328 Cranking, but not starting - PART II no fuel

So, after replacing my crank sensors which was causing no spark:
https://www.ferrarichat.com/forum/308-328-sponsored-yellow-compass-group/154250-328-cranking-but-not-starting.html

I drove the car for a day, including 6 or 7 stops and re-starts. After sitting for two hours, I drove it to a friends house 30 minutes away. I was there 30 minutes, and was going to leave. Cranked fine but no start.

1. Tested for spark - good spark. In fact much better than before the sensor replacement. Very quick starts all day.
2. Unplugging the frequency valve makes no change. It is not buzzing when plugged in. Unplugging the blue plug on the top right of the plenum (auxiliary starting assembly) makes no change.
3. A little starting fluid in the intake, and it will catch for a moment.
4. All fuses under passenger dash are good.
5. I can hear the fuel pump relays clicking when trying to start. I swapped them with some others with no change.
6. No fuel smell after cranking without start.

Since it is in my friends garage, I won't get back to it until Sunday, but we both think fuel pump. It seemed to work fine all day, and then just would not start. Never any fuel flow problems since new. Are there any other little things that may stop fuel flow?

Thank you,

 

Thank you for all the replies. From my first post, it looks like I have done some of the suggestions.

In order of replies:
- Fuse and relays are functioning
- Unplugged the safety switch - pump does not run. Will check voltage on Sunday
- Swapped relays with known working ones. I will inspect connectors on Sunday

My plan Sunday is to focus on the fuel pump voltage and see if it is getting power, getting power and not working, or getting power, working, and fuel flow is failing somewhere else.

 

12v at relay and fuse. 0v at pump. All white connectors in upper and lower fuse/relay boxes look good.

safety switch disconnected key on 0v at pump.

 

white connector in footwell has 12v in socket, 0v on wire on connector when connected. concentrating there

 

hot wired fuel pump and it works

 

at a stop. there is an electrical break somewhere

 

fuel pump now works and car fires, BUT all of the trying has caused the ignition switch to malfunction. cranks springs back but starter stays engaged. crap

 

I have sorted everything. I am at full capabilty. I will cover everything later this week with a detailed post. Your advice (all of you) solved all three problems. Don't spend anymore time on me right now.

Thank you!

 

CONCLUSION: We determined that the car was getting spark, but no fuel. We determined that the fuel pump was not getting power. We then "hot-wired" the fuel pump and it ran, so the problem was upstream of it. Fuses and relays were all fine. We pulled the passenger floor board and inspected everything. The white connectors all looked good, but we cleaned them all while they were apart. After reconnecting the battery, we cycled the alarm off and on a few times, and it started. The alarm was installed by the original dealer in 1989. It is very well-done and thorough, but old. Out of all those things, maybe it was one or all, but that fixed it.

 

CONCLUSION 2: From post #12, the stater would not disengage after we got it running. We tried a few different things, like cranking and pulling the starter fuse, but none worked. After a lot of brain storming, we thought it was the ignition switch, so we took it apart, and attempted to put a disconnect in the starter wire on the back of the switch as a temporary solution. After a lot of thought, we concluded something was sticking. What could that be? We thought maybe a relay was sticking, so we pulled those out (the two fuel pump ones). We had them out earlier, and decided maybe they were reversed. The upper and lower fuel pump relays perform differently, and when they are in the opposite slot, the starter will stay powered and not disengage. That was it.

 

Like trying to wire a lamp while juggling...chainsaws...while being chased by a bear...on stage...while on fire... in front of the Queen. (credit to Jeremy Clarkson for the quote)