bluemane500

hi ,i have an 85 manual that i recently swapped a motor. i am trying to start the car but i have no fuel pump and no spark. pin #21 will not ground (energize) the fuel pump relay, there is power at the coils power at (30)-(15) to all relays when i turn the key occasionaly it will cycle pump for a half second mostly it will not any ideas will help thanx

928 at last

First you need to recheck and clean all the electrical contact points you've disturbed. And then head for the CE panel. Pull the relay and clean the contact points thoroughly, and while you're there, I would strongly suggest cleaning every contact you can get to. Sounds like there's a faulty connection in the system, and where you last were is a good place to start looking.

In this case I'd also do a search for fuel pump problems, there's lot's of great info in the recent threads on this, particularly jumpering to test things.

928 at last

Oh Yeah,
You did clean and replace ALL the ground connections.....right?

dr bob

You can jumper the FP relay connections to see if the fuel pump will run, but... The fuel pump relay triggers on tach signals from the ignition system. Do you have spark while cranking? I'd be looking there at why the relay isn't pulling in. The few-seconds-pump-run says that the fuse and the relay itself are OK, you are missing the trigger pulses that cause the relay to close.

bluemane500

i secured all grounds , but im thinking ground is faulty, harness bolt to engine engine has ground to body ,body grounds to battery. i had a seasoned pro work on it today and determined pin #21 in LH unit will not send ground to fuel relay but he didnt know why or where its suposed to get the signal from, thats why i am here, i have wiring diagrams, seeing as i dont have spark either im wondering if some how the grounds are the culprit. tomorrow i will run a direct ground from the battery to the rear of the engine and see what happens unless someone has more to offer

bluemane500

so dr bob where does the trigger come from on pin 21 that i need??

WallyP

Make sure that the horn works, then swap the horn relay into the EZF (ignition) relay slot. Check for spark.

If no spark, might be ignition switch or crank position sensor.

fraggle

+1 crank signal must make from the cps and through the ez, then it will allow the lh to energize the fuel pump. You can test a signal with a scope, I can't recall which pins off the top of my head. The cps is on top of the bellhousing and connects to the main harness under the airbox.

bluemane500

thanx my friend ,, that is the answer i was looking for, im not looking forward to getting that sensor out, i think i may have to remove clutch and flywheel to get it out of the block, i know that the connector was brittle so i taped it all up and wire tied it together , so the connection are okay it must be the sensor i will check in the morning,i think i can get an led light at radio shack that may light up faintly

dr bob

The level at the sensor is very small. The LED isn't the right tool-- You'll need a 'scope at the EZK to see the signal change as the crank turns.

bluemane500

great news crank sensor was the culprit much love to the forum

Speedtoys

..thats 2 or 3 threads just today where this crank sensor was the solution I think.

928DK

I recently did a LH to TEC-gt conversion and my crank connector was very brittle, so i reduced the wire (was black) ~3 cm and added new connectors as a safety measure.