Look on the wire bundle that goes over the timing belt cover and feeds several wires to the distributor, the oil pressure sender, and the a/c connector. The oxygen sensor connector should be in there
Help please reassembling engine
I just finished putting back together the engine of my 1987 MR2 (with 260,000 miles) after replacing a head gasket. Everything else, including the pistons, cylinders, and rings, were in mint condition!
When I got to the end, there were two things I couldn't figure out. First, there is a black plastic piece on the front side of the intake manifold with three nipples for vacuum lines. One I hadn't removed, but the other two tubes are hanging free, and two of the nipples are unoccupied. One line comes from the right front, the other comes from the left front, and I don't know which was attached to which nipple. Can anyone with a 1987 MR2 take a peek and tell me?
The second is more embarrassing. I can't find the socket to plug the oxygen sensor wire into, even though I've searched from under the car in the vicinity of the sensor (on the exhaust pipe). Can anyone give me a clue about where the plug (round black plastic with a single wire) goes?
Thanks for any help! I hope to get my MR2 up and running soon.
When I got to the end, there were two things I couldn't figure out. First, there is a black plastic piece on the front side of the intake manifold with three nipples for vacuum lines. One I hadn't removed, but the other two tubes are hanging free, and two of the nipples are unoccupied. One line comes from the right front, the other comes from the left front, and I don't know which was attached to which nipple. Can anyone with a 1987 MR2 take a peek and tell me?
The second is more embarrassing. I can't find the socket to plug the oxygen sensor wire into, even though I've searched from under the car in the vicinity of the sensor (on the exhaust pipe). Can anyone give me a clue about where the plug (round black plastic with a single wire) goes?
Thanks for any help! I hope to get my MR2 up and running soon.
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one of the vacuum lines should be to the fuel pressure regulator
As said before there should be a bundle that ran in front of the timing cover. It should be the longest plug.
That three nipple thing is a vaccuum port. Only one of the three are used as you observed. Inforget what it was used for. Ill check when I get home
That three nipple thing is a vaccuum port. Only one of the three are used as you observed. Inforget what it was used for. Ill check when I get home
Yes that plastic thing with the three prongs goes into the intake manifold. ( you made it sound like its removed) and then to the fuel pressure regulator on the left ( drivers ) side of the fuel rail. The hose connects to any of the three ports as all it does is split the pressure.
I've always wondered what would happen if there was no vacuum on that line? would the pressure build out of control? Would it just not recirculate? I guess it technically has no vacuum when you're at WOT because the intake is at atmospheric air pressure.
I'll admit I was expecting much more disastrous questions from a thread with the title HELP PLEASE REASSEMBLING ENGINE.
lol
Did you do anything else usefull while replacing the HG? things to consider would be the cam seals and all the timing belt stuff. Maybe even checking your valve clearance and looking for some new shims I'm sure after 260k its way out of spec if its never been adjusted.
I've always wondered what would happen if there was no vacuum on that line? would the pressure build out of control? Would it just not recirculate? I guess it technically has no vacuum when you're at WOT because the intake is at atmospheric air pressure.
I'll admit I was expecting much more disastrous questions from a thread with the title HELP PLEASE REASSEMBLING ENGINE.
lol
Did you do anything else usefull while replacing the HG? things to consider would be the cam seals and all the timing belt stuff. Maybe even checking your valve clearance and looking for some new shims I'm sure after 260k its way out of spec if its never been adjusted.
Yes, thanks! I looked under the distributor with a mirror and found the socket for the oxygen sensor. It was not directly visible either from above or below.Look on the wire bundle that goes over the timing belt cover and feeds several wires to the distributor, the oil pressure sender, and the a/c connector. The oxygen sensor connector should be in there
Finding this was especially lucky because I also found a second pair of green plastic male and female electrical connectors. I had connected one visible pair (1 & 2) to each other; I realized I had overlooked the second pair, and that 1 should connect with 4 and 2 with 3!
So if I understand you, all three ports on the vacuum module have the same function, and I can connect the three pieces of tubing to any of the three nipples.Yes that plastic thing with the three prongs goes into the intake manifold. ( you made it sound like its removed) and then to the fuel pressure regulator on the left ( drivers ) side of the fuel rail. The hose connects to any of the three ports as all it does is split the pressure.
I've always wondered what would happen if there was no vacuum on that line? would the pressure build out of control? Would it just not recirculate? I guess it technically has no vacuum when you're at WOT because the intake is at atmospheric air pressure.
