TVR s2 running very rich with backfire on tickover
Discussion
I still have a problem with my TVR s2 2.9 efi
All started with poor starting and misfiring, I changed leads ,Distributor cap,plugs ,coil.
Then it started easy but was running very rich, the new plugs sooted up very quick so bad that the spark was very weak. so l fitted another new set of plugs, again started easy then running with a backfire and still running rich.
Changed all injectors for new ones from e bay.
Same problem running rich, backfire on tick over slowly getting worse.
Fitted another ignition module, and it's still the same. The only thing l am not sure about is the injector electrical connections, do they need to be in a firing order , I had a old one and opened it up to find that three brown wires are joined together and the other three go in the other direction all joined together.
If anyone has a spare connector that has the cylinders numbered l would be willing to purchase it but it must have the round plug (not the oval one)
I am now thinking of buying a gasket set and changing the inlet gasket etc. any ideas would be great before l start to dismantle .
All started with poor starting and misfiring, I changed leads ,Distributor cap,plugs ,coil.
Then it started easy but was running very rich, the new plugs sooted up very quick so bad that the spark was very weak. so l fitted another new set of plugs, again started easy then running with a backfire and still running rich.
Changed all injectors for new ones from e bay.
Same problem running rich, backfire on tick over slowly getting worse.
Fitted another ignition module, and it's still the same. The only thing l am not sure about is the injector electrical connections, do they need to be in a firing order , I had a old one and opened it up to find that three brown wires are joined together and the other three go in the other direction all joined together.
If anyone has a spare connector that has the cylinders numbered l would be willing to purchase it but it must have the round plug (not the oval one)
I am now thinking of buying a gasket set and changing the inlet gasket etc. any ideas would be great before l start to dismantle .
Gerry
I had a word with the previous owner of your car today (not the owner you bought it from, the one before that) He says that the fuel pressure regulator was renewed for a standard one about 2 years ago, the injector loom and plug are standard (or at least, were on the car 8 years ago) and he had also renewed the coolant sensor. He says that the car was running fine then though, this was just ongoing maintenance.
I am no closer to figuring out what the problem is though - excess fuel pressure could be the answer, but I don't know how that can possibly relate to the problem we had, with the engine dying as the fan goes off.
I am starting to suspect that, even if the coolant temp sensor is ok, the ecu is still getting an incorrect signal, and thinks the engine is cold so is over-fualling. I know you've changed the ecu temporarily, but what if it was the wiring or the loom plug?
I had a word with the previous owner of your car today (not the owner you bought it from, the one before that) He says that the fuel pressure regulator was renewed for a standard one about 2 years ago, the injector loom and plug are standard (or at least, were on the car 8 years ago) and he had also renewed the coolant sensor. He says that the car was running fine then though, this was just ongoing maintenance.
I am no closer to figuring out what the problem is though - excess fuel pressure could be the answer, but I don't know how that can possibly relate to the problem we had, with the engine dying as the fan goes off.
I am starting to suspect that, even if the coolant temp sensor is ok, the ecu is still getting an incorrect signal, and thinks the engine is cold so is over-fualling. I know you've changed the ecu temporarily, but what if it was the wiring or the loom plug?
tvrgit said:
Gerry
I had a word with the previous owner of your car today (not the owner you bought it from, the one before that) He says that the fuel pressure regulator was renewed for a standard one about 2 years ago, the injector loom and plug are standard (or at least, were on the car 8 years ago) and he had also renewed the coolant sensor. He says that the car was running fine then though, this was just ongoing maintenance.
I am no closer to figuring out what the problem is though - excess fuel pressure could be the answer, but I don't know how that can possibly relate to the problem we had, with the engine dying as the fan goes off.
I am starting to suspect that, even if the coolant temp sensor is ok, the ecu is still getting an incorrect signal, and thinks the engine is cold so is over-fualling. I know you've changed the ecu temporarily, but what if it was the wiring or the loom plug?
Hi thanks for that information,I had a word with the previous owner of your car today (not the owner you bought it from, the one before that) He says that the fuel pressure regulator was renewed for a standard one about 2 years ago, the injector loom and plug are standard (or at least, were on the car 8 years ago) and he had also renewed the coolant sensor. He says that the car was running fine then though, this was just ongoing maintenance.
