New C3 owner, already bad news!!
Discussion
Hello all,
I was hoping to arrive on here today and tell you all how chuffed I was that I'd got myself a C3 that I'd been wanting for ages and how brilliant it was.
Unfortunately not 12 hours after buying it I'm already having issues. On the drive back from buying it yesterday all was fine until the end of the journey. But I'll give you a quick history first:
- '77 C3 with a new engine this may (brand new crate engine), EB Supercharger, new radiator, replaced longer ratio diff etc etc.
- Went for test drive on Monday. All was well.
- Bought on tuesday, started from cold first time, and after letting it warm up on the sellers drive, drove back to my house 90 miles away, through bad traffic and also open motorway. No issues, car ran fine.
- End of motorway, coming into my town at home, I came off the throttle and the excess fuel in the system backfired through the supercharger (the seller warned me to always keep revs up in order to avoid this, dropping into lower gear for roundabouts etc, which I did do). Carried on ok, but then a mile from home turned up a hill and again had a backfire and stalled. Restarted and just managed to get home, with one more stall just before I got back.
- Once back and safe, tried restarting, which it does fine, but as soon as I come off the throttle and its returns to idle revs it cuts out. If it was cold this would have been understandable, but this was at the end of a long journey and the engine was more than warm.
- Tried again this morning but the same problem is happening, often with a loud pop out of the SC when revs are dropped and excess fuel explodes.
As you can probably imagine I'm fairly upset about this. I want to give the seller the benefit of the doubt as he seemed a geniune guy and had obviously spent a great deal getting the car to where it is with new engine etc.
Anyone got any idea what my be causing the issue? I can't drive it now as it won't idle at all, so I can't even get it into gear before it cuts out. I'm guessing its a fuelling or carb problem of some sort, but I'm not overly mechanically minded.
Any help would be massively appriciated!
Voguely.
I was hoping to arrive on here today and tell you all how chuffed I was that I'd got myself a C3 that I'd been wanting for ages and how brilliant it was.
Unfortunately not 12 hours after buying it I'm already having issues. On the drive back from buying it yesterday all was fine until the end of the journey. But I'll give you a quick history first:
- '77 C3 with a new engine this may (brand new crate engine), EB Supercharger, new radiator, replaced longer ratio diff etc etc.
- Went for test drive on Monday. All was well.
- Bought on tuesday, started from cold first time, and after letting it warm up on the sellers drive, drove back to my house 90 miles away, through bad traffic and also open motorway. No issues, car ran fine.
- End of motorway, coming into my town at home, I came off the throttle and the excess fuel in the system backfired through the supercharger (the seller warned me to always keep revs up in order to avoid this, dropping into lower gear for roundabouts etc, which I did do). Carried on ok, but then a mile from home turned up a hill and again had a backfire and stalled. Restarted and just managed to get home, with one more stall just before I got back.
- Once back and safe, tried restarting, which it does fine, but as soon as I come off the throttle and its returns to idle revs it cuts out. If it was cold this would have been understandable, but this was at the end of a long journey and the engine was more than warm.
- Tried again this morning but the same problem is happening, often with a loud pop out of the SC when revs are dropped and excess fuel explodes.
As you can probably imagine I'm fairly upset about this. I want to give the seller the benefit of the doubt as he seemed a geniune guy and had obviously spent a great deal getting the car to where it is with new engine etc.
Anyone got any idea what my be causing the issue? I can't drive it now as it won't idle at all, so I can't even get it into gear before it cuts out. I'm guessing its a fuelling or carb problem of some sort, but I'm not overly mechanically minded.
Any help would be massively appriciated!
Voguely.
Driving it straight back would be great - if I was able to drive it anywhere!
As for getting rid of the SC - possibly a better idea, which I'd already considered. Hopefully I'd be able to sell the SC 2nd hand for enough to cover any other parts to put it back to normal too, although it would need a new bonnet without a hole in the middle too!
I'll have a look for vaccum pipes, cheers.
As for getting rid of the SC - possibly a better idea, which I'd already considered. Hopefully I'd be able to sell the SC 2nd hand for enough to cover any other parts to put it back to normal too, although it would need a new bonnet without a hole in the middle too!
I'll have a look for vaccum pipes, cheers.
roscobbc said:
Firstly what blower is being used - is it blow through? is it a Gimmy style draw through blower (mounted on top of inlet manifold with carb on top) - is it carbed? - what carb is it? - if a Holley (or derivative) backfires will rupture power valve in carb and cock-up running. You don't want a Vette specialist - a specialist in Yanky engines with experience in blowers would be more useful. What past of Essex are you? - its Essex Vette club meet tonight at Red Lion Margaretting - come talk to us - Rdgs, Ross
Ross,Thanks for the kind offer of joining you - I may well do so in future when I've got a working car! My main car is down in Hampshire at the moment, so I can't even come in that! I'm in Colchester, you?
