1990 Nissan 300ZX Logo
Posted on Oct 18, 2008
Answered by a Fixya Expert

Trustworthy Expert Solutions

At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.

View Our Top Experts

300zx engine idle

Hi there i have a 1990 300zx fairladyz. its non-turbo. the timing belt snapped recently which me and my dad managed to replace.the car started ok but was running ruff. so we knew that we had bent valves . we opened the engine , found out 2 exhaust valves and 2 inlet valves were bent in cylinders 4 and 6 . got the heads refaced , valves reseated . we put in new water pump , idler pullys , tensioner pulley , timing belt . car started fine but the engine rpm was a bit high . we played with the crank angle sensor and t.p.s also to get a little lower rpm , but still not very happy. the car sometimes doesnt wanna start , and i noticed that i have to quickly start car without any speed appication . which does help so iam thinking that the fuel mixture is too rich. ive ordered the consult cable from ebay US to acheive a better tunning. now my exhausts have also given up so i have to replace them. the engine sounds pretty good when the car is running. yeh the important bit also is that as soon as you wanna engage in gear (auto) and take off the car stalls a bit and then goes. it stalls everytime i wanna take off. please help .

  • Anonymous Mar 24, 2014

    the car runs just fine when its cold but after it warms up a bit it runs like ****. ive changed the fuel filter and regulator and its better, but still not great.. I need help!

  • Jeremiah Okwanyo
    Jeremiah Okwanyo May 15, 2014

    do the clen up for injector nozles,they are also affectd because of the cloged filter(fuel)

×

5 Answers

Anonymous

Level 3:

An expert who has achieved level 3 by getting 1000 points

Superstar:

An expert that got 20 achievements.

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

  • Master 1,586 Answers
  • Posted on Oct 19, 2008
Anonymous
Master
Level 3:

An expert who has achieved level 3 by getting 1000 points

Superstar:

An expert that got 20 achievements.

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Joined: Jul 21, 2008
Answers
1586
Questions
0
Helped
821383
Points
5018

The reason it's stalling out is because of the adjustments you made to the CAS and TPS. You need to reset the CAS where it was, since when you rotate this sensor, you change the ignition timing. As for the TPS, that also needs to be reset to how it was. The way to adjust the idle on this engine is with a screw on the idle air control valve (IACV). At the back corner of the engine, on top on the driver's side, the IACV is bolted on. If you crouch down next to the driver's fender and look straight in at the IACV (with a flashlight) you will see a screw recessed in there, with the head pointing toward you. That's the idle adjustment screw. With the engine running, AFTER you have reset the CAS and TPS, turn this screw until you are able to set a warm-engine idle of roughly 750 RPM. Messing with TPS voltage and ignition timing is a sure-fire way to stall or blow up your engine.

Anonymous

Level 1:

An expert who has achieved level 1.

Mayor:

An expert whose answer got voted for 2 times.

  • Contributor 1 Answer
  • Posted on Jun 13, 2009
Anonymous
Contributor
Level 1:

An expert who has achieved level 1.

Mayor:

An expert whose answer got voted for 2 times.

Joined: Jun 13, 2009
Answers
1
Questions
0
Helped
4522
Points
5

U need to do as j_del says... only a couple things he missed. to properly adjust the idle, u need to warm the car up to normal operating temp, unplug the iacv then turn screw to adjust. u want it to idle about 650-700, all else he says is true.

Ad

Anonymous

Level 2:

An expert who has achieved level 2 by getting 100 points

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Vice President:

An expert whose answer got voted for 100 times.

  • Expert 55 Answers
  • Posted on Oct 29, 2008
Anonymous
Expert
Level 2:

An expert who has achieved level 2 by getting 100 points

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Vice President:

An expert whose answer got voted for 100 times.

Joined: Oct 29, 2008
Answers
55
Questions
0
Helped
73897
Points
299

With 10 years experience in a Nissan dealership, I agree with j_del... you shouldn't mess with the CAS and TPS... but I'm not sure that messing with the IACV will properly correct this issue.

