Underpowered Bigport 4AGE

[Gavatron]

Had this problem ever since I bought the car. Did a full service on the car and then ran it on the dyno. Received a lackluster 43fwkw.

After this effort I decided to check the timing. After shorting the correct pins I checked the timing to see it at 20btdc. Timing is meant to be at 10btdc when the pins are shorted.

So I undid the adjusting bolts to turn the dizzy, to find that the timing could not be retarded any more than it already was!

After this I undid the dizzy and changed it one tooth and reinstalled it. Now with the adjusting the most I could advance it was 0 degrees (TDC).

Also checked the cam timing. All the dots line up on the cam backing plate and on the crank pulley. Also changed the crank pulley and checked the key on the crank cos I was told they fuck themselves out after a while. It's in perfect nick.

So my question is, what the hell is wrong with my 4AGE? I can't get the timing anywhere between 0' and 20'btdc. It is currently running on the 20'btdc but is underpowered something chronic. Revs all the way out but goes nowhere fast.

Suggestions?!

[30psi 4agte]

Hmmmmmmmm

Does the timing change when you bridge the terminals ????
IE if you check it at idle without terminals bridged is it the same as when they are bridged ??

[Gavatron]

The timing changes. You can hear the idle drop slightly. Meaning that when the pins aren't bridged the timing is advanced even more than the displayed 20'. Doesn't ping though.

[30psi 4agte]

Doubble Hmmmmmmmm


All i can think of at the moment is ....... Has the dizzy or the gear for that matter been changed at any stage ????

I konw that with some dizzys you can put the gear on the wrong way . IE it will go on sweet but will be out of ailgnment...... Ie will be a few deg out. I installed 180 deg the other way it will be sweet. ?????/?


Lol long shot i know

[Cuzzo]

Is it out 1 more tooth? Have you possibly set it back two teeth and not just one.?

[slide86]

sounds like its still retarded heaps. slow revving and lacking power......symptoms sound like retarded timing.

when you checked the cam and crank timimg did you check to see if the dizzy was pointing at no 1 cyl at the same time. that would be the first thing to do.

get the engine to no 1 TDC and the dizzy in the right place. once you have done this, at least you know that the mechanical side of things is good. maybe then you can point towards an electrical fault.

[toddw]

I would have expected it to perform better at 20 BTDC. In my train of thought it may ping but would perform better than at 10 BTDC. I know it this doesn't help with your problem though. At hhe end of the dizy there is a small line that you line up with a dot on the gear. when they are line up you should be able to put the dizy in and you are in the correct spot with only minor adjustment required with a timing light.

[Pure_In_Sanity]

I'd be looking at the dizzy gear like mr 4agte said. Someone may have done the internal dizzy seal and put the gear back on 180deg to what it came off.

[DeftAnesthetik]

i hope this is just a stupid question but have you checked compression accross the cylindersyet?

[spoon]

I have exactly the same problem as gavatron - spent ages last night trying to sort it out to no avail.

we checked timing belt to crank pulley to cam positions multiple times - made sure engine was at tdc (removed spark plug - checked with screwdriver down the hole), made sure cams were lined up with timing marks, removed and reinstalled distributer a few times making sure it was only 1 tooth apart between installs, but still had the same problem.
we couldnt get timing (measured with a timing light of course!) to read between say 7 - 20 degrees, only figures either side.

does anyone have the solution to this?! The distributer was purchased seperately to this engine, so im hazarding a guess its not the right one... was told it was from a 4age mr2, engine is ae86 rwd 4age with jdm loom and computer - plug on the dizzy goes into loom so im a little doubtful...

btw, am i missing something or is there no diagnostic box on these looms for shorting the terminals?

thanks

[wiso]

more this is to spoon, are you 100% sure you put the dizzy in with all matched markes lined up? usually what I do there is a dot on the dizzy gear and a dimple on the housing, line these up. the marking sure these are aligned till it goes into the head where the dizzy face meets the head face there is 2 dots on the dizzy. you line the fatherest clockwise dot (from the rear) with the corner point on the head the dizzy goes against. if you first rotated crank to TDC and checked the cam matchmarks lined up this should be spot on 10 degrees.

from my experience if you think the dizzy is out 1 tooth and pull it out rotate it a little then push back in I have found it never works. matching all the marks is the only way.

Also don't do something stupid like me last time drove me mad trying to set the timing I was lining the marks over and over and couldn't work it out. it was about 5degrees out because I left a vac line off seemed to retard the timing when bridged, but advance like a bitch when unbridged with a vac leak. took me ages to work it out. doi

[pandaah]

id be doing the above resetting with the dot on the gear and line on the housing instead of "going back and forward one tooth"... then it that definetly doesnt work, spin the gear around like the guys above have said "or try a second hand dizzy if available" .. then reset the timing again..

[andrew_mx83]

definately sounds like something is up in the dizzy if the timing is all spot on and the belt is tight.


ive rebuilt a few 7m dizzy's now and it sounds as though either the trigger wheel is misaligned with the reluctor pickup or the drive gear is misaligned with the shaft.

there also seem to be a whole bunch of different 4age distibutors (i had a bitch of a time matching a cap & button for one recently) so it is possible the pickups are offset differently in some types. dont know enough about 4ag's to confirm this one.


whatever the case, if you take rotor button off you will expose the trigger wheel. you need to rotate it on the shaft (very slightly) however it is a press fit on so a little difficult.
best bet is with the dizzy installed in the engine or in a vice, stick a couple of pins/bolts in the holes in the wheel and use a long screwdriver to twist it slightly. match mark its original position before you start in case you fuck it up. reassemble all properly with the dots etc and check the range of timing is about normal.

[andrew_mx83]

like so:

[oldeskewltoy]

here is what I recommend... remove the exhaust side cam cover, this will allow you to actually see the distributor engage the camshaft... and if done incorrectly, it will allow you to mark the gears and let you see the change.

If after verifing that you have moved it only one tooth and the problem still persists, then I'd look inside the distributor and check the pick-ups inside to see if they are aligned correctly. To do this, make sure the engine is @ TDC and look at the pick up to see its location. The exposed exhaust cam will allow you to move the teeth one at a time and so check all your pick up points.