It is indeed a holley carb, mounted on top of the SC which is on top of the engine. (intake is out of the bonnet). SC is an Edelbrock.
When I spoke to the guy at Corvette Kingdom up in Norfolk earlier he said himself that he thought it could have been the valve damaged by the SC backfire, so you may well be right.
Do you know anyone around this area who is a yank engine specialist by chance? Who do you use to look after yours, or are you mechanically minded enough to maintain it yourself?
To previous poster - yes, I called the seller, he knew that it backfired if revs were dropped too quickly then back on the throttle again - for example coming upto a roundabout in too high a gear, but said he hadn't had any issues like I'm having. It is quite difficult to keep the revs up though in this, being an automatic manual, even taking it down into first on approach to junctions it still seemed to be collecting too much unburn fuel and causing these backfires. Maybe the fuelling needs to be adjusted down.
I'm really hoping I can get this fixed and it isn't anything too horrendous, its such a beautiful car otherwise!
roscobbc said:
I can suggest Terry or Andy of T & A motors who have respectively have workshops in Billericay and Basildon. They have been involved with Vettes and yank powered stuff for 30 plus years and may be able to help you - although as I said earlier this is not a Vette specific problem - Andy is on 01268 590891. The problem with these type of blowers is exactly the one you are experiencing i.e. excess fuel puddling in the blower casing if the carb isn't set-up correctly. It sounds as though you may have an issue with the ignition timing too causing the backfires.
Thanks again, although just called Andy and he said that he's retired now which is a shame (for me, good for him obviously, ha!)Edited by roscobbc on Wednesday 19th September 23:02
Thanks for all the replies guys, much appriciated. Seems there are a few American motor types hiding in various places not too far away from me! Hopefully if it is a blown valve in the carb then it can be fixed without costing the earth and then with a bit of timing/fuelling tuning it won't do it again and I'll be on the road once more!
p.s. James, that's a lovely C3 you've got in your profile! Are you around this area too?
p.s. James, that's a lovely C3 you've got in your profile! Are you around this area too?
Edited by Voguely on Thursday 20th September 20:07
Well finally back from my jollies and got a new battery for the 'vette and had someone come look at it today. Wasn't starting to begin with until the guy put his finger over some kind of intake nozzle on the back of the supercharger, when it suddenly came to life. Seems that some kind of cover for this nozzle must have come off at some point, leading to air going straight into the SC bypassing the Carb and causing savage backfires. Although I'm not convinced that this is the only problem, but rather I reckon it has been exaggerated by this and that possibly the nozzle cover was only blown off by one of the later backfires (and that is when it stopped being able to idle).
Also the gasket between the engine and the supercharger had also broken (possibly as a result of the backfires) and so that is now also leaking air in. Bad times. Anyway the above problem is easily fixed with a bit of hose+bolt as a cover, but now I've got to try and find a gasket for an Edlebrock supercharger somewhere - had a quick look online and it's not looking easy so far, these things are rare!! So any advice is very welcome. I've tried looking for a serial number on the SC but couldn't see one. Its magnusson type long nose charger (I'll take a pic at some point and post it here).
Cheers!
edit - SC looks like this http://www.summitracing.com/parts/EDL-1551/?rtype=... however there are a number of sligghtly different models which all look very similar! I'll investigate more (unless someone can tell me if they all share the same base footprint and therefore gasket? (and where to get said gasket!?)
edit 2 - think I've found what I need! Hope so as shipping was double what the part cost! Oh the joys of classic american motoring!
Also the gasket between the engine and the supercharger had also broken (possibly as a result of the backfires) and so that is now also leaking air in. Bad times. Anyway the above problem is easily fixed with a bit of hose+bolt as a cover, but now I've got to try and find a gasket for an Edlebrock supercharger somewhere - had a quick look online and it's not looking easy so far, these things are rare!! So any advice is very welcome. I've tried looking for a serial number on the SC but couldn't see one. Its magnusson type long nose charger (I'll take a pic at some point and post it here).
Cheers!
edit - SC looks like this http://www.summitracing.com/parts/EDL-1551/?rtype=... however there are a number of sligghtly different models which all look very similar! I'll investigate more (unless someone can tell me if they all share the same base footprint and therefore gasket? (and where to get said gasket!?)
edit 2 - think I've found what I need! Hope so as shipping was double what the part cost! Oh the joys of classic american motoring!
Edited by Voguely on Monday 15th October 18:55
Edited by Voguely on Monday 15th October 21:03
Z28DUNC said:
What type of gasket is it? You might be able cut your own out of gasket material. I've done this for rocker gaskets before but not sure what material a supercharger gasket would be made out of.
Thanks for the tip - may look into this as an option. I've ordered a gasket for between the top of the engine and baseplate of the SC. But can't find one for the gasket between the baseplate of the SC and the SC main body, so making my own could be the way forward. I'll have to get the SC off and have a look what it's made from. Did your own home-cut ones work ok? Anyone else with an experience (good or bad) of creating their own gaskets?
