Thunderbird2 & Turbo Coupes

[scotty2]

Update.
Coil pack made no difference. Plugs - no difference. Leads - no difference.

Fuse contacts to the LPG system did look a bit corroded so sanded back to shiny and worked in and out the holder to ensure good contact as advised by the LPG support forum.
Misfire stopped and system switched over to gas when temp got above 30C and it has been OK over the weekend. I'm buggered if I can work out why it would misfire on petrol when not selected to run on LPG?? Unless it is still an intermittent fault that will return.
We will keep an eye on it.

[scoobyh123]

Update.
Coil pack made no difference. Plugs - no difference. Leads - no difference.

Fuse contacts to the LPG system did look a bit corroded so sanded back to shiny and worked in and out the holder to ensure good contact as advised by the LPG support forum.
Misfire stopped and system switched over to gas when temp got above 30C and it has been OK over the weekend. I'm buggered if I can work out why it would misfire on petrol when not selected to run on LPG?? Unless it is still an intermittent fault that will return.
We will keep an eye on it.

Glad to hear your LPG is working as it should again Scott, it is indeed a puzzle about the cold misfire!

[scotty2]

One of the guys on the LPG forum says that if the LPG ECU isn't getting power it can affect the running of the car on petrol. Who'd have thunk it !

[scoobyh123]

One of the guys on the LPG forum says that if the LPG ECU isn't getting power it can affect the running of the car on petrol. Who'd have thunk it !

Anyone in particular suggesting that? Electrically it shouldn't happen though.

[scotty2]

TB2 Update: Bottom balljoint rubber had split and let in water. Described as "rusted to buggery" by local garage. Arm off and heat applied to get it out apparently. Glad I didn't try and change it. (tripped and fell in the dark on my drive after thumping shin on TGMs tow bar and landed on our Dacia's tow bar with my ribs. Much pain in ribs not aided by a cold where sneezing and coughing has become like being stabbed! A week on and it is still bloody sore!).
TGM: LPG still working. No misfires, but the lambda sensor is needing nipped up as there is a bit of a leak that I found while checking out the LPG system.

[scoobyh123]

Blimey, the Attack of the Killer Zombie Towbars!

Hope you're recovering but ribs take a long time to recover, many moons ago i fell off the sofa reaching for the TV remote which i had dropped on the floor. Never known exactly what i did to my ribs (suspect pulled/torn muscle and/or bruised/cracked ribs) but even now, 22+ years on, catch them the wrong way and jeeeeeeeeeeezzz, it flippin' hurts!

Glad to hear the cars are behaving themselves at least, with the exception of the Zombie Towbars of course!

[scotty2]

Website disappeared for a few days so here is latest update!
TGM: LPG not staying active. Misfire when on petrol has returned. Does a strange kangaroo thing when on part throttle so when in a 30 zone it has the feeling of on/off throttle but when you accelerate it picks up, so OK at high load. trying to go smoothly at low speed brings back the kangaroo effect. No errors found in LPG ECU. When reset, it works for a few miles then goes back to flicking in and out. Might do a compression test in case of HGF as it does use a little water with no sign of leaks. Beginning to really bug me now!

TB2: Wifey stuck in traffic today and the temp went into the red. She noticed and pulled over to let it cool (brownie points!).
I tried to check the fan by unplugging the connector from the temp switch in the thermostat housing (top one seems to be for the fan, bottom one for the gauge) and shorting but no joy. Tried a direct feed to the fan and it wouldn't run. Made sure it was hot as it was during other tests (needle over half way and rising) then pulled the temp switch from the housing and the fan kicked in! Plugged it back in to the housing and the fan stopped. Pulled it and the fan started again!
I'm hoping it's some resistor driven logic and it will just be the temp switch, so I'll borrow one from one of the coupes to try that. All my other cars will start the fan if you short the temp switch, but this one confused me.

Happy New Year to all our readers...

[scoobyh123]

TGM - sounds suspiciously like the throttle pot Scott, only a few quid on ebay as they are the same as Sierra (Mondeo?) units. Near enough plug'n'play but you could check the voltage from it, should be about 0.7V WRT earth from the wiper and rising towards ~5V as it gets to WOT position - some only reach 4V but you can probably check whether it's working using the LPG software as i think that has a throttle pot voltage display.

