Hit road bump inertia switch car does not get fuel
Discussion
hit a road bump in the corse mountains and car went straight off. pushed the inertia straight in but
no fuel pump hiss to hear. checked the pump with 12v of the batt and it works. with the relay i am not sure.
have a 40A relay for it and replaced it with a 30a. also car does not start. so to get it off the moutain pass i shorted the pins of the relay for the pump so that it is running continuously. this made me get back the car to the camp site for further investigation. any ideas what could be the issue ? maybe immobilizer related or has the ineratia switch another fuse ?
its a 94 pre serp
cheers
no fuel pump hiss to hear. checked the pump with 12v of the batt and it works. with the relay i am not sure.
have a 40A relay for it and replaced it with a 30a. also car does not start. so to get it off the moutain pass i shorted the pins of the relay for the pump so that it is running continuously. this made me get back the car to the camp site for further investigation. any ideas what could be the issue ? maybe immobilizer related or has the ineratia switch another fuse ?
its a 94 pre serp
cheers
have not tired hitting it. if the inertia is not in what does the car exactly ? will the start and the ignition still work ? when i can shortcut the pump to run continiously the wiring seems to be ok from that point to the pump. i was looking maybe if there is another fuse for the inertia switch or anything else related. if my red light on the dash is not blinking the immobilizer should be fine. if i close the car by key
and dont unlock it it is blinking. also dont know if 40a and 30a of the replacement relay would make the difference that the car wont start. on the inertia switch there are three wires going in. any chance to put
a shortcu there to see if the inertia is the problem ?
and dont unlock it it is blinking. also dont know if 40a and 30a of the replacement relay would make the difference that the car wont start. on the inertia switch there are three wires going in. any chance to put
a shortcu there to see if the inertia is the problem ?
have found just one relay. checked it and relay itself is working when put below the dash
to replace one of the indicators.
what i have checked so far :
fuel pump cable from batt 12V directly --> works
shorting fuel pump on relay socket --> works
intertia switch shortend to see if problem --> inertia switch fully ok
have checked the relay socket. if pump is shortend pin 30->87 is used.
runs directly from the batt and of course with ignition off.
have checked pin 85/86 on the relay and there should be ground on 86 to make the pump work
and to let the relay work. once 86 connected to ground of the batt
pump comes up at ignition on.
my question is if anybody knows where pin 86 is fed from ? its a pink/rose
cable. i suspect a loose connection somewhere due to the road bump but dont see
where the cable goes and dont have the bible in the car.
also should the standard fuel pump stop working once a certain pressure
is reached when the engine is out ? before having this issue with ignition on
and motor off pump just primed once. now with pin 86 to ground and ignition on it
wont stop. maybe there is another circuit that controls this ?
to replace one of the indicators.
what i have checked so far :
fuel pump cable from batt 12V directly --> works
shorting fuel pump on relay socket --> works
intertia switch shortend to see if problem --> inertia switch fully ok
have checked the relay socket. if pump is shortend pin 30->87 is used.
runs directly from the batt and of course with ignition off.
have checked pin 85/86 on the relay and there should be ground on 86 to make the pump work
and to let the relay work. once 86 connected to ground of the batt
pump comes up at ignition on.
my question is if anybody knows where pin 86 is fed from ? its a pink/rose
cable. i suspect a loose connection somewhere due to the road bump but dont see
where the cable goes and dont have the bible in the car.
also should the standard fuel pump stop working once a certain pressure
is reached when the engine is out ? before having this issue with ignition on
and motor off pump just primed once. now with pin 86 to ground and ignition on it
wont stop. maybe there is another circuit that controls this ?
gacksen said:
have found just one relay. checked it and relay itself is working when put below the dash
to replace one of the indicators.
what i have checked so far :
fuel pump cable from batt 12V directly --> works
shorting fuel pump on relay socket --> works
intertia switch shortend to see if problem --> inertia switch fully ok
have checked the relay socket. if pump is shortend pin 30->87 is used.
runs directly from the batt and of course with ignition off.
have checked pin 85/86 on the relay and there should be ground on 86 to make the pump work
and to let the relay work. once 86 connected to ground of the batt
pump comes up at ignition on.
my question is if anybody knows where pin 86 is fed from ? its a pink/rose
cable. i suspect a loose connection somewhere due to the road bump but dont see
where the cable goes and dont have the bible in the car.
also should the standard fuel pump stop working once a certain pressure
is reached when the engine is out ? before having this issue with ignition on
and motor off pump just primed once. now with pin 86 to ground and ignition on it
wont stop. maybe there is another circuit that controls this ?
