Jump to content
HybridZ

My theory on my problem....


Guest Zpeed

Recommended Posts

Hi guys, well my Z is still sputtering, i thought it was good once i changed ova the carbs, but it is still there.. and i believe i have realised the problem but not completly sure, the Z shops are closed here in melbourne, its sunday...

 

symptoms: when i rev it up to around 2500 3000 it has a really bad response, i get it up to 3000 2 secs later it starts pushing, and it misses horribly, and somtimes the carbs backfire... i have crappy acceleration due to this, and feels really sloppy...

 

My theory: I believe it may be the distributer shaft.... the timing when it is idling is perfect, what the haynes book says, 7degree@550rpm or something like that, 10degree@650rpm, that is perfect.. the points in the distriburter are good, i've changed my leads, new sparks, new fuel filter, and also i rebuilt my engine just ova a week ago, and i don't full remember if it was doing this when the engine was bad,

 

that is my theory the dizzy shaft is bad and causes it to miss and have bad response... the other reason i think this is becuase i can rev it up there slowly and it is okey, but i can't mildly push, i'm driving like my grandma and so many other people are just looking at my datsun thinking its a POS which it an't....

 

does anyone else have any suggestions or thoerys, or does anyone support my theory..

 

i'm not sooo mechanically imbond, but i've learnt so much from my Z, and i've checked everything, cept for the fuel pump but that seems to be working prefectly...

 

i used a clear pipe to the carbs to see if i was getting fuel in...

and its not the carbs because i did change my carbs ova from the SU's to the flat tops and i have the same problem...

Link to comment
Share on other sites

Sounds like some sort of timing issue I think. Double check your wires connected to the distributor, and that your firing order is right, and the wires are going in the right direction. Are you sure that your cam timing is right, and not 1 tooth off? That would give you similar symptoms.

 

Also check to see all your spark plus wires are hooked up, and the plugs are gapped well. Good luck.

Link to comment
Share on other sites

I have been fighting a similiar battle. I've had a miss(rough idle, surging, and sputters) for a long time now. After changing to MSD and changing out the carbs for ZTherapy's, changing the dist. for a known good one, checking timing over and over again. Double and tripple checking cam timing, oil pump/dist shaft location, I have come to the same conclusion. Play in the dist. to crank connection. I plan to replace this shaft to see if it helps or possibly go with a crank trigger. I really don't want to spend that much on this L series, because I'll be going V8, but I want to keep adding up kills before it goes under the knife.

Link to comment
Share on other sites

well my friend who has had a similiar problem to me, said that he replaced his distributer and it fixed the problem, i should try what scottieMIX said about jiggling it to see,

 

i havn't adjusted my valve clearances since the rebuild which i will do tommorrow,

 

I don't want to rush into buying anything straght away, due to my budget being really low, the firing order is what it says in the haynes book... and it moves anti clockwise..

 

 

mmm... i'll go talk to some Z guys in melbourne tommorrow, i went today but he was closed....

 

I'll keep in touch of what the problem is

Link to comment
Share on other sites

Guest Anonymous

I saw you posting on your, you have the flat-tops? I would say rebuild your 240 carbs, it's easy most of the time you can just change the needle and nozzle and clean up the flaot bowl with carb cleaner. As for the dist. rebuild, why? just buy a good used 280zx dist.(comes with ignition module) and base. Then you can say bye bye to points and it all bolts in. The wireing is easy one power in and one signal out.

Link to comment
Share on other sites

well billyZ thats exactly what i am planning on doing, rebuilding my 240z carbs, but i'm only going to get new needlesand a nozzle... and with the carb cleaner clean everything that i can get to...

 

and the problem with the distributer is that they are hard to find a 280zx one... and i can look thou a place that have S&*T loads of distributers but i don't know how a 280zx one looks like and either do they....

 

but i'm trying to find a wrecked 280zx here and get the dizzy from it... i believe that it will be worth it...

 

i got a price of AU$25 each needle and AU$85 for the nozzles.... is that worth it...

 

should i get them inspected first...

Link to comment
Share on other sites

i've just found a 280zx distributer at a wreckers, i'll be going there tommorrow...

 

how can i tell if a dizzy is stuffed or not..

 

also the place has a LSD r200 rear that i would like to look at also... haha

Link to comment
Share on other sites

Guest Anonymous

The 280zx dist. has a black box on it which is the ignition module. You will need the part that the 280zx dist bolts to from a 280zx. If you are strapped for cash just buy the neddles. If you have never rebuilt an su carb look around some web sites for info and or get a Haynes manual.

Real quick tips, take dome off, remove piston with needle. clean, remove needle install new one. thick part of needle goes flaush with base of piston. clean butterfly and inside of carb. and put all back together. If you have a float problem remove float bowl top, clean, make sure float floats. Set float so it is level with base upside down.

Billy

Link to comment
Share on other sites

yer i've taken my Carbs apart before... i'll just get some needles first and see how it runs then...

 

the dizzy that i said i found, got sold today around 20minutes before i got there.. he said he thought that the guy who bought it was me... damnnn

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...