Strange problem, no spark, LS Cerb
Discussion
Hello here, i'm a new Cerbera owner from Holland.
Have some kitcars and now my second TVR.
After owning and enyoing my Griff 500 it decided it needed a big brother.
a engine damaged Cerb Ls come up for sale, so couldnt resist........
LS2/3 engine on original MBE ecu and T5 Gearbox. Conversion done in the UK.
Long story, but rebuild the engine to good spec and it started up and worked
Bad part was that the clutch didnt. So i could not drive/test the Car. So took of gearbox, fixed clutch, that works, but now it doesnt start. Strange, didnt touch or change anything on the engine, wiring etc. Only took off the Gearbox. Been busting my head thinking what else i could have touched/changed in the proces....
Done my homework a bit here on the forum, here is a list of things i checked,
Silver key seems to work, turns everything on/off nicely...
Fuel system works, pump primes, have pressure on rail, starting with plugs out it gives fuel.
Crank sensor works ( tested it, and it gives fuel with plugs out so ecu nows engine is turning)
No Mil light on.
Checked al fuses and relays in the back, Ecu and ignition control box gets power.
Immobiliser basicly seems to work, dash, starter and fuel system operate.
So basicly it needs spark to run, but ignition system seems to be out. Coils (8 )are wired into Cerb loom, everything funtioned fine a few weeks back.
Is there a way to overide the ignition system? ( Pm when not wanting to post it public)
Any good ideas would be greatly appreciated....want to drive it badly...
Many thans, Gr Marc
Have some kitcars and now my second TVR.
After owning and enyoing my Griff 500 it decided it needed a big brother.
a engine damaged Cerb Ls come up for sale, so couldnt resist........
LS2/3 engine on original MBE ecu and T5 Gearbox. Conversion done in the UK.
Long story, but rebuild the engine to good spec and it started up and worked
Bad part was that the clutch didnt. So i could not drive/test the Car. So took of gearbox, fixed clutch, that works, but now it doesnt start. Strange, didnt touch or change anything on the engine, wiring etc. Only took off the Gearbox. Been busting my head thinking what else i could have touched/changed in the proces....Done my homework a bit here on the forum, here is a list of things i checked,
Silver key seems to work, turns everything on/off nicely...
Fuel system works, pump primes, have pressure on rail, starting with plugs out it gives fuel.
Crank sensor works ( tested it, and it gives fuel with plugs out so ecu nows engine is turning)
No Mil light on.
Checked al fuses and relays in the back, Ecu and ignition control box gets power.
Immobiliser basicly seems to work, dash, starter and fuel system operate.
So basicly it needs spark to run, but ignition system seems to be out. Coils (8 )are wired into Cerb loom, everything funtioned fine a few weeks back.
Is there a way to overide the ignition system? ( Pm when not wanting to post it public)
Any good ideas would be greatly appreciated....want to drive it badly...
Many thans, Gr Marc
I’m not great with the ignition side of things but the only thing i can think of that you may have disturbed when removing the gearbox is possibly a lambda issue. Not sure how this would manifest if both lambdas are not working correctly? Did you diss-connect them..... Would this result in no spark?.... i’m sure someone with more knowledge will be along shortly. You may need to hook it up to a laptop and get the diagnostics out.
Good luck
Good luck
Edited by Thunderroad on Wednesday 21st March 00:26
The immobiliser is a know issue for starting faults.
While you have your finger on the start button get someone to tap the immobiliser box and / or tug at the black wires going into the immobiliser box.
That may at least get the car started for you and confirm that the issue is inside there.
If the fault is there it'll be on the circuit with the heavy black wires.
Worth trying this first ....
While you have your finger on the start button get someone to tap the immobiliser box and / or tug at the black wires going into the immobiliser box.
That may at least get the car started for you and confirm that the issue is inside there.
If the fault is there it'll be on the circuit with the heavy black wires.
Worth trying this first ....
Thanx for the tips Guy's,
Immobilizer seems to work correct. Tapped it, but didnt help.
Spoke to the two TVR electronics specialist today,super nice and helpfull Guy's, realy great.
They agreed on al the checks i did, but didnt have different ideas/approaches.
Got a bit wiser about the Immobilizer stuff, so like to share what they told me,
Immobilizer cuts out 2 or 3 circuits, depends on if you have m36t of m36t2 immo box.
First model is starter, fuel and ecu, later m36t2 only starter and ecu.
But stil no running car,
Couldnt stand that is was running fine several weeks back, and normaly solve "small" problems myself.
Looked up how the Ls coils function ( 4 wires per coil) and if they Needed grounding other than with the normal plug/loom. Forums in Trump country seem to disagree on the subject, depending where you look and how monster fast your Corvette is. But interestingly found that Ls valvecovers are perfectly isolated (electric) from the rest of the engine. Gasket is silicon, bolts are in rubber mounts etc.
I suspected that my isseu was a grounding problem, as 90% of electric problems is. So got a few jumper cables and 10 feet of black wire and a handfull of amp and started to extra ground everything on the engine, ecu etc. After 5 extra grounding points got in the car and bang, it started (After cranking away many times with fuel but no spark is was banging prettig hard, hope CAT's survived)
But which one did it? Took them of one by one and found out it was an existing ground from the tvr wiringloom near the alternator ( now in front of the engine) that coused the trouble.
Didnt touch that wire, stil m6 bolted to the alternator bracket, but probably lucky it functioned weeks back, but now decided it wasnt grounding enough.
