mx5cartalk.com

Hi all

Having issues with My Na6

Its a 1990 model, the car has been sitting around a lot lately and hasn't been dríven much. I took the car out for a 50k trip, the following day i changed the oil and the car ran fine, took it for a spin round the block a few times and it was running better than ever. The next day went to start the car and was idling rough and running on 3 cylinders. Does not like to rev and when you do rev it, it spits fuel out the exhaust and shakes the whole car. Checked for a spark from each plug each plug had a spark. Although after putting all the plugs back in cylinder 2 plug was wet with fuel. After i dried the plug and tried running it without the plug in it still sparked following this. This has me baffled. After this as a precaution i changed the coil pack the leads and plugs. To find I'm having the same issue still. So its safe to cancel out the ignition system being the cause for this issue. From my basic understanding it sounds like it may be a stuck valve or something similar. Because there is definitely fuel if its wetting the plug I'm guessing ? anyone had this issue or recommend a fix ?

I appreciate the help in advance.

Maybe a fuel injector is stuck fully open?

Hi.
Perhaps you may need a new set of spark plugs.

I have already replaced all the spark plugs and still having the same issue.

Im not sure how to check if my injector is stuck open.?

Think there's a method in the servicing manual about using a screw driver handle to the ear as a make-shift stethoscope to listen for a difference in sound (better if you have an actual stethoscope for automotive use).

Maybe move the 2nd fuel injector to one of the other cylinders & see if the cylinder wetting moves too? Though perhaps have some injector o-rings on hand in case the current (possibly original) ones break in the process.

Quick method is the screwdriver.

Start the car and place the screwdriver head on the injector, put your ear on the handle (works better with the hard handles, not so much with the rubber handled ones)

A working injector should be making a very rapid ticking sound, a stuck one will either be silent, or ticking at a different rate.

It's not a 100% test though, since these things can sometimes be intermittent.

Yea thats a good idea, never heard that one. Ill give it a try and see if i can hear any difference with the injector. thanks guys

So after some testing and playing around. I tried the screwdriver stethescope trick and sound like cylinder 1 and 3 are not firing and after removing the plugs they are socked in fuel. I can not hear the ticking from the injectors on 2 cylinders, I'd say injector 1 and 3 are jammed open.? But what is the coincidence of 2 injectors being jammed open. This issue is beginning to get beyond my set of skills. The problem is I can't get it to any mechanic

Has no one else run into this problem

Possibly the cas?

CAS stops the injectors firing as well as spark. If the plugs are wet then the CAS is at least firing the injectors. However testing a working CAS will eliminate it.

Another way to check the CAS/Injector is with a Noid light http://www.transquip.com.au/products/SP71050-SP-TOOLS-NOID-LIGHT-KIT-6PC.html

Have you done a compression test?

Have you checked the timing?

Are you in the Brisbane area as I have a tool similar to a noid light to test the injectors.

The Cas has got a significant oil leak coming from it, i have not checked the timing or the compression.
I will try the timing but i don't have the tools to test compression.
No I'm in sydney, I appreciate the offer tho.

Go the CAS and fix the oil leak up and then re test.

I have got a couple of CAS if you need one, maybe if you can borrow one and see if that fixes your problem, I'm in Perth though, try and see if you get one locally.
Terry
0418925005

Hey thanks for the offer Terry

I may have found the issue. The heater core has sprung a leak and filled my ECU with coolant so I'm guessing that
would have something to do with the problem. So hopefully if i replace the ECU that solves the problem.

Anyone got a cheap stock ECU for sale ?

got one of those as well:)