Hi, I am new to this forum and thought i'd put out a scream for help!!! I have just brought my first 300zx tt, manual uk edition. The problem is I have no power..... So on standstill it misses noticeably and when under load it splutters really badly which is no fun!!! Can somebody please help guide me and also is there any 300zx specialists local to me? (North London)

Thanks

Hi there. Welcome to the forum. Have you checked anything specific yet

Hi mate, I've checked the plugs and coil pack so far and all seem sweet. I've done a bit of searching and I see it may be worth checking the ptu????? Any ideas?

 

- - - Updated - - -

 

Also checked compression on all cylinders and sweet.....

Try checking the ecu for codes

Try checking the ecu for codes

 

ECU is clear, no codes shown...

Don't think it's a boost leak otherwise it wouldn't miss on idle. Or would it? If you accelerate gently it drives ok but the second you floor it, it all goes wrong... It hesitates massively

Next try injectors, put a long screwdriver on the top of each and your ear on the other end of the screwdriver. Should hear them "clicking" and should all sound the same

Hi mate, welcome to the forum :thumbup1:

 

Good advice above on the injectors, 6/6 is ideal. A boost leak, or rather an "air" leak, could make it run badly throughout, it is a right snake's orgy under that bonet, pipes going all over the place. They experience mild and strong vacuum, then mild and strong positive pressure. It could be drawing in un-metered air at idle, then might be alright under other conditions, before leaking boost under load.

 

So I wouldn't rule it out. Let us know how you get on :clover:

I had a split intake pipe on my turbo Capri, it was fine till it was on boost where it opened like an eye and faultered massively. It wasn't obvious as it was a thick pipe and a 1 inch slit down the side. Took quite a squeeze to open it up.

Next try injectors, put a long screwdriver on the top of each and your ear on the other end of the screwdriver. Should hear them "clicking" and should all sound the same

 

Thanks mate. Will give it a go and update soon as

Welcome to the club and hope you get it sorted soon.:thumbup1:

Welcome to the club and hope you get it sorted soon.:thumbup1:

 

Thanks for the welcome pal. Any ideas re: hesitation under heavy acceleration?

Could be lots of things mate, have a look at the second post in this thread.

http://www.300zx.co.uk/forums/showthread.php?602-Pull-away-delay&highlight=hesitation+heavy+acceleration

Could be lots of things mate, have a look at the second post in this thread.

http://www.300zx.co.uk/forums/showthread.php?602-Pull-away-delay&highlight=hesitation+heavy+acceleration

 

Won't allow me to gain access to the post. Says I don't have permission..... :confused1:

Yeah Gary, what's this private post about? Mods section or something?

Ah its in the old archive section I will cut and past the post that is relevent.

 

 

 

Stu, here's some information I borrowed from another site :-)

 

Why does my Z32 hesitate sometimes?

 

This is long and semi-complicated. Here are things to consider in a general order of increasing unlikeliness:

 

Clean the TPS (Throttle Position Sensor)

Clean the air filter

Clean the injectors

Change the spark plugs

Change the fuel filter

Clean the Crank Angle Sensor (CAS) connector

Clean the Throttle Bodies

Clean the detonation sensor connector

Clean the Mass Airflow Sensor (MAS) connector

Induce turbulence in the air intake

Clean the coolant temperature connector

Change/add coolant

Clean intake valves

Do you have an updated Power Transistor?

Is it a 1990 model?

 

Clean the TPS (Throttle Position Sensor)

The TPS is located on the driver's side of the engine. Look at the throttle body, it's the big box with the huge rubber intake hose going into it. The TPS is the small black plastic box on the side of the throttle body with wires coming out of it. The connector is held on by a little wire spring/clip. Use a small screwdriver or something to pop it off. Be very careful when doing this; don't lose it, it WILL go flying if you're not careful!

 

 

 

When removed, it might have green corrosion on the electrical connectors. Go to Radio Shack and buy connector/contact cleaner, or just use some ultrafine grit sandpaper, just get rid of that corrosion! Make those connectors shine and then reinstall the TPS. Corroded TPS connections are some of the most common causes of hesitation.

 

Time required: approximately 15-20 minutes.

 

 

Clean the air filter

This procedure is illustrated on http://www.ttzd.com.

 

Time required: 10 minutes for stock airbox; 1 or 2 hours to clean the K&N and let it dry.

 

 

Clean the injectors

Many people will come out and say the injectors should only be cleaned professionally by removing them. Nissan also says this. However, for the DIY'er, purchase a bottle of Chevron Techroline or some Red Line injector cleaner and run it through according to directions.

 

 

Change the spark plugs

This procedure is illustrated on http://www.ttzd.com.

 

It may be a good idea to at least PULL your plugs to inspect them, since as they age they will take on characteristics that vary based on the health of the engine.

 

The following is from the NGK homepage:

 

Reading spark plugs can be a valuable tuning aid. By examining the Insulator firing nose color, an experienced engine tuner can determine much about the engine's overall operating condition.

 

In general, a light tan/gray color tells you that the spark plug is at the optimum temperature and that the engine is in good operating condition.

 

Dark coloring, such as heavy black wet or dry deposits usually indicate a fouling problem. Heavy, dry deposits can indicate an overly rich condition, too cold a heat range spark plug, possible vacuum leak, low compression, overly retarded timing, or too large a plug gap.

