When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
LTX and LSXPutting LT1s, LS1s, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects including repairs, swap info, and performance upgrades.
Here is a picture of the trinary switch. The installer didn't think it would fit, so he didn't include a high pressure switch. I'm going to try to install it on the evaporator. I assume that I have to depressurization the refrigerant?
The trinary switch threading Is the same as the stock low pressure switch. A little refrigerant leaked when I replaced the low pressure switch. The schrader valve prevented most refrigerant from escaping. Now I'm trying to confirm that high pressure can be measured from the drier. Then I need to review the 3 wires on the stock switch...
Anyone know if our cars have the accumulator type a/c system or the receiver-drier type? The receiver-drier type will work with trinary switch on the drier.
"There is sometimes a switch on the high pressure line, but that is to turn on the sec. fan when the A/C comes on."
--------------------------------------------------------------------------------
I have that switch on the high pressure line. Maybe I should replace that with the trinary switch.
Well that's just ****ing great! I loosened the high pressure switch, and R134 spewed out. Tightening the switch did nothing. The only thing that I accomplished is draining the A/C system.
I removed the pressure switch from the high pressure line. Looks like the installer used a 4th gen high pressure switch there, and E38 has a connection for it. The trinary switch thread size is too big for that connection. So, I'm going to have to re-install the 4th gen switch for the E38. I'll have to figure out another way to install the trinary switch on the high pressure line. I also need to lay low for a while. Ozone levels are dropping over North Texas.
I'm looking into having a custom A/C line made that will have two service ports. One for the gen iv high pressure switch and one for the vintage air trinary switch. The E38 has an input for the 3 wire A/C high pressure switch. I don't know why it needs that input since a 58x ECM hasn't been programmed to control the A/C.
I got an 82-88 Firebird A/C line with 2 ports from eBay. Now I'm waiting on an R12 to R134a adapter. The ports are size -3 AN (3/16 inch), and the trinary switch is -4 AN (1/4 inch). I think the adapter will allow me to connect the trinary switch to one of the ports. If not, I can add a -4 AN port with another product from Vintage Air. This illustrates what I'm trying to do... I want to go with option B, but option A will work if I can't connect the trinary switch to a port on the A/C line.
You can have a line made without the need for adapters. Go to a hydraulic shop that services industrial customers. My local Caterpillar dealer also has a hydraulic shop that could easily do this.
I tried to do that once with a hydraulic brake line. I found a shop that sold lines and had a flaring tool. I don't remember who the primary customers were for that shop, but the guy wouldn't help me with my project due to liability concerns. I eventually found a shop online that had what I wanted.
The Ebay Store that sold me the A/C line can make a custom line. I may go that route if the port adapter doesn't work. The schrader valve complicates things.
Working on a car during a Texas summer is slow going. Even with a fan blowing in my garage, I can only work on the car for 30 to 40 minutes. Then I enter the house drenched with sweat, and I spend another 30 minutes cooling off and cleaning up. It had to be done as my brakes were mushy and my A/C was missing a high pressure switch.
Two weeks ago - I was under the dash, removing the bolts of the brake booster. It sucked
Last week - I was installing the new brake booster, bolting it down, and bleeding the brake master cylinder.
Sunday - attempted to bleed brake lines with motive power bleeder. No joy. A stream of brake fluid streamed out of the MC after a few pumps.
Monday - raise car on jack stands. Remove wheels. Where is that stupid locking lug nut key??
Tuesday - Remove locking lug nuts with hammer and heavy steel socket. Bleed brakes with gravity method. Put wheels back on. Lower car. Notice that vacuum hose doesn't fit check valve on brake booster. Curse brake system. Walk into house. Open ice cold beer. Begin clean-up procedure.
I'll share one of my tricks. A wheel key can be hard to find or lost. I kid you not, I keep mine in a large nut jar from Costco. You can always find a big jar in the garage.
That's a good idea. I bought another locking lug nut set, and this time I'm determined to not lose the key.
Yesterday, I added R134a to my A/C system. The vintage air trinary switch is in position. Just as I was disconnecting the bottle of refrigerant, the engine died. I started the car again, and I checked out the A/C system while the car idled. Then the engine died again. This time, I couldn't restart it. Was it flooded? Vapor lock? Surely not with a gen iv engine. I think I've narrowed the problem down to fuel. I sprayed some starting fluid in the throttle body. The engine caught for a moment and then died. I've got spark. I checked the wiring to the fuel pump relay, and it looks fine. The fuel pump must be kaput. I added 5 gallons of fuel earlier in the day, so I know the fuel tank isn't dry.