Junk the lot use the feed to the pump for a switch live and run a fresh thick new live to the pump .. those cables are to small anyway .to replace one of the indicators.
what i have checked so far :
fuel pump cable from batt 12V directly --> works
shorting fuel pump on relay socket --> works
intertia switch shortend to see if problem --> inertia switch fully ok
have checked the relay socket. if pump is shortend pin 30->87 is used.
runs directly from the batt and of course with ignition off.
have checked pin 85/86 on the relay and there should be ground on 86 to make the pump work
and to let the relay work. once 86 connected to ground of the batt
pump comes up at ignition on.
my question is if anybody knows where pin 86 is fed from ? its a pink/rose
cable. i suspect a loose connection somewhere due to the road bump but dont see
where the cable goes and dont have the bible in the car.
also should the standard fuel pump stop working once a certain pressure
is reached when the engine is out ? before having this issue with ignition on
and motor off pump just primed once. now with pin 86 to ground and ignition on it
wont stop. maybe there is another circuit that controls this ?
gacksen said:
have found just one relay. checked it and relay itself is working when put below the dash
to replace one of the indicators.
what i have checked so far :
fuel pump cable from batt 12V directly --> works
shorting fuel pump on relay socket --> works
intertia switch shortend to see if problem --> inertia switch fully ok
have checked the relay socket. if pump is shortend pin 30->87 is used.
runs directly from the batt and of course with ignition off.
have checked pin 85/86 on the relay and there should be ground on 86 to make the pump work
and to let the relay work. once 86 connected to ground of the batt
pump comes up at ignition on.
my question is if anybody knows where pin 86 is fed from ? its a pink/rose
cable. i suspect a loose connection somewhere due to the road bump but dont see
where the cable goes and dont have the bible in the car.
also should the standard fuel pump stop working once a certain pressure
is reached when the engine is out ? before having this issue with ignition on
and motor off pump just primed once. now with pin 86 to ground and ignition on it
wont stop. maybe there is another circuit that controls this ?
The fuel pump is controlled by the ECU - ignition on - ECU energises the fuel pump for three seconds to prime the fuel rail then switches it off.to replace one of the indicators.
what i have checked so far :
fuel pump cable from batt 12V directly --> works
shorting fuel pump on relay socket --> works
intertia switch shortend to see if problem --> inertia switch fully ok
have checked the relay socket. if pump is shortend pin 30->87 is used.
runs directly from the batt and of course with ignition off.
have checked pin 85/86 on the relay and there should be ground on 86 to make the pump work
and to let the relay work. once 86 connected to ground of the batt
pump comes up at ignition on.
my question is if anybody knows where pin 86 is fed from ? its a pink/rose
cable. i suspect a loose connection somewhere due to the road bump but dont see
where the cable goes and dont have the bible in the car.
also should the standard fuel pump stop working once a certain pressure
is reached when the engine is out ? before having this issue with ignition on
and motor off pump just primed once. now with pin 86 to ground and ignition on it
wont stop. maybe there is another circuit that controls this ?
The ECU will only bring the fuel pump back on when cranking and engine running - with the engine running the fuel pump will run continuously until you turn off the ignition off.
The ECU fuel pump circuit must get it's live via the immobiliser because you you only get the 3 second fuel pump run once you've hit the alarm fob.
By shorting the relay you must be completing this circuit (or bypassing it) so you either have a relay issue or a bad connection at the ECU.
I would try an ECU disconnect & reconnect at the ECU multiplug, if that doesn't fix it wire a switch into your current relay bypass so you can manually switch the fuel pump on and off.
You can then get on with your trip & fix the problem when you get home.
Funnily enough I had to do that very same get me home bodge on the way down to Le Mans, and to be honest my little switch is still there 2,500 miles later so I can vouch for it's reliability.
I really must find the time to fix it properly
Good luck with it, Dave.
Edited by ChimpOnGas on Sunday 3rd August 08:51
got it sorted in the morning and going fast again 
put a cable from pin 86 to batt ground to get the pump on when ignition is on. of course wont shut off after 2 seconds now but no prob anyway. once home will take a multimeter and check the cable from pin 86 to the ecu if there is a connection. if not new cable and case is closed.
lesson learned : dont go to fast in corse. some nice vids with 2 tvrs will follow
thx for all the help
put a cable from pin 86 to batt ground to get the pump on when ignition is on. of course wont shut off after 2 seconds now but no prob anyway. once home will take a multimeter and check the cable from pin 86 to the ecu if there is a connection. if not new cable and case is closed.lesson learned : dont go to fast in corse. some nice vids with 2 tvrs will follow
thx for all the help
so far after going from corse to nice to lago maggiore and a lot of passes in italy and swiss the things on the to do list once back home :
cv boots one the rear need to be changed
clutch fluid change maybe broken slave seal
rear brake pads
revise relay fuel pump connection
check the exhaust system as hit ground twice
change manifold gaskets for piece of mind
change front bushes to powerflex black same as on the rear
give the car a good clean from and touch up paint chips.
knew in advance something would happen but would do it again
cv boots one the rear need to be changed
clutch fluid change maybe broken slave seal
rear brake pads
revise relay fuel pump connection
check the exhaust system as hit ground twice
change manifold gaskets for piece of mind
change front bushes to powerflex black same as on the rear
give the car a good clean from and touch up paint chips.
knew in advance something would happen but would do it again
Looks like a fantastic trip, I always think a little breakdown (if solved along the way) adds spice when touring the continent, if I wanted a boring & 100% reliable car I'd be taking my Toyota.