I am no closer to figuring out what the problem is though - excess fuel pressure could be the answer, but I don't know how that can possibly relate to the problem we had, with the engine dying as the fan goes off.
I am starting to suspect that, even if the coolant temp sensor is ok, the ecu is still getting an incorrect signal, and thinks the engine is cold so is over-fualling. I know you've changed the ecu temporarily, but what if it was the wiring or the loom plug?
I replaced the temp switch, and it seems to start and run at about 1800 rpm then after about 30 seconds its sits at 1,000 rpm, then it gets very lumpy and start to back fire through the exhaust on tick over. al this is a bit different from the time you were in my garage.
I have fitted another ignition module,no change .
I think it is over fuelling , l don't know how to tell any thoughts.If this doesn't work l will buy a full gasket set and replace the inlet manifold gasket and the air chamber gaskets.
I also think the connector to the electronic ignition may be suspect as l noticed a few small nick on the wire near the connector.What do you think.?
Gerry Mc said:
Was if back firing on tick over .
Yes, and the exhaust tips were black with soot eventually. Is there a garage near you can trust to test the fuel pressure for you? There are several things you need to rule out, excess fuel is one of them. According to PH you're less than 5 miles from me, if you need the name of a trustworthy reasonably priced garage, just let me know.
Gerry Mc said:
I think it is over fuelling , l don't know how to tell any thoughts...
How about a colourtune? You can see the colour of the burn a nd you'd get some idea if it was too rich. I've got one which is... erm... 33 years old!Gerry Mc said:
I also think the connector to the electronic ignition may be suspect as l noticed a few small nick on the wire near the connector.What do you think.?
I think that insulation of even the LT side of the ignition is very important, especially on electronic system that are detecting a magnetic pulse. can you try rubber solution or that brush-on insulation you can get?Edited by tvrgit on Sunday 6th November 21:04
Angelus said:
Yes, and the exhaust tips were black with soot eventually. Is there a garage near you can trust to test the fuel pressure for you? There are several things you need to rule out, excess fuel is one of them. According to PH you're less than 5 miles from me, if you need the name of a trustworthy reasonably priced garage, just let me know.
Hi I would like someone to have a look,only problem its now on a sorn and the MOT is up. As soon as l get it running it will be MOT d .If its snowing l will still be going for a MOT, I have missed out this year by not being able to use it.tvrgit said:
I think that insulation of even the LT side of the ignition is very important, especially on electronic system that are detecting a magnetic pulse. can you try rubber solution or that brush-on insulation you can get?
I would like to try anything to get this sorted . I would like a chat or if you are local call round , your help has been much appreciated.Gerry Mc said:
I would like to try anything to get this sorted . I would like a chat or if you are local call round , your help has been much appreciated.
I'm not sure I have been much of a help, I'm stumped too, but I have been trying to find out!I'm all over the place this week - how about Thursday afternoon?
The garage I was going to recommend was Carluke MOT Centre. They are a Merc' indy (but fix everything) and have a few technicians there who can help. PM me if you need the number of someone to take it there on a beaver tail. I would phone them first on 01555 751050 and talk to Alan. Tell them to MOT it once it is running. 
tvrgit said:
Gerry Mc said:
I would like to try anything to get this sorted . I would like a chat or if you are local call round , your help has been much appreciated.
I'm not sure I have been much of a help, I'm stumped too, but I have been trying to find out!I'm all over the place this week - how about Thursday afternoon?
Barkychoc said:
It sounds to me like the fuel injectors are permanently on or at least fuelling heavily - do you know anyone with an oscilloscope? If not put a bulb on one of the injector connectors and see if it flickers or stays on.
If it stays on you have your symptom but not the cause
Hi Thanks for that l will check this with a bulb tonight.If it stays on you have your symptom but not the cause
Cheers
hi hope i can help with your problem,i am new to the site having had the same problem with my car,which turned out to be the throttle pot was wired the oposite way around to it was on the wiring diragram,i corrected that and now it starts off at the turn of a key with no overfueling and smell of fuel when running,hope this helps you never know.
Gassing Station | S Series | Top of Page | What's New | My Stuff