240z still not starting

[LeonV]

Yeah. Ive got 5-20 weight in it. Couldnt find a better option locally. It seems like it doesnt really kick in soon enough, like the lowest bit isnt dampened, causing a lean mix. Im pretty sure I got plenty in there, they are pretty hard to move. I really am wondering about vaccuum leaks but all thats changed is the carbs, and all the bolts are tight, I checked that yesterday. Being that nothing changed but cleaning the carbs, changing the starter motor, and plugs. I dont see how a vaccuum leak wouldve developed, but I'll look for one

The damper fluid has some control over throttle transitions. If you're going lean on transition, the fluid is too light. Vice-versa for too rich.

That's assuming everything else is working properly. Before really tuning the carbs, you have to make sure your ignition is spot on, your valves are properly adjusted, compression is relatively even across cylinders, and NO vacuum leaks.

Vac leaks can easily be checked by spraying starting fluid (or other volatile substances) in suspect areas. If idle quality noticeably changes when you spray a certain area, then there is a vac leak there. Usual disclaimer: don't set yourself on fire and be careful about spraying chemicals on paint.

[ninjazombiemaster]

Interesting day. I rechecked everything, and found out that dispite having checked it a dozen times, the problem was indeed spark plug cable 2 & 3 were switched. Runs like a bat out of hell now. Also, the freezing rain ruined my clear coat. A buddy of mine will give her a full body repaint for around $1500. Super bummed about that, but it needed a touch up anyway. Hydroplaned and spun out on the test drive. All in all, glad to habe not died and got her runnig good again, but sooo bummed about the paint.

[madkaw]

Lesson to be learned here-check and double check the basics first before going crazy on the troubleshooting.

[Captain Obvious]

Haha! Excellent! Glad you got to the bottom of that and that it was such an easy fix.

PS - I bet that would have showed up in a good pic of the engine bay.

[ninjazombiemaster]

Lesson to be learned here-check and double check the basics first before going crazy on the troubleshooting.

I checked so many times!!! I can't believe I missed it.

Haha! Excellent! Glad you got to the bottom of that and that it was such an easy fix.

PS - I bet that would have showed up in a good pic of the engine bay.

Haha, me too on all counts.

[SteveJ]

Yeah. Ive got 5-20 weight in it. Couldnt find a better option locally. It seems like it doesnt really kick in soon enough, like the lowest bit isnt dampened, causing a lean mix. Im pretty sure I got plenty in there, they are pretty hard to move. I really am wondering about vaccuum leaks but all thats changed is the carbs, and all the bolts are tight, I checked that yesterday. Being that nothing changed but cleaning the carbs, changing the starter motor, and plugs. I dont see how a vaccuum leak wouldve developed, but I'll look for one

Sorry I didn't respond sooner. Popular places to find 20wt oil are at Ace Hardware (3-in-1 oil) and at motorcycle shops (fork oil).

[ninjazombiemaster]

Sorry I didn't respond sooner. Popular places to find 20wt oil are at Ace Hardware (3-in-1 oil) and at motorcycle shops (fork oil).

Thank you. I mixed some 10-40 with it and it seems to do it for now. I still have a hard time starting, and poor behavior when cold - but I'm not really sure what is normal performance in below freezing weather. Most notably, it seems to be running out of power at certain speeds in each gear, eg. In 2nd gear, it totally loses power at 50 MPH. You can hear a sputtering, that sounds like fuel but its hard to say with such a noisy ride (but if I had to compare it to something, it felt like it ran out of gas.. perhaps the floats are indeed set so the bowl depletes too quickly? Its got an electric fuel pump that seems to work splendid.). Then, switching to 3rd, it'll go strong until 90 MPH then sputter. And I don't mean it just hits the end of its power curve. More like it reaches an RPM and then loses something, like not enough fuel or not a hot enough spark. Vacuum advance seems to be working still.

[Stanley]

When it starts to lose power you could try pulling the choke lever back about half way. If that "fixes" it so you can rev higher, the carbs (or one carb) might be set too lean, so raise the floats or lower the nozzles. Thought I had mine set perfect, but a run this afternoon against my neighbor's crx proved otherwise - it's doing the same thing as yours - pulled the choke and was getting power for another 700 rpm - so I'm gonna drop the nozzles 1/4 turn and try again.

[ninjazombiemaster]

I'll give that a try and see what happens. When I watch it move, my choke seems to work right, but I'm not so sure its working properly from my cars behavior when its pulled. Sometimes its as expected, others, it actually drops the RPMs. But that's an issue of its own.