Mazda MX5 Forum banner

Eunos Roadster Mk1 1.6 NA - injector seals replaced and the engine is a lot hotter

180 Views 13 Replies 3 Participants Last post by  GDCobra
Hi all,

Hope you're having a great Bank Hol.

'My baby' is an Eunos Roadster Mk1 1.6 NA.

Can I have some help please - one of the injectors developed a leak, the seals were replaced on all of them, the leak has stopped, but now she smells hot and after journeys when the engine is turned off the engine is hotter than normal and is still really hot to touch two hours later. Taking much longer to cool down. The water in the water resevoir is also getting hot. She's usually cold 30-60 mins after the engine is turned off. Am doing about 11-22 miles a day if am out atm. Longest trip has been to the garage approx 20 miles.

The coolant is correct, levels all good, the fan is working, sensors working, the temp gauge on the dash is less than half way. So have been told it's not the engine over heating as such and something is causing this.

We've also noticed when the key is in the 'on' position there is now an electrical / buzzing noise coming from the location framed in red in the photo - more to the right hand side, or it could be coming from underneath.

Could be coincidental timing ref changing the seals but this hasn't happened before. Any idea what is causing this please as will be good to get a permanent fix and have her back to normal? Don't like the idea of her being overly hot.

The mechanics have been amazing but she has flummoxed them and extra advice will be really appreciated. Am hoping it's a quick fix as not ready to part with her yet.

Having said the above she is driving fine, you wouldn't know there is an issue.

Thank you, Eunosfan
Motor vehicle Gas Automotive tire Automotive exterior Rim
See less See more
  • Like
Reactions: 1
1 - 6 of 14 Posts
Evening GDCobra,

Thank you for the reply.
The garage replaced the seals on the original injectors.
Some hoses, throttle valve, rail and injectors disassembled then reassembled. I don't know the names of all of the hoses but they were fuel ones. I could add photos?
The buzzing also only started after the seals were changed. It's quite high pitched. I can't hear over the engine if it continues to buzz when driving but my guess is yes.
This is a new noise. I've owned my car for 21 years and can tell every single change. The mechanics heard it as well but could not source it. If you put your head / ear down to the throttle valve, injectors, air hose, it's coming from that location.
This evening on start up she shuddered and then settled, no other issues and she drove fine.
Hope this helps.

Thank you, Jo
Hi GDCobra,

Thank you again, your replies are great I am learning every time 😊
My car is 1991.

Yes this is correct - my understanding is that this starts as soon as you turn on the ignition prior to actually starting the engine and continues until the engine starts

It was all four lower seals which were replaced and I think one o-ring.

I will have to wait until the weekend for time and daylight to check hoses and wires.

The ECUs were checked around the car and all ok.

Unfortunately my fan has now gone slow and I think this is related to the electrical noise? Very frustrating. Just stumbled on a couple of other forums and they mention the thottle body and it is in that area.
Could it be the PCV Valve / Pipe?
I will try using a screw driver to pinpoint the noise.

A few techy issues but will get photos added tomorrow.

Thank you again, Jo
See less See more
6
Evening GDCobra,

Thank you again. Am going back to the garage on Sunday, hoping this will be fixed. Will update you after.

Please see photos. Hope they help.

Have a great Bank Hol weekend.

Thank you for all of the help, Jo

Attachments

See less See more
2
Thank you GDCobra,

Your diagram is great thank you.
Some of the photos were taken while at the garage, and others parked up at home.
The AFM was tested and is ok, a 2nd hand one was connected for testing purposes and mine is fine.
The fan has packed up now and the electrical noise is quieter but still constant so I think it is related.
Hopefully will know more tomorrow.
The area framed is where I can hear the noise.
The hoses and wires in this area have been moved and bent a lot while the injectors were being worked on, this could be a potential reason?

Automotive tire Motor vehicle Automotive fuel system Electrical wiring Gas


Most of the hoses in the below have been disconnected several times

Vehicle Automotive fuel system Motor vehicle Automotive air manifold Car



Nice pic boxerdog1.

Hope these help, Jo
See less See more
Hi GDCobra,
Hope you had a great Bank Hol break.
Turned out to be the idle control valve.
As of Sat the CAT needs replacing as well.
So once these are done all should be good.
Thank you so much for your help.
Going to get the engine bay cleaned once everything is done, bit of TLC.
Kind regards, Jo
  • Like
Reactions: 4
1 - 6 of 14 Posts
Top