Elusive Misfire

[EdGasket]

Hmmm interesting; I hope that really is it for you but difficult to see why carbon there should cause a misfire. I mean once the throttle is open it just lets air through right, so what does a bit of carbon on the inside edges of the throttle body matter, the air is going to sail straight past it? Maybe someone can explain whats going on here?

[santa06]

Isn't there an IAC, idle air control on the intake , small pintal stepper motor that varies air flow , mounted on the intake; gets gummed up eventually. Maybe the 2000 model doesn't have one.

[EdGasket]

Originally Posted by santa06

Isn't there an IAC, idle air control on the intake , small pintal stepper motor that varies air flow , mounted on the intake; gets gummed up eventually. Maybe the 2000 model doesn't have one.

He says he already changed that; see about 6 posts previous

[jsinton]

Yeah, I changed the IAC three times actually. The issue was it would only miss at low power, meaning as I feathered the pedal back to try and save gas (like I always do to get my great Fuelly.com scores), so even a small amount of carbon build up around the seal made a huge difference. Mind you, it took a little time to break it all loose with an old tooth brush and carb cleaner, but it could have been done with the intake still bolted up to the manifold with a little effort. I had only the ENTIRE intake assembly to buy (which I almost did... and that would have fixed it:

99 Hyundai Elantra 2 0 DOHC Complete Intake Manifold with Fuel Injection System | eBay

And the ECU was on the way and should arrive any day:

99 00 Elantra Engine ECM | eBay

And if all that didn't work... I would have trashed the car as I need a car that I can trust for the big trip... either to Maryland or California.)

I was going to look at an XG today:

2001 Hyundai XG300

[EdGasket]

Dunno about the US but in the UK its absolutely no good buying an ECM because thet are matched to the immobiliser and keys. So if you need a new ECU(ECM) you are looking at an immobiliser plus a set of keys and lock barrels to go with it. The immobiliser is coded to the blue master key.

[jsinton]

Yeah, I've never seen an RD Elantra with an immobilizer setup. Almost like they figured nobody would ever possibly want to steal these cars in the States. They had a reputation at the time as the cheapest cars on the road. No self respecting thief would want to be caught dead in one methinks.

[EdGasket]

It's been compulsory here since 1997 for manufacturers to fit an immobiliser to deter car theft. Another cost pushed onto the consumer making us all victims of crime (Some car keys cost hundreds due to the immobiliser complications). If the Gov. and police here had a more robust approach to car crime and punishment we wouldn't need immobilisers would we.

[santa06]

Originally Posted by EdGasket

It's been compulsory here since 1997 for manufacturers to fit an immobiliser to deter car theft. Another cost pushed onto the consumer making us all victims of crime (Some car keys cost hundreds due to the immobiliser complications). If the Gov. and police here had a more robust approach to car crime and punishment we wouldn't need immobilisers would we.

Immobilisers now mandatory here across the pond in new cars; whining from insurance company losses etc so cost passed on to cars owners. Reduced insurance premiums haven't shown up yet---what a surprise.

[jsinton]

That's interesting. You guys must have had a big problem with car theft, or the insurance companies and car companies "preloaded their career" and pushed the issue. I replaced the ECU with no issues, but it didn't fix my problem.

[santa06]

What did you say the engine compression was again ; I think you posted it somewhere.

Low compression can affect driveability, idle even more so.