Intermittent Misfire

[halvorlu]

My Toyota Carina E 1997 with an 7A-FE engine has recently started misfiring and running on 3 or even 2 cylinders (from the sound/feel of it). This only happens when the engine is warmed up, and it can go on for anything from a few seconds to a few minutes, and then suddenly disappear again, so the engine once again runs smoothly. It then comes back after a few seconds or minutes. It seems to happen at any engine speeds, even at idle.

I've already changed spark plugs, which didn't help. The fuel filter was changed 40 000 km ago, maybe even later. Are there any components that I should check which could cause these problems?

Thanks in advance.

[Red Yaris 54]

Moved to Carina Forum

[garethpaul]

could be a faulty/sticking injector.

Good tip to find out is grab a long screwdriver with a fat handle, and hold the tip of the screwdriver on the injector body when the engine is idling and place your ear on the handle.

Every time the injector fires, you will hear a regular "tick" through the screwdriver handle, much like an old windup clock.

Do this when it's misfiring and you can tell if an injector is not "ticking", and therefore not working.

[martyp11]

yes i agree with gareth paul ,i had the same thing exactly .check with ometer on the injector terminals take off eleky connector put red on one black on the other check resistance from w.manual. do this on all injectors.

[PGPrem]

My Toyota Carina E 1997 with an 7A-FE engine has recently started misfiring and running on 3 or even 2 cylinders (from the sound/feel of it). This only happens when the engine is warmed up, and it can go on for anything from a few seconds to a few minutes, and then suddenly disappear again, so the engine once again runs smoothly. It then comes back after a few seconds or minutes. It seems to happen at any engine speeds, even at idle.

I've already changed spark plugs, which didn't help. The fuel filter was changed 40 000 km ago, maybe even later. Are there any components that I should check which could cause these problems?

Thanks in advance.

My car is year 2000, the same problem having in my car too, injectors cleaned, but problem is pending, could you help me?

[halvorlu]

My problem turned out to be the fuel injector on cylinder number 3, which seems to be a very common problem for this engine! Changed it and everything was fine again. It can be diagnosed by listening to the fuel injectors while the misfiring is going on, for example using a screwdriver that you hold between your ear and the fuel injector. I think you can find more comprehensive answers elsewhere on this forum if you search a bit.

[00833827]

well done - I had the same on mine - replaced fuel injector did the trick

[Harry Carri]

Hi,

I agree with previous posts suggesting a dying injector. I had the same symptoms with mine.

I did not know about the screwdriver test so once the car was running unevenly ( usually when fully warmed up) I removed the electrical supply plugs to the injectors one at a time with the engine running, three of them when removed made the engine run more unevenly ( only 2 injectors delivering fuel) one made no difference so that was the faulty one.

Injector cleaner kept the symptoms away initially so if you have a long and important journey to do before you can change the injector that may help.

I put a new injector in mine with the help of a workshop manual and socket set in approx 2 to 3 hrs working slowly and carefully (with plenty of tea) as I am no expert mechanic and I had not done a similar job on a car before.

I chose to buy a new injector (90 quid if I remember rightly but was about 4 years ago) as their life is suggested to be between 100,000 and 150,000 miles and Carina e and early Avensis with 7AFE being broken typically had that sort of mileage on them.

I found some posts on here about injector failure which helped me diagnose mine.

Hope that helps.

Matt

[giogio]

Hello everybody,

I also need to change my injectors... any experiences with chinese ones on alibaba.com?

Regular ones cost €250+ here in Italy, while there about $25 is enough...

gio

[wildside]

Hi, I've been having the same problem on mine. Having changed leads, distributor cap, and swapped over injectors I finally checked the in tank fuel pump only to find it didn't run unless I put a direct feed to it from the Battery which leads me to believe it's the fuel pump relay switch at fault, however I cannot locate the relay so I bypassed it and fingers crossed all seems fine. However it's not the ideal solution because the pump is running all the time (not good in an accident). If you or anybody else knows where the relay is sited I would love to know so that I can replace it.