Did you check for vacuum leaks? The idle speed should not have changed after you replaced all these parts. But, a vacuum leak would lead to the higher idle speed and stalling you described. There's lots of vacuum lines on these engines and it's easy to miss one. Propane enrichment is one way to look, but I prefer to let the engine idle and spray small amounts of carb cleaner (any parts store) around different areas of the engine and listen for a change in idle speed. That'll help you pinpoint the source. Again, do this AFTER you reset the CAS and TPS.

Anonymous

Level 1:

An expert who has achieved level 1.

  • Contributor 1 Answer
  • Posted on Jul 02, 2010
Anonymous
Contributor
Level 1:

An expert who has achieved level 1.

Joined: Jul 02, 2010
Answers
1
Questions
0
Helped
4522
Points
2

I have a 90 300zx non turbo auto the tranny shift late from first to second in normal driving is there a way to adjust the kickdown or what controls when to shift

Anonymous

Level 1:

An expert who has achieved level 1.

  • Contributor 1 Answer
  • Posted on Jun 16, 2009
Anonymous
Contributor
Level 1:

An expert who has achieved level 1.

Joined: Jun 16, 2009
Answers
1
Questions
0
Helped
4522
Points
1

I am overhauling ma engine. anyone knows wer to find the timing specs or diagram? im on the process of putting ma timing belt on. altho i have marked ma timing gear, i just wanna check it on the specs.. thank you

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
1answer

I have a 1990 300zx non turbo automatic if the car starts off in "D" the car starts off in 2 or 3 gear and stays in the gear im doing 80 with a rpm at 5000 but when i start the car off in "1" it takes

The aged engine needs to be replaced. Look for an aftermarket used and reconditioned engine. Have a station lift your out and replace it with a good engine. Could cost $1000 or more.
2helpful
1answer

I have a high idle on my Nissan 300ZX what could cause this?

I have a Nissan 300zx twin turbo 1990.... The engine and car are in very good condition ... well serviced... The idle speed will not go below 2000 rpm can you help as there is no manual adjustment...????
1helpful
1answer

How to change flywheel on 1990 300zx non turbo?

pull the transmission. remove the torque converter (automatics) or clutch and pressure plate (standards), the bolts for the flywheel are under that. make sure you replace the flywheel with the proper one especially if it's a standard.
1helpful
2answers

1990 300zx non turbo 150,000 miles developed a rattle or knock or a tick.... seems to change.... but not at idle at all. It seems to be loudest at the point of rpm increase very slowly and not when you...

Obvioustly check to make sure that you have oil in it. If thats OK then remove all drive belts and retest for noise. Could be something else such as A/C compressor. Let me know what you find.
2helpful
2answers

1990 300zx non turbo has miss on 2 cylinders

dude, i think you have two spark plug cables cross over. go to your local autozone and find a "firing order" if it was a blown head gasket it would show on the compression test but i'm pretty sure its a spark plug cable cross over.
0helpful
2answers

90 300zx turbo or non turbo? ??

look for the turbo under the hood it looks like a snail kinda
0helpful
1answer

1990 300zx N/T Clutch not engaging properly

Your Friction disk (clutch) is worn out. Have it replaced....might also need pressure plate, but not necessarily.
1helpful
1answer

Timing diagram

You have Nissan's VG30DE engine in your car. If you go to www.ttzd.com (Twin Turbo Z's of Dallas), you'll find Tech articles for the 300ZX (the non-turbo version is the same engine that you have). One of the articles is the full timing belt service job. I believe it was done on a twin turbo, but for purposes of the timing system, the turbo and non-turbo are the same. It'll give you all the info, pictures, tool lists, and step by step instructions that you could want or need.
Not finding what you are looking for?

4,532 views

Ask a Question

Usually answered in minutes!

Top Nissan Experts

ZJ Limited
ZJ Limited

Level 3 Expert

17989 Answers

Thomas Perkins
Thomas Perkins

Level 3 Expert

15088 Answers

Arnie Burke
Arnie Burke

Level 3 Expert

7339 Answers

Are you a Nissan Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...