Engine does in any acceleration

[Emit]

Anything off idle and the engine dies, I've rebuilt the entire fuel system end to end, and getting a good spray at the injectors, starts and idle is OK. Lambda ecu has power, if i jump the rpm relay i get 12v one side of the FV, if i put back in the rpm relay and start the car i get 1 to 1.5v across the FV, which sounds wrong.

Everywhere I see talks about FV buzzing... should it be buzzing if I jump the rpm relay? I can't hear anything with the engine running (exhaust leak).

Any input appreciated

[Bitsyncmaster]

Jumping the RPM relay connector brown to double yellow/red wires should make the FV buzz. That jumper powers the "main fuel relay" which in turns powers both the FV and lambda ECU. Make sure that relay is the proper type. It is different than all the other relays.

I have seen RPM relay not power the second output which drives that main fuel relay. Even an NOS RPM relay tested bad for that.

[David T]

I have seen 4 failure modes for the F/V (Frequency Valve) not buzzing;
1) The ground wire is not connected (someone forgot to put it back under the bolt on the intake manifold)
2) The mixture screw is so far out of adjustment that it won't buzz
3) The RPM relay or other wiring problem is not providing power to the Lambda ECU.
4) The plug to the F/V is dirty and is a bad connection. Plug and unplug it a few times. I have gotten more than a few going by just doing that.
If the mixture screw has not been adjusted then the motor runs way too lean because the F/V is not adding any additional fuel to make the mixture correct. That's why it is dying on you when you go "off idle". At idle the idle motor can compensate enough to make it run. Often someone figures it is running way too lean and tries to compensate for it by f-cking with the mixture screw. If the tamper plug is still in the mixture unit, no one has messed with the mixture screw. Your goal is to get the F/V to buzz.

[Emit]

Thanks to both of you for the responses, it helped me fix it, FV is buzzing away happily now!

Pin 16 of the lambda ecu is supposed to be grounded, it was not, I jumped it to confirm and the FV started buzzing (rpm relay jumped).

That ground goes through the blue bulkhead connector to below the ignition resistor bracket, and then the idle motor bracket... which has no electrical connection to the engine, so i need to fix that properly. As a load of grounds go there it must be causing other problems.

Car will now run off idle... but not happily... so onto the next challenge!

[David T]

Probably a lot of vacuum leaks and dirty fuel injectors.

[Emit]

Probably a lot of vacuum leaks and dirty fuel injectors.

True... and given that the W pipe is held on with a wood screw I have my work cut out for me!!