment I just can't think what it might be.

Jim

Jim, maybe you can play with the pressure values in the configuration in some way? The compressor relay won't be energized unless the pressure is at a specified value. As you know, that's how it is cycled. How are you cycling the compressor without a pressure sensor? 

I'm about two weeks away from being ready to charge the system. I got the compressor/belt/ tensioner installed this afternoon. It's nice to see it spinning at last. 

Scott

I know, right? It's the hardest part of the job, almost at the end but getting those last few bits that have been put off because they are the least enjoyable ones. I guess you'll be charging with r134a? Can't wait to find out how well it works. Almost like we are in a race to the finish! My goal is to have it done and dusted in time for my birthday bash at the Cincy meet. Really looking forward to that this year, especially after the last two went a little sideways. Angel Breath just in time for the hot days, right?

I went old school on the compressor control. A pushbutton on/off switch and an evaporator thermostat with a dashboard knob. Those two wires I thought went forward? Yeah, they go to the ECM, don't know how I missed that. In the bundle they must go down instead of up, very hard to see back there under the shelf. Must have just been tired I guess. I kept trying to think of anything else that might be used in that control line and there was just nothing. Plus, I had already located the relay by shorting one of the ecm connector pins. That would have had to have been the gray one going to the relay control. I will have to double check the gray/red one for signal {12v) on the demand pin. That's the last mystery solved I think. So all I should need in the tune is a way to force the compressor on in the ecm any time it gets a demand signal. I should be able to hear the relay click when it turns on. I need to fish a heavier wire from the relay to the compressor, so that's on for today. Then those wires go in a sleeve to run forward along the frame rail and I can finish it all up. Maybe get done today, maybe tomorrow but I'm shooting for today.

The inside end of the maf cable is done, that was tricky. The sense wire (yellow) carries a frequency signal in the 2khz+ range and the two others supply + and - and originally none of that is shielded. I wanted to shield the signal to remove a possible variable since I expect some trouble from the duct configuration anyway. Normally I'd use a shielded 3 conductor cable there and ground the ecm end of the shield but instead I'm using 2 conductor and will supply the ground with a short wire from the body ground at the power block on the inner wing. I'm leaning towards the body ground as that appears to be the way it was done to start with and could help isolate that ground from the signals. With the sensor generating a frequency it's possible for an image of that frequency to be carried back on the ground, so it's probably better to ground that at the body. Very technical stuff, but it needs to be considered.

Man the body on this car is badly in need of a wash. Probably a good sign that I'm thinking about that.

Jim

Quote from: BlownMGB-V8 on July 21, 2026, 10:14:31 AMI know, right? It's the hardest part of the job, almost at the end but getting those last few bits that have been put off because they are the least enjoyable ones. I guess you'll be charging with r134a? Can't wait to find out how well it works. Almost like we are in a race to the finish! My goal is to have it done and dusted in time for my birthday bash at the Cincy meet. Really looking forward to that this year, especially after the last two went a little sideways. Angel Breath just in time for the hot days, right?

Jim, I'm in no real race to get it done. I'll be driving up to Sandusky on August 25th so I'd like to have it working by then. I'm sure there will be some sorting things out, there always is with a big project. Yes, I'm going with r134a. We will see if it works like I hope it does!

Gotta be about the slowest race on record if it is. I was hoping to finish the wiring today but a new honeydo popped up so maybe not. Spent some time yesterday on wire routing and sleeving, down to the last 4 connectors. STILL waiting on my brake hoses for the sammy. Memphis FedEx SUCKS!

Jim

I had really hoped to complete the wiring yesterday but at least I got close. A blown fuse had me locking up just before I finished. That's OK, I'll do it today.

I just realized, that teflon insulated cable I've been using for sensors reminds me strongly of the sensor wires they use in jet aircraft engines, I wonder why I didn't recognize it earlier? Probably just left over ends somebody is selling on ebay.

So if all goes well today, I can put the console and radio back in, check off the wiring and go on to fluids.

Jim

I'm putting off the console until I decide if I want to do anything with the sound system but I may wait until winter. The rest is done other than the throttle cable and programming.



Guess I'll make a cover for that hole also. Nuts and bolts for the strut pivots as well. As all of us who do these things are painfully aware, at the end there are always unexpected items that pop up and often cascade into bigger jobs. Such was tidying up the wiring bundle under the hood and putting things in order generally. That blown fuse? Turned out to be caused by a fat diode I put across the relay terminals for the AC clutch. It didn't like 12v and decided to conduct both ways. Since it was one of the last 2 wiring changes I made that wasn't too hard to find. Replaced it with another surplus unknown fat diode and all is well.

I ended up having to modify a support bracket for the relay panel as it was hitting the re-routed plumbing for the surge tank drain. Tedious but not difficult. And so today I think I will be able to add oil and perhaps even coolant.

I do need to go back and research this thread to see if I made any mention of actually putting oil in the compressor. I'm pretty sure I did but I really wish I'd made note of it with a sharpie to remove any doubt. I dislike the uncertainty.

So that's it for now. It was surprisingly difficult to find bulk throttle cable in the right size but it's likely I just never went about it right. I ended up calling Speedway and ordering a 48" cable from them and hopefully it'll be the right stuff.

Here is another example of unobtainium:





This little bugger seems to no longer be in production. It's a shame too, it's a lot nicer than the alternatives. Lights up when blown, has a clear epoxy top with a nice organic rounded shape. They do become dull with age but still look better than the squared off ones.

Jim

Yesterday I flattened the sides of the glove box liner by heating them and clamping between two pieces of plywood until they cooled, that worked well enough. A bit of spot putty in the seams and it'll get some paint before going back in.

I also added the break-in oil, anyone care to offer break in advice for a roller cam engine? I added the antifreeze but that didn't turn out so well. I seem to have a leak in the radiator but with the sammy still on the lift couldn't sort out exactly where it is.

Then I made a new button for my AC compressor switch. Here is what the original button looked like. It's glued back together after it had split down the middle into two halves.



And here are the two buttons after I had made the new one out of some blue acrylic round stock.



I thought it turned out rather well, I used an old school method to make it shiny referred to as flame polishing that works well with acrylic if done properly. Here the part was spinning in the lathe which turned out to be critical as the heat partially melted the part and it would have sagged otherwise. It was heated until shiny and than left spinning until cool.



Last shot shows the illumination. It's an old switch so it uses an incandescent bulb rather than an LED. I could swap that out but it ain't broke so... The acrylic will carry the light out to the edges of the button, making it just visible from the driver's position without being too bright.

Jim

Quote from: BlownMGB-V8 on July 25, 2026, 06:54:40 AMI also added the break-in oil, anyone care to offer break in advice for a roller cam engine?

Jim, I used Valvoline VR1 10W-30, which is high zinc, on my new GM 3.4L V6 with roller cam.  It wasn't a smooth path to get the first 20 minutes at 2500 RPM but everything seems to have turned out alright.  It's also available in 20W-50.  I'm onlY one data point but FWIW.

John

Since this is a new engine break-in, I would certainly use a good break-in oil.  With the roller cam it does not need to be high in ZDDP.  My understanding is that a roller cam does not require any break-in.