Hey Everyone
I am having problems starting my 88 V6 4Runner. It turns over fine and sputters on ocassion, but not much. I checked the diagnosis system and there are no codes. The fuel pump is working and I am getting good spark.
What could be wrong? Have I overlooked something?
Could it be possible that the timing belt slipped or snapped?
Thanks in advance for your advice.
Dylan
sputters on ocassion, but not much. I checked the diagnosis system and there are no codes. The fuel pump is working and I am getting good spark.
Compression Check?
Possible. A compression check could help reveal that as well (i.e. cylinders with open valves have no compression, etc).
All sorts of reasons. Start with a compression check.
lycka till! GTr
sputters on ocassion, but not much. I checked the diagnosis system and there are no codes. The fuel pump is working and I am getting good spark.
Not sure how you know your fuel pump is "working" - unless you have checked the pressure (~40 psig).
If you are concerned about the timing belt, you can put a wrench on the crankshaft bolt and turn it until the timing mark on the pulley assembly is pointing at 0°. The rotor button on the distributor should then be pointing dead at a 'tab-like extension' on the mounting face of the distributor. If it's pointing in the opposite direction, that's okay - turn the crankshaft another revolution. You will need to remove the fan to get to the crankshaft - or you could have someone hit the ignition and try to get lucky. If you use the wrench method, only turn the motor in the clockwise direction.
If you haven't been changing your timing belt every 80K or so, it's not a bad bet that it could have broken or jumped. There is no negative interference with the valves on these motors, so you won't have heard them hitting the pistons.
Other than that, if you are sure that you are getting good spark and gas flow, you should check for a serious vacuum leak in the air intake line followed by checking the air flow meter. There is a fuel pump swith in the AFM that can be checked as well as other settings, all with an ohmeter. This is done at the connector.
I can give you the correct readings between the various terminals if you like.
Luther
sputters on ocassion, but not much. I checked the diagnosis system and there are no codes. The fuel pump is working and I am getting good spark.
I had a timing chain jump once ('69 Firebird) and the engine spun like a sewing machine when cranking because there was no longer any compression for the starter to work against. It was quite odd.
Compression check is good idea if you feel good about spark, fuel, and induction (including no vacuum leaks). What you describe could be burned valve(s) which would show up in a compression check. When mine needed a valve job -- suprisingly -- it wasn't a gradual thing at all. The drop in performance (it ran, but poorly) happened so suddenly that my mechanic was certain it was an electrical problem and spent many hours looking for shorts in the wiring harness before he finally realized he was on the wrong track completely.
Luther
Hey
I verified that my timing belt is not snapped and also has not slipped any of the cam or crank gears. I also used my ohm meter on the Mass air flow sensor and it is giving perfect readings.
Having a vaccum leak is a possibility although I do not have a vaccum pressure gauge. How can I go about testing this?
Thanks
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