The tell-tale will be if the voltage dispaears, especially at the point where you've been experiencing problems.

TB2 - what year is the car? Should be 2 fan switches, bottom is the low temp which will bring the fans on slow speed, second switches them both the fast, from what you've said it sounds like your twin relay for the fans. The twin relay is operated by the fan switches in the rad to change speeds and bring fans on in the first place.





Throttle pot replacement and single cooling fan circuit, i'll try and find the twin fans later.

[scotty2]

Cheers Dave. I think it could be TPS too. One ordered.

TB2 is a 1997 with no AC and only a single fan. I'll borrow a sensor from one of the Coupes to see if it is at fault.

[scoobyh123]

Cheers Dave. I think it could be TPS too. One ordered.

TB2 is a 1997 with no AC and only a single fan. I'll borrow a sensor from one of the Coupes to see if it is at fault.

On many 1996 on cars, the fan is controlled by the fuel ECU, i'm wondering if that one has been converted to the previous (reliable) system. If so, it should be a fairly simple fix, use the lower of the two fan switches from the rad in the spare coupes, assuming they're not 96 on as well. Shame you have no AC as you could have used that to force the cooling fan on.

[scotty2]

Well the new two pin temp sensor pinched from the Coupe and fitted to TB2 has cured the fan not cutting in so that's one sorted for now.

On TGM a new TPS has made no difference. It seems to be using a bit of water and I'm now thinking potential HGF. LPG still playing up.

[scoobyh123]

Well the new two pin temp sensor pinched from the Coupe and fitted to TB2 has cured the fan not cutting in so that's one sorted for now.

On TGM a new TPS has made no difference. It seems to be using a bit of water and I'm now thinking potential HGF. LPG still playing up.

Good news on the fan switch Scott, nice easy fix!

As for TGM, i'm thinking water pump. They have a tendency to leak from the back, where it can't be seen and pull air in creating airlocks (an airlock in the LPG reducer would result in under-temperature so the LPG would cut out) and eventually venting through the expansion tank - if it vents as vapour, no trace is likely to be found. A compression test would rule out (or in) HGF but i suspect it's more likely water pump causing the problem.
Also the fact airlocks are likely t be present would alter the temperature of the CTS in the head/'stat housing alternig the mixture causing potential misfires, particularly on light load.

I'd suggest deliberately overfilling the cooling system and taking it for a run, if it behaves for a while but then starts playing up when the level drops, i'd definitely be looking at the water pump.

[scotty2]

Forum was offline for a while?
TGM: By pulling and replacing the fuse again, the LPG has started working again. The poor running at part throttle after warming up is still there. Same when on gas or on petrol.
When started from cold, it runs fine. when it starts to warm up, it switches to gas as it should. When warmed up, it then has a rough idle with poor emissions (rich smell of fuel in the exhaust) and only runs OK when on mid to high throttle position. Trying to drive through the village at 20-30 mph, it "kangeroos" with rough running, and when you put the foot down, it picks up and runs ok until you return to low load.
I suppose the last thing to try will be Throttle body or air flow sensor? No water leak observed around the pump.
Can live sensor data be read from the diagnostic port?

[scoobyh123]

You should be able to read the live data on the LPG and at least some data on the petrol running Scott, there's no MAF on the T series but there is a MAP sensor built into the ECU - not sure if you'll be able to read that on the live data though.
Could be the rubber gasket is separaating from the throttle body on the inlet side causing a minor air leak, trying to move it with the engine off might reveal the fault there.

[scotty2]

Update:
TGM still playing up. Went in for a diagnostic check at the local garage who could not diagnose what was (is) wrong. LPG now stopped working as well! Think it is the tank solenoid as it doesn't click when LPG is selected. This was sorted a couple of years ago and seems like the solenoid has failed.
TGM had developed a squeak so it went in for a lower ball joint replacement and a CV boot while at it. A broken spring was found too. Luckily I had a pair of springs in stock (Vitesse Spec). The garage fitted the O/S one so I had an afternoon changing the other side and fitting a top ball joint to the O/S as it was identified as U/S by the garage.
The misfire/running rich is frustrating as we are not getting anywhere. I'll post the emissions findings when I get the bill.

TB2: All OK. Shh!