Discussion
Well thought it's about time for a quick update on the "still not sorted" 390SE.
Tonight I picked it up after its diff rebuild which had been removed, stripped, inspected, new seals all round, brake calipers were all okay but cleaned up and new pads fitted. I now have one leak free diff.
The not so good news, as reported previously, the near side A frame has been badly patched due to corrosion and the suspension bush adjacent to the weld melted into a blob so I'm going to pull that off and send it to RT Racing for a repair and refurb.
Compression check was also carried out. Last year it was checked by the previous owner and all pots had 180psi to 200psi pressure. This time, despite having done only a couple of dozen miles, compressions were all between 110psi and 140psi. So not sure if one of the two sets of gauges were inaccurate or what? Test was with all plugs out, hot and cold and throttle wide open. I've got my own gauge buried somewhere in a box so I'll dig it out and check myself to see which sets of figures I can match. If still low I'll squirt some oil down the bores to see if it is bore wear or more likely valve leakage.
Engine still starts and runs on 7 cylinders for the first few minutes - tonight I've checked the elecricals to each injector and also strapped on a set of HT spark plug indicators and all is well. It does appear that number 4 is the culprit so I'm suspecting an injector not working correctly? I've got two spare sets so I'll swap one over in the next few weeks.
Only other thing I've noticed is play in the steering column - both where it bolts under the dash but also about 20mm of movement at the bottom where it goes through the bulkhead. Given the fact that it had a new MOT on it last year I'm a little surprised there's so much play.
Car is also running very rich and once warm will not re-start due to over fuelling. At some point when I've sorted the misfire and compressions I'll spend a lump of cash to have Mark Adams set it up. I'm assuming no point doing that until all gremlins are resolved.
I think I'll assume the car will be a non-runner for much of this year and just enjoy the 350i while I slowly plug through the various gremlins. Kids taxi service and weekends away will mean there's not a load of useful time to really spend on it certainly for the next three months.
Still, it looks nice in the garage......
Tonight I picked it up after its diff rebuild which had been removed, stripped, inspected, new seals all round, brake calipers were all okay but cleaned up and new pads fitted. I now have one leak free diff.
The not so good news, as reported previously, the near side A frame has been badly patched due to corrosion and the suspension bush adjacent to the weld melted into a blob so I'm going to pull that off and send it to RT Racing for a repair and refurb.
Compression check was also carried out. Last year it was checked by the previous owner and all pots had 180psi to 200psi pressure. This time, despite having done only a couple of dozen miles, compressions were all between 110psi and 140psi. So not sure if one of the two sets of gauges were inaccurate or what? Test was with all plugs out, hot and cold and throttle wide open. I've got my own gauge buried somewhere in a box so I'll dig it out and check myself to see which sets of figures I can match. If still low I'll squirt some oil down the bores to see if it is bore wear or more likely valve leakage.
Engine still starts and runs on 7 cylinders for the first few minutes - tonight I've checked the elecricals to each injector and also strapped on a set of HT spark plug indicators and all is well. It does appear that number 4 is the culprit so I'm suspecting an injector not working correctly? I've got two spare sets so I'll swap one over in the next few weeks.
Only other thing I've noticed is play in the steering column - both where it bolts under the dash but also about 20mm of movement at the bottom where it goes through the bulkhead. Given the fact that it had a new MOT on it last year I'm a little surprised there's so much play.
Car is also running very rich and once warm will not re-start due to over fuelling. At some point when I've sorted the misfire and compressions I'll spend a lump of cash to have Mark Adams set it up. I'm assuming no point doing that until all gremlins are resolved.
I think I'll assume the car will be a non-runner for much of this year and just enjoy the 350i while I slowly plug through the various gremlins. Kids taxi service and weekends away will mean there's not a load of useful time to really spend on it certainly for the next three months.
Still, it looks nice in the garage......
Hi Keith..Out of interest i think the AFM was touched previously in an attempt to sort out the mis-fire so maybe that could need a reset?..Not sure how you do it though...
