Another 4runner won't start thread! I've read them all...

[a_young240]

So I'm hoping someone here has some input, any input or questions welcome - we're out of ideas... I've read other threads on this forum and others with not starting issues, but it seems they have a lack of fuel or are not turning over at all. Here's the scoop:

We bought a 1996 Limited 4runner 3.4L V6 (5VZ-FE) with a blown head gasket and some other small issues and had it towed home. Following this we pulled the engine so we could give it and the engine bay a nice cleaning, as well as have easier access to replace parts and set the timing. We cleaned it all up, installed the head gasket kit and shoved it back in the 4runner... well as you know, now it won't start (in both park and neutral). Here's a list of things we've replaced along the way:

Head gasket kit, all of the belts, radiator & rad hoses, starter, battery, oil pressure sensor (from junkyard as the wire was severed accidentally in the pull), plugs & wires, water pump & thermostat, ECU, some fuses, rear shocks... I might be forgetting one or two things, but that's what I remember off the top of my head.

The original battery was dead, but it was jumped on the lot and it started fine. Along the way of trying to get it started, someone tried to put a temporary battery in from another truck to see if it would start and the poles were reversed, so for a second it back-fed the system. I went through and checked all the fuses and relays (replaced some fuses) and because nothing else was working thought maybe the ECU was hurt in the process - replaced it with a tested one from the junkyard for $100. Still nothing...

At the current moment it is sounding sooo close to starting... turning over fine and getting fuel to the engine (we cranked it while the fuel line to the engine was in a container and gas puked out, as well as the plugs smell like gas when you pull them). We've double and triple checked that it is in time and there's been spark when we ground a pulled plug.

We just found out the previous owner installed a CompuStar alarm/keyless entry/remote start/passive immobilzer at Future Shop. I thought that this was the answer for sure! I called Future Shop Installs and they said it is impossible for that to be the issue because it wouldn't even turn over if it was immobilized. Regardless, the keyless entry has to be fixed because the remote doesn't do anything. I tried turning the ignition 5 times blah blah blah to reset the remote and it clicks and beeps but at the end it still isn't pairing.

Please help! Any ideas?

 

[kball]

You've got spark and gas to the cylinders and it won't fire? Are you sure the air intake isn't stopped up?

 

[a_young240]

Pretty sure, but I will double check. I know what you're saying, though. An engine only needs a finite amount of things to fire and run. It sounds so close, it wants to but just isn't.

 

[kball]

If it's actually firing here and there but not consistently enough to fully run, I'd look at the timing again. Also make sure things like the crank and cam sensors are plugged in.

 

[a_young240]

Thanks, I will look at the crank and cam sensors. They are plugged in, but perhaps one of them has failed (seems strange that they would in this short amount of time, but you never know!)

The timing is good - we pulled the timing belt and re-did it just in case (looked ever so slightly out before)

 

[SV_Dude]

Did you double check your vacuum lines to make sure you have them all plugged back in and in the right order? Double and triple check your timing too.

 

[a_young240]

Timing is double and triple checked and the vaccuum hoses are correct. I realize it has to be something we're over-looking. Cam and crank sensors seem like the most valid option so far. Perhaps double check spark on the rest of the cylinders

 

[SV_Dude]

I could be wrong but if you have verified that you are getting fuel land spark while cranking the engine and you are getting air then got electrical side of the house should be good and the only thing left would be timing or some major air leak somewhere.

Have you pulled a spark plug after you tried to crank to see if they're wet with fuel?

 

[the great him]

ok so if you pulling plugs and they smell of fuel that tells e that you are 180* out on timing... it would look correct visually on the inspection but your crank would be one turn off. ie you are putting fuel into the cylinders on the exhaust stroke, and thats why it wont fire. its sounding close, because there is still residual of fuel in the cylinder when the compression/ignition stroke comes around but yeah not enough to make the motor run, and not enough to completely burn all the fuel. i think thats why you get the fuel smell on your plugs


if you have checked for that already and are 500% sure thats not it, then check all of your grounds, you might have a ground thats not hooked up. or check your MAFS, or check your intake for any leaks.


but my gut is telling me that the timming is 180 out by your discription

 

[a_young240]

Hmmm, interesting. So you're saying the timing of the cams is most likely out?

