Matt's cylinder head rebuild - Finished

[suprarx7nut]

Your second problem is related to what we call "hot start". The engine starting procedure is slightly different when it's already warm. Lots of 7M engines have a hard time starting warm in my experience. I improved my last 7M by replacing the Fuel pressure up VSV. Mine did not appear to be working according the TSRM specs and replacing it seemed to help hot starts.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=116

 

[slowerisfaster]

Thanks. Of course it would have been so much easier to get to with everything taken off, but that's how it goes. I will test it when I get the chance (may be awhile) and report back.

 

[slowerisfaster]

Don't forget the valve clearances. Toyota uses shims in buckets, there are no adjusting these except by putting a different shim thickness in. They can be a pita to mess with so make sure the machine shop has experience on this. If you do it yourself you will need a micrometer and a tool to remove the shims. And try not to mix them up.

Good advice is only good if you USE it. Lesson learned.

I guess I thought the machine shop was going to check the valve clearances, but since they thought the camshafts were junk and did not re-install them, I guess they never got around to it. I should have realized this and checked the clearances myself before putting the head back on, but that's what happens when you are anxious to get your car back on the road.

I have no idea if incorrect valve clearances would cause the idle problem I have or not, but I figured it couldn't hurt to check them anyway. I've got it back apart and sure enough 12 of the valves were out of spec. I was able to move a couple of them around, but ended up ordering 7 new shims. I'm just waiting on them to come in.

By the way; for anyone else changing shims, you may see some posts out there that say you can just use a couple of screw drivers to push down the valve and pop out the shim. This is near impossible to do unless you're Hurcules with 4 arms. You will either need the special shim removal tools or do like I did and just take the camshafts out. It's really not that much more work to take them out and then taking the shims out is a breeze.

In regards to my "hot start" issue. I did take off the fuel pressure vsv and tested it per the TSRM. It passed the electrical test, but when I tried blowing air through it, it seemed like it wasn't flowing freely. I thought maybe I could clean it out with some brake cleaner. Bad idea, that made it even worse and now no air will pass through. Naturally this is a discontinued part so I took the advice of another thread and will be using Dorman part 911-604 to replace it. I will have to see if that fixes the hot start issue.

 

[slowerisfaster]

Update:

The engine is back together again. The good news is that the idle is perfect now and the car is running great. I can finally turn my attention to other items that need addressing (I know, I know there will always be something that needs to be done).

Now the bad news. I replaced the fuel pressure VSV as Suprarx7nut advised, but my "hot start" issue remains. I read on another thread somewhere to try and disconnect the coolant temperature sensor connector while this problem is occurring to see if it helps. I did that, but it did not have any effect.

I guess my question is what to look at next as the most likely culprit? Then I can proceed to diagnose whatever that is.

 

[suprarx7nut]

Quick comment on the shim removal: Agreed. Replacing some of the shims is a breeze, but others are very difficult with the cams in car. I had a special tool and even then it was terrible. Taking the cams out is far easier and faster.

 

[Koenigturbo]

wow I didn't know we needed red coolant...

As the title says I am getting ready to do a rebuild of the head in a couple of weeks. I have done a LOT of reading on this subject (thanks to this forum and others) and feel pretty confident that I will be able to complete it without much trouble. Since this will be the furthest I've dug into an engine bay I would like to make sure I haven't missed anything as far as the parts list goes. If you guys wouldn't mind taking a look at what I've ordered so far and make any suggestions, I would appreciate it. Here goes:

1987 Supra Base W/ Sport Package - 5spd manual - 7M-GE - 55,000 miles

1. Top end gasket set (will NOT be using the provided head gasket)
2. OEM Toyota head gasket
3. Water pump
4. Thermostat
5. Timing belt w/ tensioner
6. ARP head studs
7. M12 x 1.25 Thread Chaser
8. M10 x 1.25 Helicoil Kit (for the exhaust studs)
9. 10mm Hex Socket (long) for removing stock head bolts
10. 14mm 12 Point Deep Socket for installing ARP studs
11. Dino oil (not synthentic) for break in
12. Toyota red coolant
13. Spark plugs

Did I miss any parts? Are there any other SPECIAL tools I will need? (I have a torque wrench already)

I will be having a machine shop do the actual work on the head; I'm just removing and reinstalling. I am still debating if I should have them do a mild port 'n polish. From what I've gathered by searching it looks like I should NOT have them do the exhaust side; only the intake side. Can someone confirm this?

Thank you for your help.

 

[plaaya69]

Yes the factory red coolant is very good quality. As for that green stuff I have seen bad results from others. If you can't get a hold of the factory red coolant, Valvoline Zerex Asian vehicle coolant is a better alternative to that green coolant as well.

 

[Koenigturbo]

Thank you again Plaaya 69!

Yes the factory red coolant is very good quality. As for that green stuff I have seen bad results from others. If you can't get a hold of the factory red coolant, Valvoline Zerex Asian vehicle coolant is a better alternative to that green coolant as well.