Might be all it needs to sort out the fuelling...Was the ECU ever refurbished?...I think there may of been so many things that were done to try to remedy the issues that they could quite easily of made them worst or created new issues...I personally would be going back over everything that Scott did as its possible that something may have happened unbeknown to anyone that might be a simple solution.
If the ECU was not professionally rebuilt then i would get it done...Its £200 and comes with a lifetime guarantee ...(BBA Reman).
Remember all the faffing around you had just changing a distributor...Its possible that something is incompatible due to its under engineered design compared with the Lucas over engineered design.
Does look a beaut mate.....Ziga
Might be all it needs to sort out the fuelling...Was the ECU ever refurbished?...I think there may of been so many things that were done to try to remedy the issues that they could quite easily of made them worst or created new issues...I personally would be going back over everything that Scott did as its possible that something may have happened unbeknown to anyone that might be a simple solution.
If the ECU was not professionally rebuilt then i would get it done...Its £200 and comes with a lifetime guarantee ...(BBA Reman).
Remember all the faffing around you had just changing a distributor...Its possible that something is incompatible due to its under engineered design compared with the Lucas over engineered design.
Does look a beaut mate.....Ziga
If that's still running the original injection system DO NOT let the ECU leave the car. The original 3.5L 4CU was recalibrated to suit the 390 engine and if you give it to anyone the chances of getting it back working better (or even properly) are slim. You should also not randomly swap the airflow meter as the AFM and ECU were calibrated as a matched pair.
There is no 'reset', no remap, no CPU exchange. It's an analogue computer and works by summing and differencing the input signals to arrive at a fuelling solution that at best is approximately correct over some part of the rev range.
A 'remanufactured' exchange unit is likely to be a straight 3.5L version which will never run right as long as Muslims love Allah.
Apart from Mark Adams there is nobody who knows how to properly tune these ECUs... if there was we'd have heard by now and be flocking to them.
As to the original issue... if all 8 pots have near-identical compression values then irrespective of those values it is likely to be OK. When the RV8 has been stood for a while the cam followers bleed down so don't lift the valves properly which bu99ers up the airflow straight off. If one or two cylinders were way off I'd say head gasket or broken rings (been there, wiped the sweat off with the T-shirt)... but all 8?
It could be a poor connection to the injector plug; they get rived around that much by people it's a wonder any of them work.
We've been through all this before and I'll say it again: the quickest way to diagnose faults with the RV8 injection is with a splitter or breakout box. I can work out most injection electrical faults in under 5 minutes with mine and a multimeter (and a scope if I'm feeling techie
). For one questionable injector you can switch it on or off and fire it at will; if it's working you can hear the difference.
Don't forget also that the ignition system has to be in 100% condition, no tracking, insulation breakdown or even wet plugs. If the coil doesn't make a fat spark then the ECU doesn't see a clean trigger signal and will not fire the injectors. This can manifest as a misfire.
There is no 'reset', no remap, no CPU exchange. It's an analogue computer and works by summing and differencing the input signals to arrive at a fuelling solution that at best is approximately correct over some part of the rev range.
A 'remanufactured' exchange unit is likely to be a straight 3.5L version which will never run right as long as Muslims love Allah.
Apart from Mark Adams there is nobody who knows how to properly tune these ECUs... if there was we'd have heard by now and be flocking to them.
As to the original issue... if all 8 pots have near-identical compression values then irrespective of those values it is likely to be OK. When the RV8 has been stood for a while the cam followers bleed down so don't lift the valves properly which bu99ers up the airflow straight off. If one or two cylinders were way off I'd say head gasket or broken rings (been there, wiped the sweat off with the T-shirt)... but all 8?
It could be a poor connection to the injector plug; they get rived around that much by people it's a wonder any of them work.
We've been through all this before and I'll say it again: the quickest way to diagnose faults with the RV8 injection is with a splitter or breakout box. I can work out most injection electrical faults in under 5 minutes with mine and a multimeter (and a scope if I'm feeling techie
). For one questionable injector you can switch it on or off and fire it at will; if it's working you can hear the difference.Don't forget also that the ignition system has to be in 100% condition, no tracking, insulation breakdown or even wet plugs. If the coil doesn't make a fat spark then the ECU doesn't see a clean trigger signal and will not fire the injectors. This can manifest as a misfire.
