Eunos Roadster MK1 - heat sensor broke, loss of power since
Discussion
Hi all,
I am new to PistonHeads and need some help diagnosing an issue with my 'baby' please.
Eunos Roadster, Mk1, 1.6
A few weeks ago I was driving on a motorway and all of a sudden heard a loud banging under the car. I managed to pull over and could see a cable hanging down which was hitting the road and the underneath of the car.
Unfortunately due to the length of my drive the cable eventually came off as I couldn't reach it to tie it to hold, and it turns out it was the heat sensor, leaving a considerable hole in the CAT. Naturally my car drove like she was misfiring but I managed to get home.
I have spent the past two months driving on rubbish roads with major pot holes and think the sensor just rattled itself free.
Initially my garage welded the hole in the CAT and said the sensor wasn't needed as there is no warning light on the dash. But the car kept losing power, hot / cold running, low or fast speeds. This happens a few mins after starting the car or constantly while driving.
So the garage cut a new hole in the CAT and attached a lambda sensor. Same problem. A diagnostic tool was used and a 'short' fault was found with the air filter housing, so this was all replaced. Same problem. Another fault found and the water temperature sensor was replaced. Same problem. This is now a few weeks on, can't be good for the car, she is drinking petrol and costing me a small fortune trying to resolve.
My garage are great and trying to help with this but are somewhat stumped, they now think it's due to the ECU.
The problem is exactly the same from when the heat sensor first came off, so I'm convinced it's to do this with and not the ECU.
She massively over idles and then drops almost to the point of stalling, so long as I keep pumping the accelerator she'll keep going. But I really need this fixing as there have been a few hair raising moments where she just stops at any speed, and ie: on dual carriage ways etc.
The spark plugs have been changed and I'm going to put on new HT Leads.
I've been doing some research and have found drivers with similar problems but not identical. Changing camshaft and crank sensors have been mentioned but I don't want to just keep changing parts for the sake of it.
Can anyone please please help??
Thank you!
I am new to PistonHeads and need some help diagnosing an issue with my 'baby' please.
Eunos Roadster, Mk1, 1.6
A few weeks ago I was driving on a motorway and all of a sudden heard a loud banging under the car. I managed to pull over and could see a cable hanging down which was hitting the road and the underneath of the car.
Unfortunately due to the length of my drive the cable eventually came off as I couldn't reach it to tie it to hold, and it turns out it was the heat sensor, leaving a considerable hole in the CAT. Naturally my car drove like she was misfiring but I managed to get home.
I have spent the past two months driving on rubbish roads with major pot holes and think the sensor just rattled itself free.
Initially my garage welded the hole in the CAT and said the sensor wasn't needed as there is no warning light on the dash. But the car kept losing power, hot / cold running, low or fast speeds. This happens a few mins after starting the car or constantly while driving.
So the garage cut a new hole in the CAT and attached a lambda sensor. Same problem. A diagnostic tool was used and a 'short' fault was found with the air filter housing, so this was all replaced. Same problem. Another fault found and the water temperature sensor was replaced. Same problem. This is now a few weeks on, can't be good for the car, she is drinking petrol and costing me a small fortune trying to resolve.
My garage are great and trying to help with this but are somewhat stumped, they now think it's due to the ECU.
The problem is exactly the same from when the heat sensor first came off, so I'm convinced it's to do this with and not the ECU.
She massively over idles and then drops almost to the point of stalling, so long as I keep pumping the accelerator she'll keep going. But I really need this fixing as there have been a few hair raising moments where she just stops at any speed, and ie: on dual carriage ways etc.
The spark plugs have been changed and I'm going to put on new HT Leads.
I've been doing some research and have found drivers with similar problems but not identical. Changing camshaft and crank sensors have been mentioned but I don't want to just keep changing parts for the sake of it.
Can anyone please please help??
Thank you!
Hi JimSuperSix,
Thanx for the quick and helpful reply.
