problem: engine won't fire

[l1ttle_d3vil]

me again

yes, i've got spark. now my problem is the engine won't start, it'll try to fire at random times and hardly at all.
im pretty sure the fuel is getting through the rail cos i think i can hear it running through the return line, seems like theres something wrong with my injectors.
i took the fuelrail/injectors out of the injector holes and turned the fuel pump on and nothing came through the injectors (even though fuel was going through the rail). when i turned the engine over some fuel shot out of the injectors for a split second then stopped...is this how they are supposed to be? or should it be a constant flow?
every time i turned the key it would only do this once, it wouldn't keep squirting every time the engine turned over or anything.

does this mean ive got a problem with the injectors? or are they flowing as they should be? is this just something as simple as getting the timing exactly right? i can't find the timing marks or anything but have had someone else set the timing to what they say is right, or atleast quite close.

anyone got any idea as to what could be wrong? i don't even know who to ask about it - an auto electrician or mechanic!

cheers

[ee904age]

How is the cam timing? Try checking the fault codes, itll take a bit of mucking round since you dont have a check engine light but it can be done with the help of an LED.

[l1ttle_d3vil]

the cam timing has been set...
how can I check the fault codes with an LED then? is it easily explained?

and also what is the firing order, on the distributor cap it has got 1342, is this correct? and is #1 the plug nearest the cambelt with #4 being closest to the gearbox? or the other way around?

and where exactly are the timing marks located on the bluetop? i could just be looking in the wrong place for them...

[ee904age]

Yeah the firing order is the same as almost every japanese 4 cyl on the planet 1342.

I'll email you on how to use the LED.

Number 1 cyl is closest to the cam cover, and the timing mark may be very hard to see, can you see the degree markings on the bottom plastic cover by the crank pulley? if so then turn the crank by hand looking for a tiny notch on the inner rim. When you have found it mark it with twink or something and you'll be right. (this is assuming the pulley hasnt been hit with a hammer or something in which case the will be a few notches!!!)

[l1ttle_d3vil]

cheers, that just confirms that i HAVE got the plugs in the right order and all that.

i'll have another look for the degree markings...if the injectors squirted for that little bit each time i turned the engine over, is it likely to be something wrong with my wiring? (not getting the proper signal or something) or is it more likely that they wouldn't work at all if that was the case?

and would some injector clean be of any use?

[l1ttle_d3vil]

just got the bottom cam cover and yes the timing marks are on there...thats why i couldn't find them - i dont have the covers on my engine at the moment

there is a little "knob" thingy up the top of the hole the crank pulley goes through, is this anything? and i think the notch on the pulley you're talking about, that was used for the cam timing. is that to do with the distributor timing instead?

im not 100% sure whether the timing was done right from the start, so the problem could be anywhere to do with the timing i guess. should i post up some pics with what notches we lined up with what, to confirm whether we set the timing right or not?

cheers
-matt

[l1ttle_d3vil]

ok i got my spark plugs in the right order etc. i got spark. i know the injectors aren't blocked, but not sure whether they are flowing the fuel through as they should be. seems they might only be squirting the fuel thru once then stopping, rather than squirting again and again.

i realised that i didnt have the STA pin from the ECU connected to the ignition though so have wired that up, seems to fire a bit more regularly now but not "properly" if that makes sense.
i ended up with a pretty big backfire coming out of the inlet manifold tonight, would this mean the timing is out? (ive been told it could be a reason for the backfire) or are there heaps of other reasons which could contribute to it?

probably a bit hard to understand exactly whats happening by describing it on the net so i'll be trying to get a mechanic to look at it in the next few days. any help0 in the mean time would be much appreciated though.

[lazarus]

One thing if you do have all your timeing etc right check the battery or starter motor because in most Fuel injected engines the injectors wont start working untill the engine is up to proper cranking speed, if its not quiet there no injectores opening:D


Its something simple that alot of people dont think about

[l1ttle_d3vil]

ive got the battery connected up to a 12v jumpstart pack, so its turning over no problem at all.

what about if ive got the injector plugs going to the wrong injectors? is there any way to tell if i have or not other than tracing all the wires back to the ECU?

edit - ive tried the injectors in every different sequence possible and still not much luck. only difference is it seems like was "trying" to fire better with the injectors in certain sequences than others, also ended up with some big backfires and flames coming out the inlet manifold.

[sergei]

have u checked ur distributor, if its timing is proper?

[ChaosAD]

has the seal on the dizzy been replaced? cos I had the same problem. Found out when they replaced the seal they put the sproket back on wrong and although the timing light shows 10 degrees the engine was sparking on the wrong stroke (crank turns twice for every one turn of the cam).
As for the injectors, the ecu pairs them into two groups. the ecu switches the ground wires and they are the two black wires on the 10 pin plug on the ecu (if you have an ae82 loom)

[matt dunn]

As for the injectors, the ecu pairs them into two groups. the ecu switches the ground wires and they are the two black wires on the 10 pin plug on the ecu (if you have an ae82 loom)

.

Yes but inside the ECU they are still all joined together so they all fire at once.

[ee904age]

I would check that the dizzy is set right first, making sure is pointing and no. 1 cyl etc. As for the injectors, I dont think its a problem yet, once you get it firing regularly on cranking and if it still wont start, look into it then.