Perhaps we're interpreting the FSM incorrectly. We placed the cams at 2 dots and 1 dot... Is right and left viewed from the driver seat or standing in front of the engine? We did 2 dots to the RH (passenger side).

The timing belt itself is good - the crank was at 0* TDC and the cam pulleys were also both aligned to the top marks when the belt went on.

 

[a_young240]

Noticed another issue. Another symptom, or perhaps a separate issue I have to fix?

We replaced the original battery with a new one, but just yesterday took that new battery back as it was not holding a charge - we thought it had some bad cells or something. But now this new replacement battery sounds drained as well when we try to start up the 4runner. There is something that is sucking the life out of these batteries in a quick fashion. From the other threads I've just read on parasitic drains, it seems like a separate problem, but who knows...

 

[the great him]

Hmmm, interesting. So you're saying the timing of the cams is most likely out?

Perhaps we're interpreting the FSM incorrectly. We placed the cams at 2 dots and 1 dot... Is right and left viewed from the driver seat or standing in front of the engine? We did 2 dots to the RH (passenger side).

The timing belt itself is good - the crank was at 0* TDC and the cam pulleys were also both aligned to the top marks when the belt went on.

no not the cam gears, leave those as they are(be careful, as they are spring loaded, and will want to jump one way or the other about 1/4-1/3 of a turn if they are bumped... make sure you rotate them back to their correct position if they do jump), but rotate the crank one full revolution, and try that. if that does not solve your issue rotate it once more to put it back the way it was initially. but i think some how initially it got rotated or other wise out of rotation with everything else, and thats why you are having this issue. it would visually look correct and in perfect timing -even with a timing light, but it would be "180*" off timing. -the good thing is this motor is a non-interference motor so you cant hurt it with the timing being off

Noticed another issue. Another symptom, or perhaps a separate issue I have to fix?

We replaced the original battery with a new one, but just yesterday took that new battery back as it was not holding a charge - we thought it had some bad cells or something. But now this new replacement battery sounds drained as well when we try to start up the 4runner. There is something that is sucking the life out of these batteries in a quick fashion. From the other threads I've just read on parasitic drains, it seems like a separate problem, but who knows...

this sounds like a bad ground, if go through and check all of your grounds, you pulled the motor so you might have forgotten or over looked a ground somewhere. and if you have any questions at all or if you think the battery cables might be the original cables, replace them, sometimes they can corrode from inside out, like down inside the sheath and you would never be able to visually check or see it. id check all grounds, and all cables to and from the battery, as they will be the prime suspect for the drain. it is also possible that if the cables or grounds are the original ones you might have bumped one in such a manor as to break it inside and that is creating the short/draw. take a volt/ohms meter and test the current/resistance of the wires/cables that will tell you if they are bad.

you could have broken a wire to the crank sensor or a cam sensor which could also be causing both of these issues, its shorting out and draining the battery and not sending a good signal to the ECU so the motor wont fire.

these are all just educated guesses based on your description of work done and the issues you are having. its hard to pinpoint exactly what it is 2000 miles away over the internet. good luck and keep us updated

 

[a_young240]

I appreciate all the insight. I will do some more digging and update this thread in the near future.

Cheers!

 

[hambob]

Compression check would rule out a lot of possible valve and timing issues. Might point you in the right direction. Its cheap too!

 

[TheDurk]

ok so if you pulling plugs and they smell of fuel that tells e that you are 180* out on timing... it would look correct visually on the inspection but your crank would be one turn off. ie you are putting fuel into the cylinders on the exhaust stroke, and thats why it wont fire. its sounding close, because there is still residual of fuel in the cylinder when the compression/ignition stroke comes around but yeah not enough to make the motor run, and not enough to completely burn all the fuel. i think thats why you get the fuel smell on your plugs


if you have checked for that already and are 500% sure thats not it, then check all of your grounds, you might have a ground thats not hooked up. or check your MAFS, or check your intake for any leaks.


but my gut is telling me that the timming is 180 out by your discription

The crank doesn't matter to exhaust vs. compression, that's up to the camshafts. The crank turns over twice to each revolution of the cams. If you turn the crank over once and retime, it won't make any difference, assuming you did it right the first time. It will just be at TDC, just as it is twice in every cycle. The fuel injection is timed by the ECM off the cam position sensor, so the crank has nothing to do with that.