Hi Ian...By "Reset" i meant to say calibration...Couldn't think of the word for a minute...Im wondering if the AFM was adjusted to help make it run at some point which has effectively put it out of calibration?...The company i suggested don't just refurb the units to one standard ...I do remember someone soldering dry joints in a post concerning this car but I'm unsure if it was done..I guess if the iron is too hot then maybe there is a possibility of making matters worst...I remember speaking to Mark Adams a couple of years ago and he strongly advised against DIY ECU repairs...Even down to being very careful as regards to static electricity which apparently can cause irreparable damage to such a basic system... As you say...TEST...TEST...TEST...And a bit more testing to be sure...
mrzigazaga said:
I do remember someone soldering dry joints in a post concerning this car but I'm unsure if it was done..I guess if the iron is too hot then maybe there is a possibility of making matters worst...I remember speaking to Mark Adams a couple of years ago and he strongly advised against DIY ECU repairs...Even down to being very careful as regards to static electricity which apparently can cause irreparable damage to such a basic system.
Part of the problem with resoldering is that you can make a good joint bad or a bad joint worse, as well as a bad one good It's possible to reflow the solder around a component lead but for it to still not 'bond' properly with the lead, especially if there's a bit of oxidation or the lead has been arcing whilst making intermittent contact.
Most soldering irons work around 300 degrees which is fine for most components; surface-mount devices can be a bit more susceptible to overheating but temperature-controlled irons help with that.
If you feel that it's taking a long time to get the solder to flow, let it cool then ty again adding a bit more solder to start with.
Static can be a hazard but in my... er...
... 36 years 
of electronics I've only had one case I know of where it did occur; I was working on a house burglar alarm system when I took my jumper off and immediately went to feel if a transistor was getting hot. I saw the bloody static spark jump from my fingertip to the PCB, the alarm instantly went haywire and wouldn't reset as it had fried the microprocessor.I've never seen a Lucas ECU go pop despite extensive PCB-fondling without earth protection... which is not to say it couldn't happen of course.
We have full static protection at work for PCB-level repairs but the guys still regularly handle bare PCBs without any apparent ill-effect.
The play in the steering can be sorted by replacing the bulkhead bush, or can be greatly improved by fitting a ball bearing instead. This has been covered previously. You should be able to search and find the info. My 400se has a steel bearing as standard and is much better than my old 350which had a nylon bush.
Gents, thanks for the responses. Just for clarity on the ECU/AFM situation, when I got the car it did have a newly refurbished ECU that Scott had sorted through ACT. The AFM on the car had been played with and the mixture was all over the place. I have managed to buy a "matched" AFM and Tornado upgraded ECU from a 390SE which made the car run much sweeter once the cold start misfire clears. It revs clean, pulls very strong and sounds superb. The cold misfire is there using either ECU/AFM combinations and with both the car certainly appears to be over fuelling when cold. I've disconnected the cold start injector which certainly has helped. I have checked the injector connections and cleaned them all up, but no difference. The engine has had the V8 Developments "Stealth" camshaft fitted which is quite lumpy. Could this be affecting initial start up?
Maybe when Mark Adams breathes his magic on the car the misfire and cold start will be resolved. Mark has recommended I bought the larger Jag AFM (which I have) so he's asked that I send him this AFM and the Tornado upgraded ECU so he can check them both and remap the ECU to suit the larger AFM. He says that should be "good enough" to then get it across to the rolling road at Cheltenham and then he will set it up properly across the rev range.
I'll investigate the steering and loose dash board this Monday to try and see the issue, plus do yet another compression check out of curiosity.
Cheers.
Maybe when Mark Adams breathes his magic on the car the misfire and cold start will be resolved. Mark has recommended I bought the larger Jag AFM (which I have) so he's asked that I send him this AFM and the Tornado upgraded ECU so he can check them both and remap the ECU to suit the larger AFM. He says that should be "good enough" to then get it across to the rolling road at Cheltenham and then he will set it up properly across the rev range.