Hello again all,
Well it wasn't the gaskets! There were various air leaks, now stopped, which has reduced the probelm. There were also various hoses going into wrong places thanks to those who refitted the new engine (who shall not be named), it's a wonder it ever worked at all!
Anyway unfortunately it's still not quite right. Seems to be running smoothly from cold, but when it gets upto operating temp the backfires are coming back. So back to the drawing board! The garage that currently has it called me today and said that he'd tried everything that he could think of in terms of tinkering and didn't want to just start guessing by changing parts etc, and so has effectivly given up. In fairness I appriciate his honesty rather than just throwing (my) money at it until it worked! So now I'm looking for someone else to look at it. Looking through the files it was American Vehicle Specialists in Braintree, Essex who originally fitted the S/C to it (back in 2010 prior to new engine going in earlier this year) and the current garage recommended them saying he'd sent them work from himself before. They don't have a website, but I've found their address. If they are any good then it'll work out well as they are only about 15 miles from me!
Has anyone on here used them and able to give any feedback?
Also any general ideas as to what would cause a backfire when engine is hot but not cold are more than welcome!
Cheers guys!
Well it wasn't the gaskets! There were various air leaks, now stopped, which has reduced the probelm. There were also various hoses going into wrong places thanks to those who refitted the new engine (who shall not be named), it's a wonder it ever worked at all!
Anyway unfortunately it's still not quite right. Seems to be running smoothly from cold, but when it gets upto operating temp the backfires are coming back. So back to the drawing board! The garage that currently has it called me today and said that he'd tried everything that he could think of in terms of tinkering and didn't want to just start guessing by changing parts etc, and so has effectivly given up. In fairness I appriciate his honesty rather than just throwing (my) money at it until it worked! So now I'm looking for someone else to look at it. Looking through the files it was American Vehicle Specialists in Braintree, Essex who originally fitted the S/C to it (back in 2010 prior to new engine going in earlier this year) and the current garage recommended them saying he'd sent them work from himself before. They don't have a website, but I've found their address. If they are any good then it'll work out well as they are only about 15 miles from me!
Has anyone on here used them and able to give any feedback?
Also any general ideas as to what would cause a backfire when engine is hot but not cold are more than welcome!
Cheers guys!
Woohoo! Finally fixed and working again!
Pictures to follow, but had a great weekend of light hooning in the Sunday sun! As luck would have it I had total, no rules access to a runway (+racetrack) for me and a couple of mates, so got to have a bit of a play and find the limit of grip on a damp runway (unsuprisingly, the limit was not very far away and resulted in some amusing sideways action!).
Anyway, hopefully I will see some of the other Essex yank motor owners around soon somewhere!
Pictures to follow, but had a great weekend of light hooning in the Sunday sun! As luck would have it I had total, no rules access to a runway (+racetrack) for me and a couple of mates, so got to have a bit of a play and find the limit of grip on a damp runway (unsuprisingly, the limit was not very far away and resulted in some amusing sideways action!).
Anyway, hopefully I will see some of the other Essex yank motor owners around soon somewhere!
AdeTuono said:
Go on then; what was the cause?
Detonating due to timing being out when boost came through as S/C spooled up. Ended up just taking charger off (rather than having to fit boost retarders or timing delayer for distributor) and now its back to N/A it seems much happier and is running fine (touch wood!), and TBH is still more than fast enough so I'm happy.Now deciding what to do with hole in the bonnet where intake previously stuck out. Thinking either:
a) get a piece of metal fabricated to put between carb and intake so it still stick out.
b) some sort of subtle hood scoop to go over the hole
c) some perspex to fill the hole and make a window (like the ZR1)
d) open to other suggestions (that don't involve having to buy and paint a new bonnet!)
miln0039 said:
Awesome! Sorry to resurrect this but I keep getting my eye drawn to C3s - but generally small block mid 70s cars - big block out of budget!
How do you find the performance with the NA set up? Any ideas on power etc?
Most of all though - do the mid 70s cars sound as good as they look? (True sucker for noise!!)
Cheers,
Alex
Hi,How do you find the performance with the NA set up? Any ideas on power etc?
Most of all though - do the mid 70s cars sound as good as they look? (True sucker for noise!!)
Cheers,
Alex
Power with NA setup is still very good. Esp in a car which has no traction control, ABS etc! These small blocks are very tunable - you can get uprated higher compression heads, more aggressive cams etc which will give you some pretty epic power if combined properly.
As for sound, yes, incredible! You want one with side pipes or an aftermarket stainless steel system out the back.
Mine is for sale at the moment. http://www.pistonheads.com/classifieds/used-cars/c...
Edited by Voguely on Wednesday 4th September 21:58
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