[l1ttle_d3vil]

Yes but inside the ECU they are still all joined together so they all fire at once.

im not sure if thats right, on an ae92 pinout it says one of the pins on the ECU controls injectors #1 and #3 and another pin controls #2 and #4 or something like that. the ECU code for these pins are #10 and #20.

on the pinout for my ECU (its the 1984/85 diagram here - http://www.club4ag.com/faq%20and%20tech ... 04A-GE.htm) there are still the pins with the code #10 and #20 for the injectors, except it says they are for all four injectors. so not sure if my injectors are controlled two at a time, or all four at a time.

does anyone know of a website which shows how to set the valve timing? this couldve been done wrong, otherwise i'll post some pics up showing how it was done.

also, the only relay ive got is the EFI main relay. is this all I need or should i have more? and am i supposed to have an injector fuse on the ae86 loom? i know there is an injector fuse on another loom i have (redtop or something i think) but not sure if a bluetop loom should have a fuse aswell.

[l1ttle_d3vil]

this is how the valve timing was set. the indents on the teeth were lined up with the nobbly things in the green squares. i couldnt see any mark on the crankshaft pulley, but my dad says TDC is generally with the keyway on the pulley at the very top so we turned that to the top while holding a finger over the #1 sparkplug hole to make sure it was TDC (which it was). im just not too sure what the other nobby things (below and to the left of the green squares) are - they're nothing to do with the timing is it?



we have also taken the sparkplug out and and watched the spark with a finger over the hole to check the compression, and the timing seems about right for both (as in its sparking at pretty much exactly the right time).

so is this how the timing is supposed to be set? all i get when i turn the engine over is muffled backfires, then one f**ken big one out the inlet manifold often accompanied with a pretty decent flame

[matt dunn]

im not sure if thats right, on an ae92 pinout it says one of the pins on the ECU controls injectors #1 and #3 and another pin controls #2 and #4 or something like that. the ECU code for these pins are #10 and #20.

Yes but they are joined INSIDE the ECU. Your diagram will not show you that.

Your top marks on your cam timing are correct, but I am not sure that the way you describe the crank is correct.
There is a mark at the back of the bottom cam wheel and they line up against a makr on the oil pump cover.

Matt

[l1ttle_d3vil]

i had another look on the bottom crank pulley tonight and eventually found a mark on it, which just so happened to be perfectly lined up with a nobbly thing on the oil pump cover at the same time the top gears (pictured above) were lined up at the appropriate place. so i take it the valve timing is definitely all OK.

Doesn't seem to be any problem with the spark timing at all - its sparking on the compression stroke at TDC.

im still just getting muffled backfires for about 6 seconds while turning the engine over, then a huge bang and flame out the inlet manifold. seems like its getting fuel in there one way or another for it to backfire like this right? my brother (an automotive mechanic) suggested its just not getting enough fuel.
any reasons why this would be? the injectors don't seem to be blocked at all. he says the injectors are triggered by an earthing signal from the ECU - does it make any difference whether the ecu itself is mounted somewhere where it can earth or not? (same principle as the coil - it wouldn't fire unless the bracket is bolted/clamped to the body)

EDIT - just tested the injector plugs tonight for power, with the ignition on there is 12V coming out of both pins on the plugs. should it be like this? then when i switch the ignition off there is still 12v running through both pins. is this how it should be?

EDIT #2 - just had a thought. to start with i though it could just be the injectors are blocked so i took them out of the injector holes and set them up on the fuel rail and turned everything on. on the first "turn" of the engine the fuel squirted out then stopped [even though i kept the engine turning over]. i had to turn the key off then turn i tback on and once agin on the first crank of the engine the injectors would fire then stop.
now what are the 2 wires in the injectors for? one for a start signal and another for a stop signal? if thats the case, and seeing as there is 12v going to BOTH pins with the ignition on (which i dont think is right?), is it possible that as soon as the injectors turn on they get the "turn off" signal and stop squirting after that.
whats the likelyhood of this?

[matt dunn]

im still just getting muffled backfires for about 6 seconds while turning the engine over, then a huge bang and flame out the inlet manifold. does it make any difference whether the ecu itself is mounted somewhere where it can earth or not? (same principle as the coil - it wouldn't fire unless the bracket is bolted/clamped to the body)

Ok, on the subject of earths, Make sure the two brown earth wires are connected on the centre of the inlet manifold, it uses one of the bolts that hold the wiring loom in place from memory.

You will get power at both sides of the injector as the power will flow through the injector and out the other side, and unless you unplug all four injectors you will still get power on both wires.

If you think it is not getting enough fuel, buy a can of CRC engine start and spray it in while someone cranks it over.
If it tries to run, it is a fuel problem.

If it spits flames out the intake at you ( like i think it will,) it will be a ignition timming problem.

Matt

[ChaosAD]

My car did exactly the same as what you have described.
With a multimeter check that the injectors are getting 12v when the key is on (ecu switches the ground).
It could be that the only fuel the motor is getting is through the cold start injector (which is mounted on the plenum chamber).
If there isnt 12v then check the 'inj' fuse mounted on the airbox.
Also, there should be a whole lot of solenoids mounted on the ecu end of the engine loom.

Check EVERY plug

[Lloyd]

Are there any other marks on the cam pulleys? The gears on the silvertop I pulled to bits had 2 marks on the pulleys, one of each lined up as you've put and the other 2 lined up with themselves where the pulleys are closest to each other, much like Subaru timing marks do.