 

If the deposits are wet, it can be an indication of a breached head gasket, oil control from rings or valvetrain problems, or an extremely rich condition, depending on what liquid is present at the firing tip.

 

One must also look for signs of detonation, such as silver specs, black specs, or melting or breakage at the firing tip.

 

Signs of fouling or excessive heat must be traced quickly to prevent further deterioration of performance and to prevent possible engine damage.

 

 

Here are some ideas for what you might see:

 

 

Thanks to CarloZ for the link info.

 

 

Change the fuel filter

This procedure is illustrated on http://www.ttzd.com.

Ah its in the old archive section I will cut and past the post that is relevent.

 

 

 

Stu, here's some information I borrowed from another site :-)

 

Why does my Z32 hesitate sometimes?

 

This is long and semi-complicated. Here are things to consider in a general order of increasing unlikeliness:

 

Clean the TPS (Throttle Position Sensor)

Clean the air filter

Clean the injectors

Change the spark plugs

Change the fuel filter

Clean the Crank Angle Sensor (CAS) connector

Clean the Throttle Bodies

Clean the detonation sensor connector

Clean the Mass Airflow Sensor (MAS) connector

Induce turbulence in the air intake

Clean the coolant temperature connector

Change/add coolant

Clean intake valves

Do you have an updated Power Transistor?

Is it a 1990 model?

 

Clean the TPS (Throttle Position Sensor)

The TPS is located on the driver's side of the engine. Look at the throttle body, it's the big box with the huge rubber intake hose going into it. The TPS is the small black plastic box on the side of the throttle body with wires coming out of it. The connector is held on by a little wire spring/clip. Use a small screwdriver or something to pop it off. Be very careful when doing this; don't lose it, it WILL go flying if you're not careful!

 

 

 

When removed, it might have green corrosion on the electrical connectors. Go to Radio Shack and buy connector/contact cleaner, or just use some ultrafine grit sandpaper, just get rid of that corrosion! Make those connectors shine and then reinstall the TPS. Corroded TPS connections are some of the most common causes of hesitation.

 

Time required: approximately 15-20 minutes.

 

 

Clean the air filter

This procedure is illustrated on http://www.ttzd.com.

 

Time required: 10 minutes for stock airbox; 1 or 2 hours to clean the K&N and let it dry.

 

 

Clean the injectors

Many people will come out and say the injectors should only be cleaned professionally by removing them. Nissan also says this. However, for the DIY'er, purchase a bottle of Chevron Techroline or some Red Line injector cleaner and run it through according to directions.

 

 

Change the spark plugs

This procedure is illustrated on http://www.ttzd.com.

 

It may be a good idea to at least PULL your plugs to inspect them, since as they age they will take on characteristics that vary based on the health of the engine.

 

The following is from the NGK homepage:

 

Reading spark plugs can be a valuable tuning aid. By examining the Insulator firing nose color, an experienced engine tuner can determine much about the engine's overall operating condition.

 

In general, a light tan/gray color tells you that the spark plug is at the optimum temperature and that the engine is in good operating condition.

 

Dark coloring, such as heavy black wet or dry deposits usually indicate a fouling problem. Heavy, dry deposits can indicate an overly rich condition, too cold a heat range spark plug, possible vacuum leak, low compression, overly retarded timing, or too large a plug gap.

 

If the deposits are wet, it can be an indication of a breached head gasket, oil control from rings or valvetrain problems, or an extremely rich condition, depending on what liquid is present at the firing tip.

 

One must also look for signs of detonation, such as silver specs, black specs, or melting or breakage at the firing tip.

 

Signs of fouling or excessive heat must be traced quickly to prevent further deterioration of performance and to prevent possible engine damage.

 

 

Here are some ideas for what you might see:

 

 

Thanks to CarloZ for the link info.

 

 

Change the fuel filter

This procedure is illustrated on http://www.ttzd.com.

 

 

Appreciate that Gary, will go though this step by step this week and hope for a positive outcome. :detective:

Overall sounds more like a MAF problem or a CAS problem

Possibly a wet MAF

Use Consult to check sensor values first of all. Saves a great deal of time at the beginning of proper diagnosis. Measuring the AFR is very important as well.

Sound exactly like the problem I had on my original zed, rainwater on the MAF!

To test mine, tony and sir Charles theory, just unplug your MAF and see if the idle settles down

I had same problem years back turned out to be an injector, pulled coil pack leads of in turn found no6 made no difference to the engine idel when off, I also changed all the injector connectors were very green.

Thanks mate. Will give it a go and update soon as

 

All clicking the same pal. Spark plugs all sparking.... Coil pack is sweet. Cleaned ptu and tps but no difference.....

Consult cable, diagnose properly. Even if you get lucky by finding the issue via unplugging, replugging, cleaning and hoping, chances are you'll have another issue down the line which can again be potentially solved within minutes :)

 

All connectors should be cleaned as a matter of course, all adjustable sensors should be correctly positioned as a bare minimum. If you put the car under load when it's running so poorly, you may cause severe engine damage. Then again, you may not...

Consult cable, diagnose properly. Even if you get lucky by finding the issue via unplugging, replugging, cleaning and hoping, chances are you'll have another issue down the line which can again be potentially solved within minutes :)

 

All connectors should be cleaned as a matter of course, all adjustable sensors should be correctly positioned as a bare minimum. If you put the car under load when it's running so poorly, you may cause severe engine damage. Then again, you may not...

 

Consult cable??? What is this? And thanks for the input, much appreciated