I've got her booked in to two different garages to see if they can work together to diagnose and resolve the issue.
The noise and how she is driving is exactly the same as when the heat sensor first came off, hence am not sure it's the ECU, but am more than happy for this to be eliminated. It's as if there is still a hole in the exhaust somewhere.
Am by no means an expert but have owned my baby for nearly 16 years so I know enough to get by and maintain and change the basics.
In my ignorance, if it was a heat sensor which was originally fitted and she was driving perfectly, but a lambda sensor is now fitted and she isn't, what is the difference?
Cheers eunosfan
Thanx for the quick and helpful reply.
I've got her booked in to two different garages to see if they can work together to diagnose and resolve the issue.
The noise and how she is driving is exactly the same as when the heat sensor first came off, hence am not sure it's the ECU, but am more than happy for this to be eliminated. It's as if there is still a hole in the exhaust somewhere.
Am by no means an expert but have owned my baby for nearly 16 years so I know enough to get by and maintain and change the basics.
In my ignorance, if it was a heat sensor which was originally fitted and she was driving perfectly, but a lambda sensor is now fitted and she isn't, what is the difference?
Cheers eunosfan
Hi all,
So the CAT, spark plugs and HT Leads were replaced but she is still over idling like mad - I got about a mile down the road and she over idled and then dropped. They checked the ECU and it isn't that. Started her up again a few hours later, sat stationary in a car park and she over idled again.
I needed the N/S window regulator replacing but apparently the original switch wouldn't work with it, so they replaced the switch with one they had, but this meant they had to adapt the O/S too. A few miles down the road the switch stopped working and I couldn't wind the window back up, I just had to keep trying until it worked.
I had to drive to Northampton so a good run, and she was parked for about 3.5 hours, I got back in her to leave and turned the key and nothing, she was dead, but the lights and radio worked. I also noticed that the warning light for the rear heated windscreen was on on the dash, it has never come on in 16 years as I don't actually have one, and the switch for it was lit up permanently. I checked the battery cables and the basics under the bonnet, tried again and she fired up. Again she over idled and dropped back down.
The radio also stops working when I use the wipers...
As the garage worked on electrics today (Fri) is tonights problem anything to do with the work they've done? They can't have her back in until next week and I am so p'd off with what has happened.
Any ideas please?
Thanx Eunosfan
So the CAT, spark plugs and HT Leads were replaced but she is still over idling like mad - I got about a mile down the road and she over idled and then dropped. They checked the ECU and it isn't that. Started her up again a few hours later, sat stationary in a car park and she over idled again.
I needed the N/S window regulator replacing but apparently the original switch wouldn't work with it, so they replaced the switch with one they had, but this meant they had to adapt the O/S too. A few miles down the road the switch stopped working and I couldn't wind the window back up, I just had to keep trying until it worked.
I had to drive to Northampton so a good run, and she was parked for about 3.5 hours, I got back in her to leave and turned the key and nothing, she was dead, but the lights and radio worked. I also noticed that the warning light for the rear heated windscreen was on on the dash, it has never come on in 16 years as I don't actually have one, and the switch for it was lit up permanently. I checked the battery cables and the basics under the bonnet, tried again and she fired up. Again she over idled and dropped back down.
The radio also stops working when I use the wipers...
As the garage worked on electrics today (Fri) is tonights problem anything to do with the work they've done? They can't have her back in until next week and I am so p'd off with what has happened.
Any ideas please?
Thanx Eunosfan
Hi,
Thanx very much for the reply and help.
Yes a normal garage and they checked to see if it was wet.
I checked the battery cables last night and they seemed ok, albeit they didn't need to check the battery at all yesterday while working on electrics. They told me this after I commented on the heated rear windscreen lights because they said the relay for it is in the boot, with the battery, and they didn't need to go in the boot.
I will check everything again later.
She started again after checking the battery and checking the HT Leads, one of which was not on properly and I was advised it had 'popped' off earlier.
