Mysterious, challenging no start

[desmoines12]

Hi all. I have only posted to this forum a few times and have little to offer, but really appreciate any help. I drive a 93 corolla wagon with the 1.8 and a manual transmission. The problem started as a crank but no start, and I got some help diagnosing it as a dead fuel pump. I replaced it, and the car ran fine, to and from work the next day, a round trip of around 50 miles. I parked the car in the evening, came out a few hours later, and the same thing happened. I was concerned that I'd put the new pump in incorrectly and fried it, and had the car towed to a well reviewed japanese auto place. During a long week, they claimed to have traced to problem to the ECU. I found them a used one, they installed it, and the car fired right up. He said something about blowing out the fuel lines, which had a little blockage, but everything was good on my 25 mile trip to work. I came out 9 hours later, and the car only started on the 4th or 5th try, lots of cranking and then eventually it caught. While trying to start the car there was sometimes a buzzing from behind the console. I drove the car home, parked it, and got intermittent start from the car, and it died more than once while driving around the block. Same occasional buzzing behind the console, and some crazy tachometer jumping when the engine turned on. This time the car went to a different mechanic. They eventually decided that the distributor and sparkplugs were bad, and after replacing them decided that the newer ECU was also bad. They then swapped in the original ECU. They told me they'd driven the car a lot, and were positive they'd fixed the problem, but when I showed up to collect the car it would not start. I have thrown a lot of money at this issue, and am thinking about cutting my losses and getting out. What else could they possibly be looking for? All fuses and relays are good. Some loose wiring somewhere? Wiring harness? Should I give up?

[topnotch]

am not as technical as some of the guys here but have you check if all the grounds are good? what about the starter motor? or thers a possible wire shortage along the wire loom the problem seems electrical and not mechanical.

[Bitter]

weak alternator now?

[good_old_geo]

this sounds like either a faulty main relay located behind the console or a vacuum leak. Id try checking for a vacuum leak first. I remember when I had my no start problems recently the car would have a hard time starting after my timing belt change because I didnt tighten the valve cover bolts properly. watch this vid

You Tube

You Tube

[speedy25]

So which relay was buzzing behind the dash?

They arent supposed to. There is probably a cold solder joint in the bad one causing all your troubles.

-SP

[sequoiasoon]

I read one thread that mentioned the fuel pump relay is directly behind the radio area on the firewall. Seems VERY coincidental to me based on your sound description and fuel pump issues.