Hesitation Problem

Volatile · Post by **Volatile** » Tue Dec 13, 2005 6:54 am

Hey,

I just bought a toyota corolla liftback with 4A engine.

It has a pretty bad hesitation/miss between 2000-3500rpm, what should i start checking/replacing?

first thought was plugs?

Thanks

James

AJz · Post by **AJz** » Tue Dec 13, 2005 9:46 am

if you have just bought it i would start replacing these anyway cos you dont know when they were last changed, there have been many threads covering this but but a quick list would be....

Plugs - just genuine replacement ones, dont need any fancy platinum shit.
Leads - Again, toyota genuine the best bet. some people get a set of champion or Top Gun leads.
Dizzy Cap - most likely its still the factory one. (where your leads plug into)
Dizzy Rotor - thing that spins inside dizzy, again probably stock.

see if that helps, all are pretty straight forward to change, just need the tools.

Volatile · Post by **Volatile** » Fri Dec 16, 2005 7:02 pm

UPDATE,

I pulled the plugs out and they seem fine, good gap etc.

What does white dust/crap on spark plugs indicate? (running lean?)
could this be the cause of my missing/hesitation problem? (ie fuel)

I've done some more driving and i don't notice the missing in 1st gear but in second it's definately there as soon as you hit 3000rpm

Ae92typeX · Post by **Ae92typeX** » Fri Dec 16, 2005 11:13 pm

white white does indicate lean & can cause a misfire as well as worse things in the long run. can also be various other meanings.
have a look here:
http://www.motocross.com/motoprof/moto/ ... /plug2.htm
or here
http://www.theultralightplace.com/sparkplugs.htm
for a quick guide on reading plugs. The first link is probably the better of the two for a basic understanding

could also be worth checking that they are actually the correct ones for the engine- someone may have put an incorrect heat in & they are cheap as to replace anyway.
really, as you just got it, doing all the basics listed above is good practice anyway.

BZG Wagon · Post by **BZG Wagon** » Sat Dec 17, 2005 9:55 pm

Try spraying CRC Clean-a-Carb into the Throttle Body. Open the butterfly right up and spray some in, possibly clean parts of the throttle body out with a rag. Then start the car up (it may not start first time; but it will start) and spray some in whilst the car is running. Then connect up the air intake system back up.

I find this usually make a huge difference.

Volatile · Post by **Volatile** » Sun Dec 18, 2005 9:54 am

BZG Wagon wrote:Try spraying CRC Clean-a-Carb into the Throttle Body. Open the butterfly right up and spray some in, possibly clean parts of the throttle body out with a rag. Then start the car up (it may not start first time; but it will start) and spray some in whilst the car is running. Then connect up the air intake system back up.

I find this usually make a huge difference.

hey thanks, the car it carby anyway so i assume i could just do the same but with the carb?

Jebus · Post by **Jebus** » Sun Dec 18, 2005 10:08 am

Yep take all the air filter assembly off, spray it all round the carb and rev it a bit when you spray it, itll blow white shit out of the exhaust, just wait till it burns it all away.

But first id change ya plugs etc first.

Volatile · Post by **Volatile** » Sun Dec 18, 2005 11:51 am

Jebus wrote:Yep take all the air filter assembly off, spray it all round the carb and rev it a bit when you spray it, itll blow white sh*t out of the exhaust, just wait till it burns it all away.

But first id change ya plugs etc first.

Cheers,

I've pulled the plugs out they seem all good. Is there anyway of testing leads?

I'm convinced it's fuel related as it only miss's just after 2500rpm and then pulls as normal after 3500rpm

BZG Wagon · Post by **BZG Wagon** » Sun Dec 18, 2005 12:13 pm

Volatile wrote:
Jebus wrote:Yep take all the air filter assembly off, spray it all round the carb and rev it a bit when you spray it, itll blow white sh*t out of the exhaust, just wait till it burns it all away.

But first id change ya plugs etc first.

Cheers,

I've pulled the plugs out they seem all good. Is there anyway of testing leads?

I'm convinced it's fuel related as it only miss's just after 2500rpm and then pulls as normal after 3500rpm

From memory, if you have a ohmeter or voltmeter you can check the resistance or voltage through the wire or something to that effect. Also look for signs of cracking at the end of the leads.

Ae92typeX · Post by **Ae92typeX** » Sun Dec 18, 2005 9:59 pm

as long as you have not got more than about 20,000 ohm resistance they should be ok. 8-14k is pretty normal.

Volatile · Post by **Volatile** » Mon Dec 19, 2005 7:07 pm

well i bought some CRC carb cleaner and it seems to have done the tick - Magic stuff