The idle issue, in fact all of these problems, have only started post the heat sensor coming off of the CAT, the work done on this, and the air filter housing and water temp sensor being changed by the garage.
The problems last night started after they replaced the window switch as my original switch wouldn't work with the new window regulator they replaced, which was the N/S. I am now having problems with the O/S as the replacement switch doesn't work properly and the window does / doesn't wind up or down.
Am so annoyed. I have her booked in to another garage next week who are also experienced with auto electrics.
Any other ideas in the meantime please?
Cheers Eunosfan
Thanx very much for the reply and help.
Yes a normal garage and they checked to see if it was wet.
I checked the battery cables last night and they seemed ok, albeit they didn't need to check the battery at all yesterday while working on electrics. They told me this after I commented on the heated rear windscreen lights because they said the relay for it is in the boot, with the battery, and they didn't need to go in the boot.
I will check everything again later.
She started again after checking the battery and checking the HT Leads, one of which was not on properly and I was advised it had 'popped' off earlier.
The idle issue, in fact all of these problems, have only started post the heat sensor coming off of the CAT, the work done on this, and the air filter housing and water temp sensor being changed by the garage.
The problems last night started after they replaced the window switch as my original switch wouldn't work with the new window regulator they replaced, which was the N/S. I am now having problems with the O/S as the replacement switch doesn't work properly and the window does / doesn't wind up or down.
Am so annoyed. I have her booked in to another garage next week who are also experienced with auto electrics.
Any other ideas in the meantime please?
Cheers Eunosfan
Evening,
So the problems with the electrics only started last night after the window switch was replaced. The regulator died on me weeks ago but I only got round to having it replaced yesterday. There was no problem with the O/S window until after the switch was replaced.
The N/S window regulator has been replaced twice now, and the O/S once, no problems with the switches.
The rear window defogger light has never ever come on on the dash before as I don't have one, and the switch for this has never stayed lit up before. I have a soft top with a plastic rear window.
When I got her started there was a high pitch shorting noise, this happened yesterday as well but I forgot to mention it, again post this switch being installed.
When the heat sensor initially broke off, this will have left cables dangling and disconnected under the car as the sensor was basically ripped off bouncing along hitting the road and car - how do I know this has all been fixed correctly with the new CAT and heat sensor? Where does the wiring go and what else might it be connected to?
I get most of my parts from Autolink who are brilliant, and they recommended the current garage and BBR. They also commented on getting the AFM checked as the air filter housing was changed. Thank you for the link.
Yes she has an immobliser and from what I can tell all is working correctly, and the light on the dash is working.
I've checked the under bonnet fuse box and that seems fine.
And tonight the same thing happened - parked up for a few hours, turned the key in the ingnition and nothing bar the heated rear windscreen light on the dash. I wiggled the battery connections and the relay in the boot for the rear heated windscreen and she started again, and the light went off of the dash.
I was sat in the car for a good 5/6 mins with the engine running and once again she started to over idle, the RPM goes up to 3/4000 and then fluctuates between 0-4000, I have to press the accelerator to stop her from doing this and she goes back to normal but upon pressing the accelerator she sounds as though she's misfiring or as if the exhaust still has a hole in it. Eventually this stops and the upside is she's not doing it all the time now.
As you can appreciate all very annoying. I think I'll have to wait until I can take her to BBR.
Cheers!
So the problems with the electrics only started last night after the window switch was replaced. The regulator died on me weeks ago but I only got round to having it replaced yesterday. There was no problem with the O/S window until after the switch was replaced.
The N/S window regulator has been replaced twice now, and the O/S once, no problems with the switches.
The rear window defogger light has never ever come on on the dash before as I don't have one, and the switch for this has never stayed lit up before. I have a soft top with a plastic rear window.
When I got her started there was a high pitch shorting noise, this happened yesterday as well but I forgot to mention it, again post this switch being installed.