I had a fuel pump access panel installed, so I didn't have to drop the tank to get to the fuel pump. I removed the fuel pump housing assembly. While I had it out, I replaced the fuel level sending unit with the grand prix model. My fuel gauge works properly now. I tapped the fuel pump a little while I had the assembly out of the tank. Once I replaced it, the engine still wouldn't start. I suppose I should check the fuel pump wire to see if there is a 12v signal. I'll of course be mindful of safety since I'm working close to 10 gallons of exposed gasoline. If there is a 12v signal, then the pump is most likely the problem.
Any recommendations on how I should proceed and on which fuel pump I should buy?
ok - I ordered an EP381 AC Delhi fuel pump. It's much cheaper to buy the fuel pump rather than the entire fuel pump housing assembly. Amazon had the best price for pump+ 2 day shipping. Also, I've installed the trinary switch. The lower connection to the A/C condenser was the only location that would fit the Vintage Air port fitting. I'll run the A/C clutch wiring through the trinary switch soon.
It was a dark and stormy night...I was driving home around 1am last night / this morning. I just finished a total beatdown of a shift at my airline job as heavy thunderstorms covered north Texas. The windshield wipers barely kept up with the downpour. I came to a stop light and had a thought... 'Oh s*** !!! My Trans Am is parked in front of the garage. Immobile due to an inop fuel pump. And the windows are rolled down!'
When I got home, I quickly walked over to the Trans Am. I thought water would poor out of the car when I opened the door. Fortunately, it wasn't near that bad. I rolled the windows up, and it was a slow progress. Thank goodness the window motors still work. Like the fuel pump, those motors don't have much life left in them. I'll be smelling mold in the car for a while. The interior is already slated for an upgrade this Fall. No harm done, I think.
I replaced the fuel pump and tried to start the car. No bueno. The new fuel pump wasn't a direct fit. It will still work, but I went cheap and got a mediocre result. I'm going to order a replacement fuel pump housing assembly, and then I'm going to have the Trans Am towed to Garland again. This could be a VATS issue, and I could spend a week sending the ECM to Speartech for testing. But then again, it could be the fuel filter/regulator, the fuel pump relay, a wiring harness problem, etc. I've checked every connection that I can see, and it looks fine. The fuses are fine. The ECM is grounded. I'm not getting a fault code from the OBD2. I don't have enough free time to keep troubleshooting this, and I need a break from the car. Last night, I walked into the house around 11pm. I was soaked with sweat, and I reeked of gasoline. The wife was not pleased.
This is why I installed a red neck fuel pump access panel. I know it's a controversial issue on this site. I'm just glad that I didn't have to drop the fuel tank to inspect the fuel pump.
I got the car back. I should have looked more closely at the fuel pump wiring and connections. That was the problem, and it was a simple fix. Oh well. The car runs again.
i drove it to Discount Tire and bought some new shoes. They asked me to pull the car into their bay. I guess they didn't want to be responsible for damaging the headers. The long tubes do go a bit low. When I started up the car, the deep lopey idle elicited some grins in the shop. I'm pleased with the cam I chose.
The car rides smoother now, but I still need an alignment. New front springs were part of the LS swap. I'll probably get that done next week.
I installed the trinary switch next to the radiator. It was the only location the had the same thread size as the vintage air trinary switch fitting. I also replaced the dryer and the orifice. Then I vacuumed the system. Yesterday, I added R134A. The A/C works! The trinary switch is doing it's job as the A/C compressor was cycling on and off even when I jumped the low pressure switch on the dryer.
It was a little cooler in North Texas today. Temperature is in the low 80’s, but it’s very humid. It feels like an armpit outside. I bought another small can of R134a, and I finished charging the A/C. Condensation began to bead up on the dryer, and the A/C is blowing cold.
I drove the car around a bit today. The A/C worked well, but heat started rising from below once the headers got hot. I'll enjoy driving this more in the winter. My first stop was at an oil shop to get an inspection. Everything worked but the horn. So, I told them I'd be back once I fixed it.
I went to the gas station and filled up. Checking the fuses, I quickly found the problem. The horn and interior lights were operating again, so I went back to the oil shop and completed the inspection process. Peace of cake in Texas. I've got the wrong oil filter on the car, and it leaks a bit. I was hoping that I could just get a quick oil change and be done. The headers won't clear the metal boundary around the oil changing pit. An unexpected annoyance from the long tubes.
I never did mind the little things. But it sure does feel good to fix a little thing! I bought new struts for the rear hatch. Again, info on this board was very valuable. I didn’t buy the struts that are too strong. I read about the rear hatches that would violently open when unlatched! My rear hatch operates as it should now. Cool
The oil isn’t leaking from the filter. It’s leaking from the oil pressure sensor. I read about an autometer adapter, but I think I bought the wrong one. The male threads look too big for the oil sensor port. We are getting aggravated. Yes, we are.
