Tiny70

I just did a complete engine rebuild. after re connecting all the cables and hoses we did not have any power to the coil, I purchased and installed a new CPS and now i have spark but only back fire and engine will not start. I have double checked the timing gears, distributor, all was in line at TDC on #1 cylinder with #1 valves closed. I am at a loss, any suggestions?

buccofan10

im in the exact same boat. i have reset the distributor about 6 times and still wont start. will get a backfire every now and then, and this last time it almost sounds like its losing power after a few cranks.

CCKen

Checking distributor timing.


Check to see if the distributor is timed properly by removing the distributor cap, rotor, and cam sensor, then reinstalling the rotor.


Turn the crankshaft damper clockwise to align the zero (O) mark on the timing chain cover with the index mark on the damper. If you go too far, back the damper off counterclockwise then slowly move it clockwise to align the timing marks.


Look at the distributor rotor. It should be just past the #1 spark plug wire cap terminal position. If it's pointing at the #6 terminal, turn the damp 360 degrees to the alignment zero mark.


Insert a 3/16" pin punch or drill bit down thru the 4.0 hole in the distributor plastic ring down thru the alignment hole in the base of the distributor. If it freely goes thru the two holes it's in time. If not, the distributor is out of time. If the distributor is out of time, reinstall it with the pin punch installed.


See pics.


Alignment timing marks:



.
4.0 alignment mark in the distributor (with pin punch installed):



.
Installed distributor shown with pin punch installed. Note position of the rotor at #1. Modified cap installed



.
Spark plug wires installation on the cap. Important:



.

CCKen

Be aware that if you have installed a replacement distributor and it will not time in no matter what you try (with pin punch installed), the replacement distributor may be for a 4 cylinder engine. The distributor bases are the same except that the distributor drive gear splines on the 4 cylinder distributor are aligned differently than the 6 cylinder engine drive gear.


6 cylinder drive gear:


With a pin punch installed, look at the position of the drive gear roll pin and the entrance to the helical spline on the drive gear. Proper installation shown.





Detail of the spline entrance on one side of the gear.





And roll pin alignment with the spline on the other side of the gear.





The 4 cylinder engine distributor drive gear splines are not aligned like these 6 cylinder gear splines.

buccofan10

is it possible that the crankshaft pulley was replaced previously by someone and the TDC notch is not lined up correctly with the "0" mark? thus meaning it being 1/4 or half a turn off one way or another? and if so, how should i go about finding TDC?

CCKen

The crankshaft vibration damper is keyed to the crankshaft and can only go on one way.


To find Top Dead Center - COMPRESSION stroke, remove the #1 spark plug and, while having a helper hold their finger over the spark plug hole, rotate the damper clockwise until air pressure is felt from the piston traveling up, then stop.


Recommend outlining the damper timing slot using paint, chalk, or grease pencil (like in my pic above) for better viewing.


Also recommend removing the radiator electric fan so you can get direct view of the timing marks


Now, continue rotating the damper clockwise slowly until the timing marks align at zero (O). If you shoot past the timing marks back up the damper around 90 degrees and start over again. When getting near alignment bump the hinge handle or ratchet handle you are using to turn the damper with the palm of your hand in order to get exact movement.


After reaching the Zero degree marks remove the distributor cap and see where the rotor is pointing. It should be pointing just past the #1 plug wire post (see my pic above). Then remove the rotor and cam sensor, then see if a 3/16" pin punch or drill bit will drop through the alignment holes on the distributor (see my pics and instructions above). If so, the distributor is timed correctly.

JRPCHAMELEON

This might not be as help full as previous comments but, you say you have fuel and spark but do you have compression?

97grand4.0

"we did not have any power to the coil, I purchased and installed a new CPS and now i have spark"
Do you have power to the coil? Or more correctly stated, do you have voltage at the coil with the key on?

Tiny70

I have done all the above, triple checked timing, replaces the crank position sensor, MAP sensor, and cleaned the IAC sensor, it is getting better now with some signs of trying to start. smells like the fuel is rich and the plugs are wet, checked the injectors and all are spraying. could it be the TPS?