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-   -   Cranks but no start (https://www.rx7club.com/new-member-rx-7-technical-256/cranks-but-no-start-1127051/)

JonnyTsunami714 06-07-18 05:12 PM

Cranks but no start
 
Hi I’m new to this. I own a 1988 Fc turbo. My issue I’m running into right now is what the title says but I’ve replaced the fuel pump(walbro 255), fuel filter(Oem Atkins Rotary), spark plugs(have spark & NGK), the injectors have been cleaned. I just removed the fuel injectors to get checked out to see if they’re still working correctly. I’ve checked the fuel lines and they seem fine also checked the lines using a bottle to see if fuel comes out. I’ve already did the flooding trick. Any help is appreciated. If I don’t respond immediately my instagram is JonnyTsunami_714

Akagis_white_comet 06-08-18 02:28 PM

Before anything else is replaced or altered, let's recap what has been changed:
Fuel Pump- Walbro 255: Wouldn't affect ability to start unless pump is dying. Can be bench tested just like a light bulb, will make a 'poot poot' sound. Fake Walbros sound like electric screwdriver motors

Fuel Filter- OE Mazda: Unless clogged, no issue with starting. Still a good idea to have a known fresh one though. Is the in-tank filter (aka the fuel sock) on the pump clear too?

Spark plugs- NGK ones: Are you sure they are the correct heat range? BUR7EQ for leading, BUR9EQ for trailing. Some people run BUR9EQs in all 4, but this is generally for modified cars with bigger turbos or more boost. If done on a stock-ish car, the 'colder' BUR9EQs in the leading spots will make it more difficult to start. When removed after trying to start the car, are the plugs wet or dry?

Fuel injectors: Known cleaned/working ones make things much easier to diagnose. After 20+ years, my 20b's injectors were downright NASTY. Sent them to Injector Rehab, got a clean bill of health after being cleaned.

Battery/Ground: Are these in known good condition? Checking for power at injectors, coils, etc and comparing against battery voltage. If there is significant voltage drop, I'd be examining your harness further.

Based on the diagnostic work you've done, and I commend you for doing so, this sounds like something relevant to the stock N332/N333 ECU such as a sketchy MAF. It's been awhile since I touched a stock ECU

lduley 06-12-18 07:04 AM

out've all the money throwing you've done, you haven't done a basic compression test, gotta go back to the beginning and start with that

JonnyTsunami714 06-24-18 05:24 PM

So I was able to do the atf trick and it got it running I let it burn off as much atf that was visible and noticed that the idle was a bit lower than what it use to be at but it kept its idle so I assumed everything was okay but when I shut the car off and let it sit for a little bit it had the same issue of not starting up again, so as of now the spark plugs, plug wires both NGK and both are the correct ones. It has a walbro 255lph, new fuel filter, cleaned out all the grounds, battery is fully charged and is still in good condition. The next thing I’m assuming to do is a compression test but is there a possibility it just floods itself to easily because I have the stock Ecu and I believe the injectors are a bit higher than stock and it use to flood a lot but all I would do it unflood it and it’d be okay and never ran into the issue I’m having now.

JonnyTsunami714 06-24-18 05:25 PM

And also when I turn my key to crank over the car it doesn’t sometimes crank it like if the starter is out or doesn’t want to crank it


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