But, timing may still be an issue. TheKid is certainly right that if you have spark, fuel, and compression, timing is suspect #1 that is left. Is there any chance the crank key was left out and the sprocket is not lined up? Long shot, but at this point you are looking for those. Also check for any damage to the crank and cam sprockets. A broken tooth can screw up timing. Finally, if you can find a timing light somewhere, you can check ignition timing while cranking to rule out any issue there. Also put the timing light on the other two wires, just to be sure they have spark.

My personal nomination is for crossed plug wires. I post this a lot, but I'm going to do it again:

If all this checks out, go back over all four again--spark, fuel, timing, compression. Have you tried a compression check? It seems unlikely but again, not much is left.

My last long shot is a plugged cat. That will also do it.

 

[the great him]

The crank doesn't matter to exhaust vs. compression, that's up to the camshafts. The crank turns over twice to each revolution of the cams. If you turn the crank over once and retime, it won't make any difference, assuming you did it right the first time. It will just be at TDC, just as it is twice in every cycle. The fuel injection is timed by the ECM off the cam position sensor, so the crank has nothing to do with that....

umm wouldnt the crank position sensor be getting tripped at the wrong time relative to the crank sensors if one was one or two full turns ahead of the other?

but yeah i guess a cam being one turn out would also cause the motor to not fire as well

 

[TheDurk]

umm wouldnt the crank position sensor be getting tripped at the wrong time relative to the crank sensors if one was one or two full turns ahead of the other?

but yeah i guess a cam being one turn out would also cause the motor to not fire as well

A cam can't be one turn out. That just means it is starting a new turn. The cams are on exhaust (on cyl 1) when the timing marks are at 180°--at 6 o'clock. At that point, the crank is back at TDC, starting its second turn. There is no difference in what the crank does on its first turn from the second. Pistons go up, they come down. Then they do it again, cycle over.

You would get ignition timing out by 180° on older cars when you would replace a distributor and the engine would be at TDC but on the exhaust stroke (been there, done that). You would have to put your hand over the #1 plug hole to insure you have compression and not exhaust before installing the dizzy.

I don't know how you get 180° out on this engine, on anything, if you have correctly installed the TB to the marks and the sprockets/pulleys are true on their shafts. The sensors take care of the ignition and fuel from there off the little magnets in the sprockets/pulleys.

 

[mmml4]

umm wouldnt the crank position sensor be getting tripped at the wrong time relative to the crank sensors if one was one or two full turns ahead of the other?

but yeah i guess a cam being one turn out would also cause the motor to not fire as well

It seems like I read a few days ago that the crank sensor generates 34 pulses per rev of the crank so its steady signals not just one if thats what your thinking.

 

[the great him]

A cam can't be one turn out. That just means it is starting a new turn. The cams are on exhaust (on cyl 1) when the timing marks are at 180°--at 6 o'clock. At that point, the crank is back at TDC, starting its second turn. There is no difference in what the crank does on its first turn from the second. Pistons go up, they come down. Then they do it again, cycle over.

You would get ignition timing out by 180° on older cars when you would replace a distributor and the engine would be at TDC but on the exhaust stroke (been there, done that). You would have to put your hand over the #1 plug hole to insure you have compression and not exhaust before installing the dizzy.

I don't know how you get 180° out on this engine, on anything, if you have correctly installed the TB to the marks and the sprockets/pulleys are true on their shafts. The sensors take care of the ignition and fuel from there off the little magnets in the sprockets/pulleys.

ill check but im sure these motors can be 180 out/off what ever you want to call it. other wise you could just do what ever you wanted as long as the marks are lined up and be good. and i know that is not the case. you can not turn the cams or the crank independently of each other [without matching the rest] and expect the motor to work... that would be great if you could but im pretty sure i cant just go start spinning a cam gear(or crank) how ever i want and then think that as long as i get the mark lined back up im good to go.

ill double check on this but im pretty sure everything has to get lined back up in sink with everything else

 

[the great him]

It seems like I read a few days ago that the crank sensor generates 32 pulses per rev of the crank so its steady signals not just one if thats what your thinking.

i think your right, but if that signal is being put out at the wrong time in correlation with everything else...


im not trying to argue that its timing(ok i sorta am) but im just trying to completly rule out timing as the issue -yes i know the OP has stated he has checked the timing and the marks all line up... but i still think there is a risk of being in the 12 noon instead of the 2400/000 time -they all look the same if your in a room with no windows