I'll admit I was expecting much more disastrous questions from a thread with the title HELP PLEASE REASSEMBLING ENGINE.
lol
Did you do anything else usefull while replacing the HG? things to consider would be the cam seals and all the timing belt stuff. Maybe even checking your valve clearance and looking for some new shims I'm sure after 260k its way out of spec if its never been adjusted.
And to your last question, yes and no. I thought while I was removing the head off I should check a bunch of other things. I checked the valve clearance. One of the 16 valves had a clearance just out of spec (0.254 mm; normal range 0.15-0.25mm), so I put in the next larger shim. All the other valves were still in spec after 260,000 miles!
I went ahead and dropped the oil pan so I could check the cylinders, pistons, and rings without removing the engine block, figuring as you did that they probably needed work. All three were perfectly within original specs! However, since I had taken the pistons out, I deglazed the cylinder walls and replaced the rings. I also replaced the crankshaft and connecting rod bearings, which showed very slight signs of wear.
I inspected the valves with much the same result. The intake valves were pristine. The exhaust valves had a few small pits that didn't span the sealing surface, so I decided to leave well enough alone and didn't grind anything. I did replace the valve stem seals on principle (and I'd already ordered replacements along with the head gasket and bolts). I'll see if I was right to leave the valves alone once it get the engine running again; I had checked the compression several months before the head gasket blew, and all cylinders were fine.
Thanks again to everyone for the help and support!
Anyone have any idea why the head gasket blew out? I'm still mystified as to why this happened (my son was driving the car, and he said that with no warning great clouds of steam/smoke came out of the engine compartment and the engine stopped). I confirmed that one edge of the head gasket was blown out when I took the head off, but I don't know what caused it. I've checked the thermostat and flushed the cooling system, and all that seems noramal.
Ok, wow, you did alot more than I was expecting. Awesome work.
Very solid decisions and more than I would have done. I'm sure your engine will continue to run well in your hands.
You are correct that any of the three ports will function identically. it is a splitter. Likley designed by toyota for a vacuum application that never got used.
What caused the head gasket to fail? The car is close to 30 years old. Thats probably it. Also the Iron block to aluminum head combination is known to cause unequal warping of both parts which creates an imperfect seal and blows head gaskets. Could it be your engine overheated? Otherwise a rapid blow like that is unusual. A slow leak is much more common in the world of HG failures.
Was your son redlining it between 2nd and 3rd gear all day? lol.
It's just that I'm 19 and know how kids can drive cars... ha.
Very solid decisions and more than I would have done. I'm sure your engine will continue to run well in your hands.
You are correct that any of the three ports will function identically. it is a splitter. Likley designed by toyota for a vacuum application that never got used.
What caused the head gasket to fail? The car is close to 30 years old. Thats probably it. Also the Iron block to aluminum head combination is known to cause unequal warping of both parts which creates an imperfect seal and blows head gaskets. Could it be your engine overheated? Otherwise a rapid blow like that is unusual. A slow leak is much more common in the world of HG failures.
Was your son redlining it between 2nd and 3rd gear all day? lol.
It's just that I'm 19 and know how kids can drive cars... ha.
On this website there are excellent photos that were very to me when I reassembled my engine compartment: http://www.pbase.com/aw11mr2/root&page=all
I'm really surprised that it hasn't needed a head gasket before now. Lots of people don't replace antifreeze ever, so you end up with lots of sediment over time keeping it from being cooled as designed. I'm reluctant to say if the boy "caused" the problem as it could have been weakened over time and a bit of enthusiasm could have just been its excuse to give out. Because the milage is high and if the boy is generally honest and not a lead foot to accept the head gasket blew like he said. The problem with kids is its easy to assume a boy drove it too hard where you might assume a girl ran it out of oil. On the plus side you probably just lost the puff of smoke on startup.
Thank you, thank you! This is outstanding. Picture # 7955480005 shows exactly the picture I should have taken before starting disassembly, and shows the vacuum tubing coming from the right side of the car going to the top port on the vacuum module. The tubing from the left, while not visible, must therefore go to the bottom port. Whether this makes any difference or not is unclear, but I'm more comfortable putting things back where they were originally.On this website there are excellent photos that were very to me when I reassembled my engine compartment: http://www.pbase.com/aw11mr2/root&page=all
No, but you will have excess fuel pressure under most circumstances. The regulator is supposed to set the pressure across the fuel injectors, and since the injectors have there noses in the manifold, it cannot do that unless it has a sample of the manifold pressure to work with....I've always wondered what would happen if there was no vacuum on that line? would the pressure build out of control?
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