When the heat sensor initially broke off, this will have left cables dangling and disconnected under the car as the sensor was basically ripped off bouncing along hitting the road and car - how do I know this has all been fixed correctly with the new CAT and heat sensor? Where does the wiring go and what else might it be connected to?
I get most of my parts from Autolink who are brilliant, and they recommended the current garage and BBR. They also commented on getting the AFM checked as the air filter housing was changed. Thank you for the link.
Yes she has an immobliser and from what I can tell all is working correctly, and the light on the dash is working.
I've checked the under bonnet fuse box and that seems fine.
And tonight the same thing happened - parked up for a few hours, turned the key in the ingnition and nothing bar the heated rear windscreen light on the dash. I wiggled the battery connections and the relay in the boot for the rear heated windscreen and she started again, and the light went off of the dash.
I was sat in the car for a good 5/6 mins with the engine running and once again she started to over idle, the RPM goes up to 3/4000 and then fluctuates between 0-4000, I have to press the accelerator to stop her from doing this and she goes back to normal but upon pressing the accelerator she sounds as though she's misfiring or as if the exhaust still has a hole in it. Eventually this stops and the upside is she's not doing it all the time now.
As you can appreciate all very annoying. I think I'll have to wait until I can take her to BBR.
Cheers!
Hi all, so we went to BBR and they were great, very thorough. We found that the new CAT hadn't been put on correctly so the flanges / pipes didn't line up and only one bolt, which was the wrong size, had been forced in to one of the holes. As a result the exhaust was still leaking which is what I could hear and feel aiding to the ongoing problems. The wrong water temperature sensor had been replaced as this was still coming up as an error on the diagnostics. And an electrical connection was left shorting, can't remember which one now. The exhaust was corrected and now has two bolts sealing the pipes. The ECU and coil pack were thoroughly checked and tested, including footwell area, and reset, no further fault codes found. Correct water temperature sensor replaced. The battery was reset. Centre console removed and the windows and window switch were corrected. They even fixed my O/S door panel speaker which had been left hanging by previous garages ;-) Agreed to see how she goes and report back with any issues. So am very happy to report that the over idling and loss of power is resolved, yay so pleased! Unfortunately on low idle she has almost stalled a few times and the 'shorting' is still happening when I turn the key and start the engine. As of Sunday when I put my foot down on the accelerator there is a high pitch coming from the exhaust, and it sounds as though there is movement, as well as the gear stick vibrating and the car slightly shuddering, which I can't feel via the steering wheel. Then as of today the anti lock warning light came on and what I think is the ABS pump stays on even after the engine is turned off and the key removed. The unit gets hotter and noisier the longer it is on so some helpful colleagues showed me how to disconnect it while I'm not driving. BBR informed and my pride and joy is going back to them tomorrow. I have no idea if this is related to any of the works done regarding the ECU, sensors and electrics or just a coincidence, but so flippin' annoying - anyone? Cheers
Thanx for the replies and support again. Yes hopefully I will have some good news tomorrow. The electrics is one thing I won't touch so the garages have dealt with that - can't believe all of the combined problems! 
The issues the past few weeks have been the most I've ever had in the 16 years I've owned her, prior to this she ran perfectly. I just want her back to normal. Does anyone know if any of these latest issues are linked to the problems / works done recently?
