TylerFYI

So i know the distributor cap and plug wires are bad, but whenever i start my car it seems like it idles at the rev limiter. Just wondering if anyone has had this problem before/knows how to fix it. Everyone says it could be a vacuum leak but it just seems a little high to be that. Any help is appreciated!

zxguy1986

Welcome to ZDriver!

You're asking for shots in the dark here. A little more info on the car would help.

If the dist cap and wires are 'bad' why don't you replace them? Sounds like they would be step #1 in getting your new Z to run right.

The Z31 has a cold idle (high) and a warm idle (lower). It drops automatically when everything is working right. If you do have vacuum leaks, that and lots more stuff will not work right. The Z31 vacuum system is a big deal, if that's one of your problems.

Nobody ever bought a Z that was perfectly tuned and running at 100% perfect. You have to catch up now on all the regular maintenance the PO didn't do. Before he sold it, he stopped caring about it. You care now - so stick with it and when you finally get it back to that 100% place, you will be amazed. Use the freebie factory service manual you got at http://www.xenonz31.com/reference.html Full of great testing and troubleshooting pages, easy to follow.

Welcome again - and tell us more

rogerz

since I am waiting on a hvac guy to show and have nothing better to do try reading this and then making a post that has some coherence. :Get your battery load tested. Be sure you have clean, tight corrosion free terminals on both ends of your battery cables. Be sure the ground (negative) cable goes to a bolt into the frame before going to the starter. grounding through the starter is not a reliable connection. Z's don't like low voltage. causes the electronics to act funny. it is possible to have enough amps to crank but not enough voltage to run the electronics. If you have one size fit all cheapo clamp on terminals they are a problem waiting to happen. Usually on a rainy night around Oh Dark Thirty.

Clean the connectors for the maf or afm, ecu and tps. Deoxit by CAIG is probably the best connector cleaner on the market. spray with CorrosionX after cleaning and before putting together this will help prevent any further corrosion. DON'T USE DIELECTRIC GREASE.

Replace outer tie rod ends, and ball joints. replace the bushings with poly (don't forget to lube them as directed unless you like squeaky things). New shocks. Get new boots for power steering. all those things will make you think you are driving a different car. doing them piece meal is a waste you won't see a great improvement until you do the complete job. You need to get the car realigned after messing with the front. Have your tires in good shape and rebalance. Rear bushings nice too but more work and you won't notice as great an improvement. Rear shocks also because if the fronts are gone so are the rears. if car squats when you jump on the gas the rears are gone. If you have the electro adjustable shocks they are DEFINITELY GONE.

if you would really like answers that would help you and avoid flames give the following info when you post: year of car, n/a or turbo engine, stick or slushbox. Most of us can tell by the year what model you have ie 85T is a turbo z31. Z cars come in many flavors and they are all different. example 84,85,86 Z31's pretty comparable. there were changes in 87,88,89. in addition 300ZX can refer to two completly different cars the Z31 and the Z32. No mindreaders here the more info you can post the more likely you get a cogent useful answer. The cars with L engine (straight six) changed almost yearly from their introduction. A 240Z and and a 280Z have similarities but they can also have wide variance.

ken99

This would be imposable without the throttle body stuck open. I'd start by checking the status of the throttle body butterfly valve. I'd then check the condition of the throttle body cables (one for the pedal, one for the cruise control) and the condition of the return spring that pulls the TB shut you let off the accelerator.

TylerFYI

Sorry for the vague post, half asleep lol, i have a 86 base with the stock vg30 n/a with the manual tranny. This was really a shot in the dark to try and get it running asap but the distributor, wires, and plugs are on the way and i tested the battery at work and it is for sure a p.o.s. I took most of the intake off to look at the throttle body and everything seemed functional. I have plans to clean the entire manifold anyways, but i only have about 1-2 hours a day after work to work on her. I did have a chance today to look at the canister behind the passenger headlight and the top 3 lines all had vacuum but the bottom one did not, is that normal? Also the poly bushings are definitely going on as soon as i can get it running right again lol

TylerFYI

I dont think its at the rev limiter but i have a digi dash and the power supply is no were to be found lol. I already have a analog and dash pod gauges to swap out when i have the time

rogerz

you can't just swap in the analog stuff. better to look at ebay or whatever and find a power supply. There is a speed limiter on turbo cars but no rev limiter that I know of.

TylerFYI

ZBUM's Z31 300ZX Digital to Analog Dash Conversion
Saw this and was going to try it