I'll investigate the steering and loose dash board this Monday to try and see the issue, plus do yet another compression check out of curiosity.
Cheers.
Hi Keith...I do believe that most performance cams will cause some lumpy running...My FPR on start up shows 45psi even though it is set to 36-38psi but settles once warmed up ...I think the 390SE was around 38-42psi?...Most Wedges are rich on start up..I know Scott changed the CTS but is it the correct one?...There is a listing for an EFI Classic RV8.
Sounds like it needs to be set up properly by someone who knows what they are doing....Getting closer mate...
Sounds like it needs to be set up properly by someone who knows what they are doing....Getting closer mate...
TVRleigh_BBWR said:
if the car does not have an adjustable FPR then it maybe worth getting one, as should make things easier to set-up.
Best get as many small things sorted, so Mark can sort the important things. He's a nice bloke and no one knows more about RV8 EFI.
Hi, yes it does have an adjustable FPR. It's a Lucas unit with adjuster on the top. When running it's sat at 36psi. The engine is a John Eales unit and was originally running a BL WL9 Motorsports camshaft. Best get as many small things sorted, so Mark can sort the important things. He's a nice bloke and no one knows more about RV8 EFI.
colin mee said:
Keep at it.will you keep the pair when its finish. Looks very impressive two wedges in a line
Not sure what to do in the future. 350i is still running original rubber bushes and standard engine. It's as comfy as an old pair of slippers and starts, goes, stops brilliantly with new HiSpec brake kit. It's happy to potter along at 1000 rpm all day. It's not a show car but reasonably tidy and is rare given the 4 clock "SEAC" style dash.390SE is fully polybushed with new shocks so suspension is harsh. Engine is very "cammy" and isn't happy pottering at low revs but bloody hell when you put your foot down it goes like stink. The interior and exterior is stunning, the chassis like new and the SEAC spoiler is... liked by some!
Chalk and cheese really at the moment. I'm hoping that when the 390SE is properly set up I'll fall in love with it. At the moment the trusty 350i is my best friend.
Quick update. Pulled all the plugs tonight and did a cold compression check with my 30 year old push in (rubber bung type) compression tester and all were within 5 psi of 170psi so I'm feeling a little happier on that front. I think the gauge at my local garage is way out. Last year Scott took two sets of readings, cold and hot and all were similar. 190psi cold and 210psi warm.
All plugs were clean and if anything slightly lean. So it runs too rich when cold and fractional weak at normal operating temperature. Definitely a little job for Mr Adams I think. I'd better not spank it hard until the mixture is properly set.
Cold start misfire is definitely No 2, although only for 30 seconds this evening. Spark is good so must be injector issue. I'll get one refurbished and drop it in.
There's a new problem with the driving lights. Previously they would work either with dipped or main beam. This evening if I've got dipped beam and turn them on then the main beam on the headlights comes on as well. It's as if there's a short between driving and main beam. Main and dipped beam on their own are fine. All was well the other week so something has changed. I'll get the SH bible out and have a check with the wiring diagrams.
All plugs were clean and if anything slightly lean. So it runs too rich when cold and fractional weak at normal operating temperature. Definitely a little job for Mr Adams I think. I'd better not spank it hard until the mixture is properly set.
Cold start misfire is definitely No 2, although only for 30 seconds this evening. Spark is good so must be injector issue. I'll get one refurbished and drop it in.
There's a new problem with the driving lights. Previously they would work either with dipped or main beam. This evening if I've got dipped beam and turn them on then the main beam on the headlights comes on as well. It's as if there's a short between driving and main beam. Main and dipped beam on their own are fine. All was well the other week so something has changed. I'll get the SH bible out and have a check with the wiring diagrams.
B@man said:
Maybe you already checked but is the cold start injector still connected ?
unplugging it is an easy fix for cold start overfueling !
Hi yes I've already unplugged it which improved things a fair bit. With it in, on start up, if the engine is not up to temperature and I try a re-start it just floods. Cheers.unplugging it is an easy fix for cold start overfueling !
Forums | Wedges | Top of Page | What's New | My Stuff