pardesi

So here is my dilemma, I changed the timing belt in my GS400. All timing marks I placed back matching the marking on the belt as well. I don’t think the timing is off.

I did however forget to take the battery terminal off so while tightening one of the pulleys my brother thought he saw a spark and I didn’t notice anything. So putting everything back and then checking the main fuse box next to the battery. Found out that the alternator fuse blew (120A). I replaced the fuse and also checked around if any of the wires were cut but no such thing. All wires are connected in that area by the alternator.

Now the car won’t start, the engine is cranking very slow but won’t turn over. I have the battery on a charger so the battery is fully charge.

Anyone has any idea what could be wrong or how i could further diagnose this issue. Thanks for your help!

pardesi

Well some additional updates... my brother has a GS400 as well so i swapped some relay such as starter, Eng Main, and EFI. Which made the car crank faster but still didn't start. Same relays in his car worked just fine.

So i'm thinking it's something electrical where a spark may not be triggering.

salimshah

Did you turn any shaft after the t belt was removed?
Merely matching the maks is not enough as TDC happen on compression and exhaust stroke.

Salim

Bill_GS3

Sounds to me the timing is off.

GWELEX

So true, he could be 180 degrees out of time. Ensuring the crank pulley was lined up on TDC of the correct piston is critical. One other thought came to mind, the ECU. Have you disconnected your battery for 15-20 minutes so it can reset?

pardesi

Yes i had to turn the left crank pulley. Once i took the belt off the pulley moved slightly, but the way i turned it was to just move it back. Not take a full circle. I can double check that, but how. If i open the first firing plug the piston is all the way up when left crank pulley is matched.

Thanks!

pardesi

I did have the battery off for 20 minutes, so the ECU should be reset.

I guess i need to figure out how i can double check my timing. I can rotate the engine just fine.

Thanks for the reply!

salimshah

As long as you brought it back (net change of zero) you should be fine. If you spun any full circle then you you have to figure out compression stroke. Compression stroke is determined by all valves closed (you can use compressed air at the plug to figure it out, or by observing the valves). For timing, the spark should be produced at that time as well.

Dble check the markers are still aligned after the tensioner picked up the slack. Then bring out the timing gun.

Salim

pardesi

So I took a look at the valves. In the attached pic i show the R crank shaft set at the timing mark, next to it is the L one and below is the center one marked set at 0.

I took the left valve cover off and in the picture below you see the position of the valves. While turning the center pulley leaving the belt on at this time, i notice when i do one full rotation of the L cam pulley the valves end up in the same position. So if i was to take the belt off, and then rotate the L cam pulley only one full rotation it will end up in the same position. Does that make a difference if i do that since the position of the valves will be the same.

Just some more info, i guess i need to better understand how the valves are functioning. May have to go find the manual or if someone has link to the valve info on a GS400 that be great.

darrylg33

When your turning the engine by hand you should hear the compressing, and creating some resistance when your spinning the crank, as the pistons reach the top before the exhaust side opens. No pressure, or if it is free spinning with no problem, your probably out of timing, take everything off and start from scratch. Don't have the pdf for a V8 or I would have atatched it...sorry...D

Bill_GS3

PM me and remind me to pull up the WSM on this tomorrow. I can only access it while I'm at work. Toyota/Lexus security thing.

pardesi

I feel some what of a compression, my younger brother has the same GS400. I'll see tomorrow how his feel when manualy spinning the engine. Otherwise like u said start again from scratch.



Thnx Bill.. PM Sent!

salimshah

2turns of the crank shaft "C" match 1 cycle of valve train connected thru R and L.

Q: Your R pully seems to match the marking on black material, but I see the stamp on the back plate is off ny 2 notches. Since I have not replaced T belt on GS, so I cant say for certain which are the right marks.

Q. Since you had fire-works, are you are getting a spark.



Salim

pardesi

I'll double check but i belive where i have it are the marks (l), the T symbol represents somthing else.


No that is my other concern, i don't think i'm getting a spark at all but need a better way of testing that. If i put an electric tester next to it and try starting it doesn't beep. If i do the same test on a working GS400 it beeps but by then the car has started.

Lets say if i'm not getting a spark, could that be becasue the timing is off or is it an electrical issue.

salimshah

Timing is a term used for spark at a certain time [speced with reference to TDC of compression stroke in degrees]

Timing being off, means your spark is not at the right time.

No spark (irrespective of timing) is an electrical issue. Check distributor as a start point.

Salim