1990 Nissan 180sx ca18det timing

[JoNo180sx]

ive been having some trouble trying to get the timing right on my ca18det, everything is stock except for pod and bov and also 3" exhaust, running around 12 psi according to my boost gauge when it was running fine, i have checked for boost leaks vac leaks, everything is fine except for my timing. i know about getting C# 1 tdc and lining up the marks on the cam gears with the marks on the block with the ones on the belt. but i have tried that 3 times already and car is still not running right, at low rev it shakes and chugs but over 2500 rpm engine seems to run like it should but no where near 12 psi as i was getting before... and i dont understand why ??

SOMEONE HELP !!!!!!!!!!!!!!

[float_6969]

Did you replace the timing belt?

I have found that the use of a couple of pair of small vice grips works wonders in keeping the belt in place on the cams. I usually start with the crank pulley and get that lined up. Then I do the intake cam. Once I get that right, I put one of my small vice grips on it, and move to the exhaust cam. Then another pair on the exhaust cam and make sure everything is still lined up, then release the tensioner and tighten it up. Then I'll turn the motor over a couple of times by hand (using a long ratchet) and then make sure it all still lines up.

[JoNo180sx]

yeah i have brought a brand new belt,

i made sure everything was lined up like it should have been span the motor a couple of times but then the belt marks didnt line up but all the other marks where perfect should the belt marks always line up ??? im not sure what im doing wrong but its getting annoying ha

also had the timing light on the bottom pully and it was way off from the six marks ?? so i must have buggered up getting tdc ?? corret ??

[JoNo180sx]

could have the belt slipped a tooth ?? i didnt know tight to have the tensioner so i left it loose ??
how tight should i have it ??

[boost_boy]

could have the belt slipped a tooth ?? i didnt know tight to have the tensioner so i left it loose ??
how tight should i have it ??

You left it loose? Do you have money to throw away because when it slips enough, your pistons will kiss your valves and it will cost you time and money.

[float_6969]

The marks on the belt won't line up once you turn it, but all of the other marks will line up again. Belt tension should be covered in the FSM. I don't remember the exact amount of pressure off the top of my head, but I'm pretty sure it's in there. Also, boost_boy is right. This is an interference motor and you don't want that belt to slip too much.

Just keep at it. It's not hard to do right, it's just really easy to do wrong. Your timing light showing the marks being way off tell me you have something wrong. You know the dot on the crank pully lines up with the notch in the oil pump, right?

[JoNo180sx]

i didnnt leave it loose loose i let the tensioner do its job and went a little tighter than the tensioner, toke it all apart once again everything still lined up fine, so took the belt of and started all again, got it running alot better but ive given up now and ive takin it to the shop. hopefully i havnt done any damage.

thanks for your help tho

[JoNo180sx]

Picked up my car from the shop.. I've bent a valve in cylinder one.. brought some valves off ebay to put in will be grinding them when i put them in. toke me 7 hours to get the head ready to be taking off realising I don't have a 10mm alan key bit for a socket set, went and brought one today and will finally get to take the head off tomro to see the damage. Should I still get the head shaved ? I need to replace the head bolts don't I ?

[float_6969]

That sucks about the bent valve. I would HIGHLY recommend taking the head to a shop and having a valve job done. Chances are pretty good that there is some damage to the seat on the bent valve, and it's always a good idea to have the new valve and it's corresponding seat re-cut so that they match up perfectly. You would also be amazed what a valve job will do for power on an old motor.

As for the head being shaved, no. Just tell the head shop that you just need it resurfaced and they'll only take a VERY small amount off to just clean it up so it will hold a seal.

Head bolts DO NOT need replaced. They are not a TTY bolt, and hold plenty of power. They're also MUCH easier to remove/install than the ARP's. Honestly, if I hadn't pitched the stock head bolts, I would take out my ARP's and put them back in. Plenty of people have made lots of power on the stock bolts with no issues.

[JoNo180sx]

ive got the valves done, head done ready to put it back together just waiting on my head gasket to arrive, cleaning the block when that arrives, i was thinking about doing a compression test to make sure the seal is good before i put it all back together ?
putting it back together on friday hopefully,
any advise with putting it back together ??
il let you know how i go.
cheers for the help

[float_6969]

You can't do a compression test without a starter hooked up to spin the flywheel. Did you have the bottom end rebuilt? If so, there is no point in doing a compression test until the rings are seated.

As for advice on putting it back together, just follow the FSM.

Happy to help!

[JoNo180sx]

na only top rebuild,

so good news, put the head back on toke me 2 days ha but finally did it, started the car idle was perfect waited for it to warm up and toke it for a spin.

i have a bogging down issue over half throttle , i still have plenty of boost, the power is there just bogging down and hesitating, idle is fine not coughing or anything. not sure if its a timming issue because i think i checked it more than 10 times and im 90 % sure i have it right. but this weekend will be taking the front off to double check.

do you have any other advice on things to check if its not a timing problem ?

cheers

[float_6969]

any codes?

[JoNo180sx]

just checked it then ecu is normal.

[float_6969]

Sounds like it may be ignition related. Have you checked out the coils and ignition amplifier?

[JoNo180sx]

Checked all that mate seemed to be fine, so toke it apart once more got 3 mates to help line up the belt and the gears put it all back together. Started her up toke her for a spin and she is running perfect
Went for a drive into town and mr po po pulled me over and got me for excessive noise so now I gotta get a dam epa test done... just my luck..

[float_6969]

That sucks about the ticket, but I'm glad to hear it was just cam timing.

[JoNo180sx]

Yeah I know alwell..
Anyways I seem to have another problem it will randomly bog down sometimes for no reason take my foot of the gas and put it back on and it's gone. Not sure what's going on but on the intake rocket cover there a breather hose/ vac hose and it has a split in it would that cause it( its the hose that goes to the block under the knock sensor) ? Ill be fixing it later today must have done it when I was putting it back together.
Cheers