The issues the past few weeks have been the most I've ever had in the 16 years I've owned her, prior to this she ran perfectly. I just want her back to normal. Does anyone know if any of these latest issues are linked to the problems / works done recently?Hi all, so the saga continues and am really fed up now. Am going to refer to both as garage 1 and garage 2 from now on. Collected my baby on Friday and was advised it was the ABS relay and that she had been taken for dirves along very bumpy roads and over pot holes to try and replicate the issue and dislodge the ABS pump / relay and coudn't, asked to be shown said relay so I know what to do and as the bonnet was raised I noticed #1 HT lead wasn't even connected to the spark plug, it was sitting about an inch above the cylinder head. This was pushed back in. Unfortunately garage 2 had no time to do the other works and I carried on my merry way. A bit of 'fluffing' as I like to call it and made it home ok. Garage 1 commented on the #1 HT lead not seating correctly so I'd already ordered another, albeit was a brand new set, however I was not told this until I commented that I'd found it like it when they were initially helping with issues. Replacement HT lead arrived on Sat and I swapped this out quickly before heading off again pushing it down very firmly. There was no movement, it was connected, but I didn't hear or feel any click in to place. Drove approx 20 miles, sat stationary at traffic lights and the flippin' over idling started again. Got to my destination but too dark to be able to check properly, a bit of fluffing again and made it home ok. Finally had the opportunity to check things over in daylight, HT leads 3 & 2 were the wrong way round in the coil pack. switched these around and finally got #1 lead to click on the spark plug, started her up and she happily idled at approx 800 RPM. Left her like this for a while and turned her off / on a few times and ok. Could still hear a bit of fluffing and when I covered the exhaust tail pipe she's farting like a trooper. I've read the leads can be switched and one on each coil pack is 'wasted', but all of this has caused so many problems the past few weeks. Both garages have now worked on the exhaust, sensors, ECU, electrics, spark plugs, HT leads, coil pack, window regulators and switches, air filter and housing - noticed this has holes in it - ABS pump and relay, I have never had so many issues, am I barking up the wrong tree or is some of this related to ongoing issues?? I feel as though I've been fobbed off and am not expected to notice certain things. I've spend good money after bad and am not getting anywhere. This has all stemmed from the original issue of the heat sensor breaking away from the CAT. I just want someone to sort this out and not stitch me up. Look foward to hearing from you.
Hi all, so the saga continues and am really fed up now. Am going to refer to both as garage 1 and garage 2 from now on. Collected my baby on Friday and was advised it was the ABS relay and that she had been taken for dirves along very bumpy roads and over pot holes to try and replicate the issue and dislodge the ABS pump / relay and coudn't, asked to be shown said relay so I know what to do and as the bonnet was raised I noticed #1 HT lead wasn't even connected to the spark plug, it was sitting about an inch above the cylinder head. This was pushed back in. Unfortunately garage 2 had no time to do the other works and I carried on my merry way. A bit of 'fluffing' as I like to call it and made it home ok. Garage 1 commented on the #1 HT lead not seating correctly so I'd already ordered another, albeit was a brand new set, however I was not told this until I commented that I'd found it like it when they were initially helping with issues. Replacement HT lead arrived on Sat and I swapped this out quickly before heading off again pushing it down very firmly. There was no movement, it was connected, but I didn't hear or feel any click in to place. Drove approx 20 miles, sat stationary at traffic lights and the flippin' over idling started again. Got to my destination but too dark to be able to check properly, a bit of fluffing again and made it home ok. Finally had the opportunity to check things over in daylight, HT leads 3 & 2 were the wrong way round in the coil pack. switched these around and finally got #1 lead to click on the spark plug, started her up and she happily idled at approx 800 RPM. Left her like this for a while and turned her off / on a few times and ok. Could still hear a bit of fluffing and when I covered the exhaust tail pipe she's farting like a trooper. I've read the leads can be switched and one on each coil pack is 'wasted', but all of this has caused so many problems the past few weeks. Both garages have now worked on the exhaust, sensors, ECU, electrics, spark plugs, HT leads, coil pack, window regulators and switches, air filter and housing - noticed this has holes in it - ABS pump and relay, I have never had so many issues, am I barking up the wrong tree or is some of this related to ongoing issues?? I feel as though I've been fobbed off and am not expected to notice certain things. I've spend good money after bad and am not getting anywhere. This has all stemmed from the original issue of the heat sensor breaking away from the CAT. I just want someone to sort this out and not stitch me up. Look foward to hearing from you.
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