missing heavy under light load.

[brettvr4amos]

Hi guys I am new to the forum. I did a search for this problem but couldn't get anything that was the same.

The car. 98 legnum manual.

The problem. After driving the car for longer than 30 min. It starts to miss and splutter in every gear above 2500 rpm.
The first time it happened I pulled over and checked all pipes and vacume lines everything. All checked out. So I kept driving it slowly to get to the next servo. When I got there I turned the car off and had another look. All seemed fine. So I started the car and thought ill just baby it home and check the forums. I had to pull up a hill and noticed it didn't do iSo I slowed right down and put it in first and went through all the gears. All was back to normal. Didn't think any more about it. But today she was hard to start. The starter is going good but slow ingnition. Drove the car and it semmed fine. I wasnt up it really as I had my in-laws in the car. Then after 30min of driving back to missing and splutters through all gears so I turned the car off to see if it went away. Left it for ten min it took three attempts to start the car ran ok but within ten to 15 min it was back to missing and carrying on.


Anyhelp with this would be great.

Thank you

Brett

 

[naughtika]

I think your plugs are stuffed.. check and replace if required...

 

[brettvr4amos]

I just brought the car last weekend. Apparently the plugs are less then 10 thousand ago. I orded New plugs and leads just waiting for the leads and will replace. Cheers

 

[godzilla]

10000 is a fair bit especially if they're cheap and nasty ones.

 

[brettvr4amos]

Yeah true. Just down the coast atm and haven't got any tools and plugs here I will have to do it first thing Monday fingers crossed the leads turn up on Monday. Cheers. Will keep ya posted. Have a feeling it could be the igniter as well. Not 100% sure though.

 

[VOLK]

Plugs or coil packs.

 

[brettvr4amos]

Will check that to. I have notice if the indicator is on the the fuel pump, which is a walbro, will go up and down with the change in the indicator going on and off. Dam hope the alternator isn't shagged dam things are crazy expressive. Cheers

 

[VOLK]

Pump wavering with indicator is normal.

 

[Guest]

That's normal operating with the Walbros

Pull out one of your front plugs and have a look at the condition of them and also the type used. If they were last replaced with coppers they will already be dead, platinums don't last a heck of a lot longer either. The iridiums, despite some claiming 100,000kms, will actually last for about 40,000kms before needing replacement.

Then there are the lazy places that only replace the front plugs and can't be bothered doing the rears. But the rears are ones most likely to cause trouble due to excessive heat - plus oil leaks into the tubes from the heat hardening the gaskets around them.

 

[brettvr4amos]

Could be plugs as its running rich also but that started when the first issue started.

 

[brettvr4amos]

This is ten times harder to fix than my supra. I got a full set of k22 of the forum. I know the rear bank rocker cover is leaking slowly. Which is getting fixed in at the 200,000 service in Jan. I ran twin walbros in my supra and they where no where near as loud as this one. This pump is as loud as the twin 044 in my supra. Is that normal. Cheers

 

[VOLK]

My Walbo's also loud. Down right industrial when priming (ignition on start but clutch not in) and others have said the same so I'm assuming normal.

Also re: difficulty of working on them; welcome to transverse Mitsubishi V6s It doesn't really get easier, you just get faster and more familiar.

 

[vr4cobra]

Its different per car id say as I cant ever hear a whisper out of my walbro its not the most fun job to do as I found out when I did my plugs so I have a pile of seals for rocker covers, fuel rails and new leads to put on but im waiting till I get valve stem seals aswell and possibly lifters even tho mine arnt that noisy just there sometimes lightly ticking away wat im saying is most ppl just compile as many things they can do while the intake is outta the way and to nutz doing everything at once so we dont have to rip it all apart again and again lol

good luck with it tho hopefully it is only plugs, u can also check if ur coils and arc out by Christians lil guide of squrting his stuff on them to check on my phone now so cant send u the link

 

[brettvr4amos]

when you guys talk about priming, what should i be doing, as my supra the 044 turn on not start and the pumps start going. i know thats not safe but makes it easier with starting the car on e85. with the legnum i turn the car to on like the supra then what do i do, cheers. also pulled the front plugs out they look like they have suffered heat soak pretty bad not sure if they are 100% shaged will put a pic up when i am done they are ngk iridium bkr6eix-11. the new leads havent rocked up yet so just going to clean the old ones and put it together as the missing is getting worse and happening more. the coil packs have had the mod done so fingers crossed it not them. i am chasing up new ones through a group buy in the forum but have to wait untill jan next year which ok as the car goes in for its 200k service on the 21st of jan 2013. so will do the whole lot then. just started pulling the inlet off might have a look through here for a write up and see if there is a step by step so i don't shag anything haha.

will keep ya posted cheers guys.

 

[steveP]

This link might help a little regarding spark plug health.

http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

 

[naughtika]

Christians lil guide of squrting his stuff on them to check

must resist....

*my apologies.. a bit off topic*

 

[fieldy107]

they are ngk iridium bkr6eix-11.

Could be your problem right there. Those plugs have the wrong gap, 1.1mm as indicated by the -11. You should be running bkr6eix (no -11 at the end) which are gapped at 0.8mm. That alone wont cause your car to run that badly, but wrong gap in combination with poor condition plugs could be your issue.

 

[Schneider]

1.1mm gap is factory. We switch to 0.8mm because most of us get our cars tuned and run higher boost. In saying that smaller gaps will help if your coils are starting to fail.

 

[VOLK]

Chris sure does love those coil packs

 

[fieldy107]

1.1mm gap is factory. We switch to 0.8mm because most of us get our cars tuned and run higher boost. In saying that smaller gaps will help if your coils are starting to fail.

Are you sure of that? I haven't actually looked in the manual but everything on OZVR4 recommends 0.8mm even on a stock standard car.