Tr7 Fuel injection relay

[zekow1]

Hi Guys
I all most finished the car.In July it will be 7 years.
Haven't driven it much .
When the car gets warmed up it will just cut's off.
Have new injectors
Have new Pump.
Have new filter.
I believe its the relay malfunctioning.
Cant seem to find it .
anybody know were it is??

Started on 07 2008 still needs tweaking

[FI Spyder]

There is a combined relay whose purpose is to supply current to the fuel pump at start when the ignition switch is turned on and the current is not yet coming through the air mass meter as it is closed (keeping the fuel pump off). I don't see this being a problem when the engine is running as it isn't active then as the current is being supplied through the now functioning air mass meter which happens as soon as the engine draws in air cracking open the air mass meter flap. I haven't been able to spot where this relay is yet as it doesn't show its location in my 30+ year old OEM manual as I am missing the last pages which are showing the location of electrical components. I would suspect by fuse panel or by instrument panel would be my guess. The Bosch L jetronic manual doesn't mention it.

What could cause the engine to cut out when it warms up? A component failing when warm in ECU. I think you have a spare one, did you try swamping? A component in the electronic ignition when warm. Are you still using the stock Delco electronic ignition? The amplifier board is mounted in the coil. Bad wiring connection that changes resistance when warm? Connectors at Air Mass Meter, ECU.

Things like temp sensor, thermo-time sensor, aux air valve, cold start injector, air leak in intake system shouldn't cause it to cut out after it has been running to warm up point.

I can't see the impact switch (if that's the right term) being a problem, it's either off or on and don't think it would change based on temperature but stranger things have happened.


- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[zekow1]

I am having the same problem finding the injector relay.
The reason I think that is the problem is because my dauily driver is a 1990 Volvo 740 turbo wagon ( with only 200,000 miles on it )and about a month ago I had the exact problem . after lots of searching I found the relay was the culprit . changed it and since then it has worked like a charm.
I do not have an extra ECU it could be it???
i'll keep looking .
I want to use the car more but don't trust it will bring me back home . Its a crappy feeling.
After all the work and how good it looks and still cant enjoy it.

Started on 07 2008 still needs tweaking

[FI Spyder]

When it cuts out do you have spark at the spark plug? (ignition amplifier).

When it cools down does it start right up?

By "warmed up" have you been driving for a while. Have you tried opening the gas gap then tried it? It's a "sealed" system but there may be a blockage, a vacuum may build up enough to over come the pump although in that case the pump should overheat due to not enough gas flowing through it and it typically gets louder.

It could be ECU although the TR7 Bosch units are very reliable unlike the Lucas TR8 ones which have been known to fail.





- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[busheytrader]

Sorry, I don't know where the relay is kept.

I had exactly the same problem when I fitted the V8 engine into mine. It had the Opus electronic distributor fitted to the Rover SD1 at the same time as our cars.

As soon as my newly converted TR7V8 reached operating temperature the sparks and rev- counter would drop to zero. This was common to these electronic items back in the day but once cooled down it would work until it warmed up again.

Hopefully the affected relay is one of the common types used in many parts of the wedge.

Adam



TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 14" 5 Spokes or Maestro Turbo 15" Alloys, Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991 courtesy of S&S V8 conversion kit (built not bought) and big brake kit.