This year I had a relay failure on the way to Le Mans and an HT lead failure just outside Bordeaux on a separate trip, both issues fixed on the road side, neither stopped play
But it's not just TVRs that disgrace themselves, our Le Mans Classic gang were dropping like flies.
My mate's freshly restored Porsche 912 started out with a terrible misfire then the brakes kept holding on, another Mate's Sunbeam Alpine split it's rad open entering the Le Mans campsite so I used epoxy putty & K-Seal to get him back to London.
Again, all these issues fixed out in the field & all deeply satisfying to sort, for me they only served to improve the whole boys to Le Mans adventure.
One of the reasons I enjoy the TVR so much is it takes things back to the pioneering spirit of motoring, a TVR delivers that classic car spirit of adventure in spades & in epic style.
All the things we've completely lost in modern motoring.
This year I had a relay failure on the way to Le Mans and an HT lead failure just outside Bordeaux on a separate trip, both issues fixed on the road side, neither stopped play
But it's not just TVRs that disgrace themselves, our Le Mans Classic gang were dropping like flies.
My mate's freshly restored Porsche 912 started out with a terrible misfire then the brakes kept holding on, another Mate's Sunbeam Alpine split it's rad open entering the Le Mans campsite so I used epoxy putty & K-Seal to get him back to London.
Again, all these issues fixed out in the field & all deeply satisfying to sort, for me they only served to improve the whole boys to Le Mans adventure.
One of the reasons I enjoy the TVR so much is it takes things back to the pioneering spirit of motoring, a TVR delivers that classic car spirit of adventure in spades & in epic style.
All the things we've completely lost in modern motoring.
ChimpOnGas said:
Looks like a fantastic trip, I always think a little breakdown (if solved along the way) adds spice when touring the continent, if I wanted a boring & 100% reliable car I'd be taking my Toyota.
This year I had a relay failure on the way to Le Mans and an HT lead failure just outside Bordeaux on a separate trip, both issues fixed on the road side, neither stopped play
But it's not just TVRs that disgrace themselves, our Le Mans Classic gang were dropping like flies.
My mate's freshly restored Porsche 912 started out with a terrible misfire then the brakes kept holding on, another Mate's Sunbeam Alpine split it's rad open entering the Le Mans campsite so I used epoxy putty & K-Seal to get him back to London.
Again, all these issues fixed out in the field & all deeply satisfying to sort, for me they only served to improve the whole boys to Le Mans adventure.
One of the reasons I enjoy the TVR so much is it takes things back to the pioneering spirit of motoring, a TVR delivers that classic car spirit of adventure in spades & in epic style.
All the things we've completely lost in modern motoring.
those kind of road trips are nice. lessen learned next time will take more tools with me.This year I had a relay failure on the way to Le Mans and an HT lead failure just outside Bordeaux on a separate trip, both issues fixed on the road side, neither stopped play
But it's not just TVRs that disgrace themselves, our Le Mans Classic gang were dropping like flies.
My mate's freshly restored Porsche 912 started out with a terrible misfire then the brakes kept holding on, another Mate's Sunbeam Alpine split it's rad open entering the Le Mans campsite so I used epoxy putty & K-Seal to get him back to London.
Again, all these issues fixed out in the field & all deeply satisfying to sort, for me they only served to improve the whole boys to Le Mans adventure.
One of the reasons I enjoy the TVR so much is it takes things back to the pioneering spirit of motoring, a TVR delivers that classic car spirit of adventure in spades & in epic style.
All the things we've completely lost in modern motoring.
next year doing something similar with a shorter time in corse and spending more time in sardinia.
could take the T350 or the datsun once done but most confidence i have in the chimaera. if you do those kind of trips something will suffer anyway. it will be paint chips and some more maintance work but thats no problem. was a fun trip with the tuscan broke down on the last day with a snapped throttle cable. got that fixed with a motorbike cable to make our way home. chim had been perfect with the big trunk but next time suspension needs to go up a bit. also needs to be softend down as it is more crusing instead of going wot. two tvr´s down there seemed to be quite an attraction for the crowd
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