I think I got the oil leak stopped. Time will tell. The fuel pressure is still too high, though. I researched ls1tech, and i decided to change the fuel filter. Like most, I’m using the 99-04 corvette fuel filter / regulator. My attempt to replace the filter did not go well, though. Gas went everywhere, and my garage is now a disaster area. I’m talking Exxon Valdez here. While the siphon effect kept gas flowing from my tank, I discovered that I need a disconnect tool to detach the fuel filter from the forward line. I finally got the leak secured, but the Trans Am is out of service, awaiting parts. I took a shower, and I still smell like gas. My old clothes are in the washing machine, and my shoes are airing outside.
Irony can be pretty ironic sometimes. So I failed to yield the right of way on a left turn back in 1988. I caused a wreck which ruptured the gas tank of a modified VW Baja Bug. Gas poured onto a shattered fog light, it ignited, and my dad’s 1984 Z28 burned to the ground (along with the VW bug).
Fast forward 29 years. I attempt to replace a fuel filter on a modified 1984 Trans Am. Due to poor planning, 10 gallons of gasoline drain from the tank before I found a way to secure the fuel line. Every bucket in the shop is full of 93 octane unleaded. The gas eventually evaporated from the garage floor, but I still get a wif of gas from my hands. Maybe it’s the shoes. Bottom line- I don’t like this. Thank goodness a VW bug wasn’t nearby while I was working on the car!
The replacement parts arrived today. Tomorrow, I’m going to finish the repair. No smoking, please.
I got the new fuel filter installed. When I tried to start the car, the engine didn’t fire up. I looked at a photo that I took before I removed the old fuel filter. Yep, I got the fuel lines crossed. So, I had the wonderful opportunity to get under the car again and work with gasoline. 10 minutes later, the lines were properly connected. This time, the engine fired up. Unfortunately, the fuel pressure is still too high. Maybe it’s gauge error? Maybe the spigot needs to be pulled out more.
95psi or so? Either your return line is blocked or you have a gauge error. If it idles semi-decent, Id point to the latter. Either move the gauge to a known good fuel system and retest or put a different gauge on the system you have now
Playing with numbers a bit; if it actually was that high of pressure, your 42lb inj would act like 54lb inj causing a severe rich environment. It should be blatantly obvious with black smoke or a heavy gas smell coming out of the exh. Thats all assuming your pump can even hit 95psi. More evidence to look into the gauge
I got an alignment for the Trans Am this morning. I went to a shop with mechanics instead of technicians. The guy told me that the idler arm was bad. The front wheels had too much play. That surprised me a bit as I replaced most suspension components a few years ago. I haven't driven the car more than 100 miles since that time. So, I did some searching on thirdgen, and I found this: https://www.thirdgen.org/forums/susp...dler-arms.html
I used moog parts, so that explains the problem. I told the mechanic that I'd deal with it later, and I headed home. I took the car up to 70 mph. Hmmm...I felt a vibration in the frame. It wasn't coming from the steering. It was coming from below. A little trouble shooting, and noticed some clunking when I released the clutch at slow speed. With great care, I got the car back to the shop. Sure enough, the rear U-joint on the drive shaft was bad. I'm busy, and I get nervous when I work under the car. I left the car at the shop, and I'll let them fix the idler arm and U-joint. I'm using A/C delco this time for the idler.
I got the car back today. I had to order the idler arm from Rockauto as the shop couldn’t find an A/C Delco locally. It took 2 days for the part to ship, and that thread was spot on. The car drives nice and straight. The driveshaft U joint fixed the vibration too. Before, I thought I needed a new rear view mirror, because it vibrated at highway speed. The vibration is gone. For the first time since I bought the car, it feels stable at highway speed.
I still need to address some issues. In 2012, I replaced lots of steering components per a thread with instructions. The panhard bar is loose or something. When I took a left turn, the rear end yawed to the right. My feet were off the rudder pedals, so I don’t know what happened. Just joking! Maybe it’s time to look at subframe connectors.
I’m watching Fast N Loud now. Others have told me that I need to watch the show, but I didn’t get around to it until last week. Cool show. I think I’m going to visit Sue’s shop soon. My interior is nasty. The Recaros...I don’t want to even think about it.
30 years today! I figured this April 22 would be a good stopping point for my build thread. The LS swap is finished, and I’m now focusing on the interior. This forum is a great resource. When I first bought the Trans Am, I was just going to replace the 305 with a 350. One thing led to another, and well..I went the LS route. I’m glad I did. It was certainly worth it!
06-15-2017, 06:46 PM
