Strange Performance Loss

[Tazino]

Hi,

 

I was crusing along on the Motorway at 70MPH and suddenly the Z began to loose power, with some juddering/jerking, the speed slowed down to about 50MPH and returned to normal, it happened 2/3 times, what can this be? Any idea? I thought I was about to brake down, by the loyal 300ZX managed to get me home. The driving surface was flat throughout.

 

What needs to be checked? The car is otherwise in good condition. 1998 60K twin turbo manual, import.

 

Thanks

[dutchgold92]

Could be a lot of things - best to check for codes. Yours will have OBD2.

[Medallion Man]

agreed... when was the last service and have you done any PM on it... a good clean of all connectors and checking all vac lines is a good start..

 

good luck.

[JeffTT]

Was you driving in rain or road spray ? do you have an induction kit? if so very likely the maf was getting wet and causing fuelling issue.

 

Jeff

[Tazino]

Thanks for this, it was raining pretty heavy. How can I cure, do I need to consider replacing the induction kit and/or maf?

[Gaz 300]

Thanks for this, it was raining pretty heavy. How can I cure, do I need to consider replacing the induction kit and/or maf?

 

Is it running ok now that it has dried out?

[JeffTT]

Thanks for this, it was raining pretty heavy. How can I cure, do I need to consider replacing the induction kit and/or maf?

 

The issue is caused by the fitting of particular short filter induction kits and best option is to fabricate a shield so direct water laden air is diverted and not blown directly onto the filter when driving forward, if you have a vented front panel consider blocking it off or changing back to standard, they can cause more trouble than good when fitted in conjunction with a short induction kit.

 

The reason the problem occurs is the water changes the temperature of the hot air wire and thus giving false information about what air is entering the engine, the ecu trys to fuel for this and of course makes a bad job of it.

 

Also worth remembering, repeated events that wet the maf will cause it to fail eventually, hopefully on this occasion when it dry`s out all will be fine.

 

Jeff

[Sir Charles]

I had a similar issue a while back

 

http://www.300zx.co.uk/forums/showthread.php?139352-Rainwater-causing-me-problems

[Gaz 300]

Is it an HKS filter (can be double or single) as they don't like getting wet. Jeff's post above is your answer to the problem.

 

[JeffTT]

In general the twin filter induction kits do not suffer from the problem the same way as the short filter option.

 

Jeff

 

 

[AndrewG]

My way of dealing with the problem (now two for the dual maf setup), is have the HKS filters mounted as high

as possible behind the '89 spec bumper and the upper slot in the bumper covered by the number plate.

 

 

[Gaz 300]

My way of dealing with the problem (now two for the dual maf setup), is have the HKS filters mounted as high

as possible behind the '89 spec bumper and the upper slot in the bumper covered by the number plate.

 

[ATTACH=CONFIG]93271[/ATTACH]

 

[ATTACH=CONFIG]93272[/ATTACH]

 

That's a great setup Andrew.