engine wont start

[evil86]

hey guys, i have a situation on my hands at the moment, i just drop a jdm 4age big port in my 86. it has all the jdm wiring including dash wiring. so whole front end has jdm loom from dash to headlights.

when i try to start it, it cranks but doesnt start. im running jdm tank with no intank pump but running an external pump. motor has got fuel going to the rail but the return line has very little coming out. motors also got spark and have tried to do top dead centre many times... car has also got alot of compression...

can someone help em out..?!?! im to the stage where i've got too much white hairs:)

[gumbie]

try push starting it and see if it fires up then that should eliminate a few things.

[evil86]

will try that tomorrow when the rain stops at my place

[adam]

So timing is all correct?

When you pull the spark plugs out straight after cranking the motor, does it smell strong of fuel?

[evil86]

i dont quiet get what your saying.. i dont think the timing is right, so its hard to clutch start.

[adam]

From what you've said, you've got fuel, spark and compression. That's all that's needed for a motor to run. Only other thing I can think of that would stop it from starting is the ignition timing. And going from your first post you seem to be unsure if the timing is set correctly.

When your motor is set to top dead center, do the cam gear dots line up with the covers? Is the dizzy dots on the shaft lines up?

[evil86]

yeah, everything lines up, i think the motor been flooded because there was heaps of petrol in the chambers when i took out the plug eariler

[lloydious86]

remove the dizzy cap and plug from cylinder one, use a long screwdriver place it ontop of the piston, rotate the engine and watch for the rotor to pass over the sensor when it does this the screwdrive should rise to the top (TDC), that should indicate wether your timing is close enough to correct for it to start. When youve pulled the plug out the motor is getting fuel and if you can confirm its got spark i have a feeling its go to be timing. If it was crank angle sensor id feel it wouldnt be sparking at all considering this runs off the dizzy wich provides spark but which you have, usually motors will start without 02 sensor,afm or tps faulting but couldnt hurt to break out a multimeter check power supply to these and resistance on all 3

[evil86]

um... yeah i've tried TDC, there is pressure in the fuel in going to the fuel rail, theres also fuel in the chambers.

i dont know how to use a multi meter...

so if i get timing right, would clutch starting start the car?


ps. when i check the spark, its kinda sparking slow, could that be the problem?

[350hp4agte]

you will have to get rid of the fuel in chanbers but be carefull doing so either leave the plugs out for a day or so or take the plugs out and crank the motor bu diconnect the coil b4 ya do that

and how slow is it sparking

[evil86]

how slow? how do i describe that... sparks every second ?

[Matt-AE86]

If like you said its a JDM loom, and its only the Engine loom, not the entire car loom aswell, you may be missing a relay for the injectors. This is what you need to do to check.

Go to your ECU. Check that the BF pinout on the 10pin plug to the LEFT.

Check that this has 12v when the key is turned to ON (Ign ON). If it doesn't, temporarly add a wire from BF to B+. Try to start the car again and see what happens.

Ecu pinouts below.
http://club4ag.com/faq_and_tech_pages/Tech%20Photos/Techno%20Pro/ECU_Japan_AE86_1984-85.jpg

Also, I find the best way to check if your spark is good is spray start your bastard into the throttle and then try and start it, if your timing is out it could back fire, if it isn't it will run breifly.

Try these 2 things and let us know.

[Rice86]

hahah, yeah we experienced back fire from the throttle body at one stage, we did the timing again and again but didnt crank it to long, didnt want hands and head burnt

im sure its the timing or something small...just not to sure, but even if the timing is off a bit, it will kick over and run on its own...it doesnt even do that

i did the timing on his car, and from my experince, i can get the motor to just run even if it was like shit...so with that in mind, its most likly a ecu wiring issue?...

i'll play with the timing again if he already hasnt got it running by then

[Matt-AE86]

not likely. but its something to check when it wont run or runs for abit. but sounds like your timing is out. consult the 4age manual to learn how to set the timing correctly.

[KE70]

Hey guys, i have a simular/same problem with my car.
i tried the above and it runs on start ya bastard, and also has power on BF so now im back to square 1 for the 20th time.

Any help will be appreciated.

[evil86]

awww k... tried cranking the bastard today, tried different timing and it cranks well at 10, then suddenly the positive terminal starterd to smoke and turn off motor. now the wires to the starter motor is hot and now when i try to connect the battery, it would spark alot. any ideas

[Simon-KE70]

bad ground more then likely. were the calmos on the terminals tight or just pressed on? if its a poor fit or if there is corrosion there you'll only get a small contact area, the starter draws a lot of current thro this and gets bloody hot then.

either that or bad/poor earth.