Thanx for al the help, going to drive it tomorrow the first time and run in the new engine.....
Immobilizer seems to work correct. Tapped it, but didnt help.
Spoke to the two TVR electronics specialist today,super nice and helpfull Guy's, realy great.
They agreed on al the checks i did, but didnt have different ideas/approaches.
Got a bit wiser about the Immobilizer stuff, so like to share what they told me,
Immobilizer cuts out 2 or 3 circuits, depends on if you have m36t of m36t2 immo box.
First model is starter, fuel and ecu, later m36t2 only starter and ecu.
But stil no running car,
Couldnt stand that is was running fine several weeks back, and normaly solve "small" problems myself.
Looked up how the Ls coils function ( 4 wires per coil) and if they Needed grounding other than with the normal plug/loom. Forums in Trump country seem to disagree on the subject, depending where you look and how monster fast your Corvette is. But interestingly found that Ls valvecovers are perfectly isolated (electric) from the rest of the engine. Gasket is silicon, bolts are in rubber mounts etc.
I suspected that my isseu was a grounding problem, as 90% of electric problems is. So got a few jumper cables and 10 feet of black wire and a handfull of amp and started to extra ground everything on the engine, ecu etc. After 5 extra grounding points got in the car and bang, it started
(After cranking away many times with fuel but no spark is was banging prettig hard, hope CAT's survived) But which one did it? Took them of one by one and found out it was an existing ground from the tvr wiringloom near the alternator ( now in front of the engine) that coused the trouble.
Didnt touch that wire, stil m6 bolted to the alternator bracket, but probably lucky it functioned weeks back, but now decided it wasnt grounding enough.
Thanx for al the help, going to drive it tomorrow the first time and run in the new engine.....
Mkiholland said:
LS2/3 engine on original MBE ecu and T5 Gearbox.
I admire your faith in the T5WCAll I would say is make absolutely sure the input shaft is shimmed correctly, and if possible replace the pressed steel countershaft plate with a billet one, preferably the Paul Cagnialosi version
Are there 2 steve heath conversions in holland then? I suggested to another SH coverted car owner to go the KMS ecu route because he was having trouble with that particular install.
Ive mapped another SH conversion car here in UK and it caused us all sorts of trouble, in the end traced to a box of "stuff" linking the racelogic TC through the ignition if i recall correctly. That car is currently having it's T5 taken out and converted to something more appropriate. It may well end up losing its MBE as well?
Steve Heath is a lovely chap and has done some great stuff over the years, but sadly those conversions were poor.
Ive mapped another SH conversion car here in UK and it caused us all sorts of trouble, in the end traced to a box of "stuff" linking the racelogic TC through the ignition if i recall correctly. That car is currently having it's T5 taken out and converted to something more appropriate. It may well end up losing its MBE as well?
Steve Heath is a lovely chap and has done some great stuff over the years, but sadly those conversions were poor.
Yes, now second SH converted Cerb in Holland. Original a german owner had the car converted. After 5000 Miles ( new engine) running lean burnt a piston....
T5, a lot of different opinions... weak link with a 6.0LS. But free when i bought the car
300lbft rating std, Stil running them im 2006 V8 mustangs (T5, later t45)
I like the light flywheel en Cerbera clutch rev respons and room for Exhaust.
Other SH car in Holland had a T56 conversion done (i heard) with available space resulting in low Exhaust pipes etc. Maybe owner (flying dutch)can comment, also on KMS conversion?
MBE also came with the car for free, bit older ecu, fully programable, and if it works and meets the mot on CO/Exhaust etc. who not? KMS is Dutch, but Emerald have a plug and play TVR MBE ecu conversion.
Want to drive the car as is first ( never drove it, fixed the engine, clutch, electrics first) pretty eager to see how it drives, only used to my Griffith 500 now..
i also have a bmw 530d gearbox (570nm rating std) available for when T5 blows. Same gearbox as M5, schould be good for 1000hp, 6 speed and cheap. LS converson with light flywheel, twin plate clutch etc.only £1400 (more expensive hightech conv-sets £3000+ also available from USA)
http://www.pmcmotorsport.com/153,gearbox-adapter-k...
Beter option for the money than upgrading the T5 to Quaiffe etc. i think?
Suggestions welcome of course
T5, a lot of different opinions... weak link with a 6.0LS. But free when i bought the car
300lbft rating std, Stil running them im 2006 V8 mustangs (T5, later t45)
I like the light flywheel en Cerbera clutch rev respons and room for Exhaust.
Other SH car in Holland had a T56 conversion done (i heard) with available space resulting in low Exhaust pipes etc. Maybe owner (flying dutch)can comment, also on KMS conversion?
MBE also came with the car for free, bit older ecu, fully programable, and if it works and meets the mot on CO/Exhaust etc. who not? KMS is Dutch, but Emerald have a plug and play TVR MBE ecu conversion.
Want to drive the car as is first ( never drove it, fixed the engine, clutch, electrics first) pretty eager to see how it drives, only used to my Griffith 500 now..
i also have a bmw 530d gearbox (570nm rating std) available for when T5 blows. Same gearbox as M5, schould be good for 1000hp, 6 speed and cheap. LS converson with light flywheel, twin plate clutch etc.only £1400 (more expensive hightech conv-sets £3000+ also available from USA)
http://www.pmcmotorsport.com/153,gearbox-adapter-k...
Beter option for the money than upgrading the T5 to Quaiffe etc. i think?
Suggestions welcome of course
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