ok my car is still bucking badly and stalling out. i replaced MAF(or VAF),CAS,TPS,cap,rotor,plug wires,plugs with all new units. nothing really changed anything except the CAS. after i replaced it the car runs worse (although the ignition timing might be a slight bit off now) what else would cause this much of a problem? i am unbelievably frustrated at this point and really hope someone actually has an answer

Injectors?
some vacum lines fallen off? even crank vacum can **** alot, dip stick seal..
right and clean fuel?

it bucks extremely bad i dont think one injector would cause that and i dont think they are all bad. i will check vacuum lines but i have never heard of a vacuum leak causing bucking this bad. could it be a bad coil or module? it seems like the module will either work or not at all. the car does run (barely)

What do you mean... bucking?

Like a miss fire, or the engines jolting on its mounts every so often?

I had a frustrating problem with my 1600 when it would occasionally run rough as guts and the engine would splutter and miss especially when i was putting the boot in, it ended up being the rubber boots that surround the lead ends on the plugs were missing and the spark was earthing out into the FJ's deep head

Worth checking, I run a EMS so am unsure bout standard ECU issues. My only other suggestion would be fuel, fuel pumps, filters, lines... Clean or replace it all

Its cheaper to replace stuff to get it running better than to let it go to sht

Any chance the CAS is worse than your previous sometimes thats why they get sold...

Vac leak is always a problem even the smallest hole or split will play havoc wwith fuel pressures

If your talking the engine jolting, then it could be more serious and nothing less than taking it out and looking under its skirt should occur, much better to prevent further damage. Something like a screwed chain tensioner can make the chain slap and jump teeth, cams being slightly out can cause some nasty piston to valve issues

I know it costs but get a good dyno tune, get tunning spot on and check fuel pressures

Simon

let me clarify what i mean by bucking. here is an example. i start the car, idle is a bit rough, idles up to 1.5k then back down to about 600 randomly. i start driving car will rev up to a point (this point varies but is always between 0 and 3000rpm because it will not rev any higher) once it reaches these random points it will cut out for about 2 seconds each time then all of a sudden it will either kick back in or stall out completely. this problem gets worse the longer the car is running (the at idle and driving). when it cuts out its like it was completely shut off i can floor it or pump the pedal and nothing will happen until roughly 2 seconds has passed. hope this helps a bit

sounds like teh maf to be,

check the plugs going into the actual plug and the double plugs a little bit back on the loom (i know only some cars have those)

any way i can test the plug going into the maf with a volt meter? if there is how should i do this and what voltage should i look for?

i cleaned everything out and checked the wiring/ lines and everything seems good but i am still having the same problem im ready to give up

have u put a mutli-meter on the fuel pump?
i had this prob and it turned out my fuel pump was getting 7v not 13 or 14 like it should
maybe check that, also do a fuel return test to make sure the fuel pump
is working how it should might be a fooked pump,

hope this helps cheers,mike

i will check voltage but it is getting enough fuel (plugs are sooty black which means rich mixture, right?) i was talking to a japanese guy today with some experience with fj's he said it might be the coolant temp sensor? anyone had a problem like this caused by coolant temp sensor?

Well, yer it can cause the ECU to run rich if the sensor has died. But to kill the engine for some seconds and then let it run again....mmmmmmmmmm?

You mention the drama got worse AFTER you replaced the CAS.

You have changed most things which will cause this drama except the ingition trigger transistor. The metal can thingo on the coil.
See if you can find an alternate one from older Saab's and Volvos (Bosch 008/BIM137 or equivalent)from a wrecker and give that a try.

The stock Nissan transistor is a pretty reliable item but very expensive to replace hence the Bosch equivalent.

After that and before you replace the ECU, youll need to go thru your wiring and look for bad earthing between the engine and the battry/chassis.
Bad earth side bonding can cause all sorts of hassles.

After that and that........well!!!!! It might be off to an EFI specialist.

L8tr
E

NEW SYMPTOMS!!: after trying everything i can think of short of ripping into the engine (gaskets are hard as hell to come by for an FJ) the symptoms are now: when i go out to start the car after letting it sit over night it will start up right away and have a slightly unstable idle and will sometimes stall out if i dont press the gas a bit. it will rev all the way out to 7k with only a slight bog and little sputtering but within 2 minutes of running the car it will not rev out for **** and cuts out for 2 seconds at a time and barely idles like before. under load it is even worse. the plugs are still very sooty and black but never wet.

someone new looked at it today and said that there were two cap and rotor set made for the fj depending on the distributor and he said its very common for them to swap out distributors when the CAS goes bad so it might just have later model distributor in it and i put an old model cap and rotor on it because they used my title to order it. so i am in the process of ordering a new cap and rotor we will see if that is the problem. anyone else had this problem before?

Ive had trouble finding a replacement dizzy cap
All i seem to be able to find is the screw on ones... i need the one that is held on by 2 clips - anyone got part numbers?

I've also had trouble with temp sensor - the plug came half way off after a high speed run, made it undrivable at low speeds, cutting out all the time... it must have been getting signal on and off rapidly which caused havoc

that sounds like my car. i replaced the coolant temp sensor and it still did this though. it seems like my car has a few of them though. one on the block (not including the temp gauge sender) one one this metal tube spliced into my top radiator hose. one on the bottom of the radiator (that isn't hooked up) and one on the top of the radiator (i think this one is hooked to the fans though)can someone clarify what these all do or which ones i need for the car to run correctly.

well i was working on my car a bit today with a friend and he figured out that it runs fine in open loop cold start but when it goes into closed loop that's when all the problems happen. right when it goes into closed loop it seems to get really rich then stall out (or possibly really lean to the point where it dies, its hard to tell because the plugs are always sooty black) so it would appear to be related to a sensor or ecu problem. i have replaced all the sensors besides the 02 sensor. would that cause it? my car doesn't do the weird erratic idle thing that most cars do when they have a bad 02 sensor though. is there any way to test the 02 sensor? it is a 1 wire unit. also the air meter is a new unit intended for a 280zx turbo it looks exactly the same and has the same plug and numbers above the plug input. would this be the wrong air meter?

Wild guess -- does the car have a catalytic converter? Could it be partially plugged up?

no it just has a test pipe. i tested that too. i disconnected the exhaust right at the end of the down pipe and ran it. same problem so its not an exhaust plug