7MGE Engine rebuild

[oregonjoe]

Before installing the Intake runner, you will need to route several lines through the runners BEFORE placing the intake on the head. Run the supply and return fuel lines, IAC Hose from the manifold, and water bypass hose through the runner.



The IAC Hose was tricky – it is an L shaped hose that connects to a nipple on the bottom of the Intake Manifold and runs up to the IAC. You can’t see the nipple once the manifold is installed so its much easier to locate and install it first.

[oregonjoe]

Once the Intake is in place you can place the main wire harness on top and run the connections for the Starter, VAC switches, Transmission Switch, Knock Sensor, and EGR temp down through the runners.



The connectors are color coded so it’s not too hard to match them up. You can reach under and attach the Knock sensor and VAC Can connection under the runners.

[oregonjoe]

A few more connectors



The knock sensor is under the intake manifold. The IAC hose connects to a nipple on the underside of the intake

[oregonjoe]

Next I installed the fuel rail and injectors. Soaked the injectors for several days in CARB Cleaner and cleaned off all of the connectors with Brake Cleaner.



Used all new O rings and grommets from the rebuild kit. The 90 Supra does not have a pulse damper on the fuel supply line. I spent an hour looking for one in the parts bag.

[oregonjoe]

Took a while to figure out where the two VAC line brackets went till I discovered they attached to the outside of the AIR Chamber bolts. One on the left and one on the right. The Blue VAC switch also attached to the AIR chamber. There were some grounding straps with 16 gauge striped wires that I was not sure where they went so I finally attached to the AIR Chamber as well. Not sure this is right since aluminum is not the best electrical conductor.



Mounted the AIR Chamber after installing the Vacuum controlled AIR VALVE. Before I installed the AIR Chamber, I installed the EGR Valve to the back of the head to get it lined up with the port on the AIR Chamber so they could be all bolted together at one time. Would have been very difficult to install the EGR after the AIR Chamber and get the gaskets on.



With the Air Chamber on, I could get the Cold Start Injector and IAC valve on next.



The IAC connects to the pre-installed hose from the underside of the Intake runner. One thing I found is that if you use RTV on the hose fittings, they slide on real easy with the spring clamps already in place so you don’t have get in there with pliers to finish connections. The RTV seems to set up pretty secure the next day. Hope it holds.

[oregonjoe]

I then secured the Valve Covers and put 4 OIL PLUG washers on the No 3 valve covers with lots of RTV as they were leaking before the project. Installed the new plugs with Anti-Seize as the old plugs were real difficult to remove. I then took all the old plug wires apart and rebuilt them with new wire and ends. Was able to custom fit each wire so the length were perfect. It takes 16 feet exactly of bulk wire to make up all the plugs. At $30 for wire and ends – saved $50 from buying a pre made set and got YELLOW as well

[oregonjoe]

Went to install the Alternator and discovered another problem – the lower alternator bracket must go on the block first – before the Air Compressor bracket and fan belt adjuster bracket.



This required taking apart the brackets on the timing cover. The Air compressor bracket wraps around the block and is very difficult to get too with every thing else installed. WORD OF ADVISE _ INSTALL LOWER ALTERNATOR BRACKET FIRST.

[oregonjoe]

I've been researching what type of oil to use for engine break in. Found this web site with some great explanation of what is going on and how to do it correctly

http://www.ntnoa.org/enginebreakin.htm

The bottom line is 30W NON DETERGENT

“The primary deterrent of break in is this heat. Allowing to much heat to build up at the ring to cylinder wall interface will cause the lubricating oil that is present to break down and glaze the cylinder wall surface. This glaze will prevent any further seating of the piston rings.”

"If the wrong type of oil is used initially, or the break-in is too easy, rings and cylinders could (read will) glaze and never seal properly. A fresh cylinder wall needs some medium to high engine loading to get the piston rings to seat properly for good compression but make sure you don't lug or overheat the engine. Use high quality, low viscosity oil (Valvoline 30 weight), no synthetics, too slippery. If synthetics are used during initial break in the rings are sure to glaze over.”

[oregonjoe]

Before I installed the throttle body, I pulled the spark plugs and connected the battery to give the engine a spin to see if I got any oil pressure.

Engine spun but pressure on the gauge. This drew concern since I wanted to be sure I had oil flowing in all the bearings before I started it up.

Checked the panel meter by grounding the lead and it pegged high so I know that was OK.

Then put a OHM meter on the Oil Sender and it read 5.7K which is not what I am used too from oil senders (usually read 30 to 240 Ohms). Kept the Ohm meter on the sender and spun the engine, it read 5.4K, still not right.

Then I read through the TFSM and it did not have any resistance specs for the Oil sender but said it would pulse at different rates to give pressure? HUM?

It did say idle was about 4 PSI and under load about 70 PSI so I would suspect starting would be a lot less then 4 PSI and not move the gauge at all?

Wish I had a mechanical gauge to check against – There is no real way to see if oil is moving around before fire-up?

[oregonjoe]

Well – spinning the engine for the oil test got me excited so I went on a marathon session and moved along in getting the throttle body, exhaust, belts, and radiator back on. The vacuum hose diagram made things pretty simple to connect up. Key thing I found was cleaning the inside of all the hoses with break cleaner made them “tacky” so they stuck better on the fittings. Used RTV on the water hoses expect for the big radiator hoses





Put the fuel pump fuse back in and connected the spark coil. Set the distributor to half way and shut the door.

Key in – turn, it starts.

OIL pressure gauge climbs up to normal pressure. Enough for the night.