86' 4-runner not starting. ANY ADVICE????

[fireman105]

Turns over and will almost start but then just spins. Was doing the same thing when I parked it but eventually would start. It has run hot before when dash lights went out one time on interstate and could not read the temp ga. at night. Had to park it that night but went back, put water in it and it crunk up and drove it home. Ive been rebuilding the truck using parts off a donor truck so its been siting up for about 5 months. new plugs, wires, dist. cap and button. compression looked good. I was thinking cold start inject. but still starting fluid should help it start even if its bad right? did notice oil is a little milky but not that bad, timing chain guides look good tho. maybe warped head or blew head gasket when ran hot, but it should still crank right? Injectors? fuel pressure? Anyone got any adviCe here?

 

[topdown4runner]

I had an 86 with a bad head gasket.
Sounds like your truck. Started out being hard to start, then would not start at all.
Milky oil is a big clue.
Good luck!

 

[88T4RE]

don't know why it doesn't start sorry but the head gasket is definitely gone...

 

[the_dingman]

Spinning is usually from either no compression (blown head gasket, rings, etc) or it could be a bad starter or flywheel.

 

[fireman105]

Head is off now. Confirmed water in oil. Could not see a blow out or other damage on gasket. Taking head to machine shop today to get tested. timing chain guides in place and timing has not jumped. Hope to know something soon. Still puzzeled why it would not at least start???

 

[Getsum]

Head is off now. Confirmed water in oil. Could not see a blow out or other damage on gasket. Taking head to machine shop today to get tested. timing chain guides in place and timing has not jumped. Hope to know something soon. Still puzzeled why it would not at least start???

Did you hook up a compression gauge to each of the cylinders prior to tearing it down? This is the ONLY way to know if your compression is truly good or not. Since you only have 4 cylinders to begin with, a substantial leak in one or more of the cylinders from a blown gasket would prevent sufficient compression, thus not allowing it to start.

Can you post pics of both sides of the gasket? Oftentimes, it takes a trained eye to see where the leak occurred. (I'm not saying I'm the master here...but I'm sure we can collectively find a cause)..sometimes it is a glaring fault in the gasket, other-times it is a minor defect that can still cause total failure.

 

[fireman105]

Compression was 145, 145, 155 and 165. Did notice today when I took to machine shop burn marks on head where cylinder meets head and could tell where water was hitting valves on two of the cylinders, so def. leaking. I'm assuming I was getting water sucked in on decompression fouling plugs or diluting fuel mixuture? Should have head back tomorrow.

 

[fireman105]

Its officail, head is FUBAR!!!!
Plan B in progress

 

[Getsum]

Its officail, head is FUBAR!!!!
Plan B in progress

Plan B a supercharged V-8?

 

[fireman105]

Hell yeah!!!

 

[fireman105]

Should start installing new head next week. Are there Any other misc. parts I should replace while I have it tore down? I hear ppl talk about the knock sensor. What does this actually do? and should I replace it?

 

[turboSR5]

A new timing kit install would be a good idea, check engnbldr.com for a good kit for a good price. I wouldn't worry about the knock sensor unless you know there is a problem with it.

 

[fireman105]

Ok, head is back on and everything done to spec. Still very hard to start cold. How do I diagnose the cold start injector? also not getting a reading on oil pressure gauge?

 

[90toytruck.]

Plan B a supercharged V-8?

lol funny way funny

 

[SKIDPLATE]

When you said NEW plugs etc, did you mean really new or new from the donor, and did you do this before of after it overheated? What is the compression now? Does it still not start at all or just not start very well? Did you check the fuel pump?

 

[FubarGrn]

Its officail, head is FUBAR!!!!
Plan B in progress

I am not your head!

hehe, in all seriousness, sorry to hear about the head m8, but whilst ya got it down, think about getting the head gasket matched//ported + polished. Maybe get the machine shop to machine the heads for those tasty fel-pro LoC-wire gaskets (the ones with the raised copper gasket reinforcement. In case you ever wanted to Boost it (supercharger/turbo/nitrous).

ahh breakage, a real good reason to upgrade!

 

[salty]

Ok, head is back on and everything done to spec. Still very hard to start cold. How do I diagnose the cold start injector? also not getting a reading on oil pressure gauge?

The oil pressure gauge problem may be just cause you forgot/or missed pluging the sending unit back in. Look for a wire that is not pluged in to anything. will have a female "bullet style" connector on the end this connects to the sending unit. Now the hard start problem dose the engine turn over easy or dose it t-u-r-n o-v-e-r slowly... If it cranks fast your timing is over advanced and you need to reset it correctly. The same if it is dragging or slowly turns over, thie timing is re****ed and still needs to be reset correctly to spec. if the timing is correct Check the Pick up in the distributor this part sends a signal to the injectors on when to spray,as well as the plugs on when to fire. Hope this helps.