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My car is VERY difficult to start!

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Old 06-16-10, 01:35 AM
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My car is VERY difficult to start!

I bought my FC from this guy who had installed a switch to the fuel pump because it has trouble starting. I figured it was a leaky injector cause it floods out every time you turn the engine off. I just had my injectors cleaned and i still have trouble staring it. It usually takes me anywhere from 2 to 15 minutes of flirting with the fuel pump switch to start it. Once it starts though it runs and idles fine with no problems just starting it is very difficult. Any ideas?
Old 06-16-10, 01:41 AM
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REST IN PEACE DAVE!!!!!!

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hate to say this but its getting old n worn out. will need a rebuild soon
Old 06-16-10, 06:44 AM
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Check your compression, as said above, constant flooding like that can mean a rebuild in the near future. The switch for the fuel pump is a band aid to make it go a little longer.
Old 06-16-10, 03:29 PM
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so do you think i have a stuck apex seal or something because wouldn't it idle really rough in that case? I'm still gonna do a compression check today so we will see what that has to say.
Old 06-16-10, 03:38 PM
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Is this hot-starting trouble, or does it have trouble even when cold?

Hot start explanation & work-around: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/looking-car-has-hot-start-problems-499744/
Old 06-16-10, 05:24 PM
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Another cause of hard starts is vacuum leaks. Check compression for to determine if its worth your time to play with or not.
Old 06-17-10, 12:31 AM
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Mazdatrix has a kit to install for this problem. i have no experience with it, but they have a good reputation. It installs in the fuel lines, and provides a tiny opening between the incoming and return fuel lines. It allows the fuel pressure to bleed off after stopping, and supposedly helps a lot with the hot start problem...
Old 06-17-10, 12:53 AM
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That Mazdatrix kit is just a band-aid for someone with leaky injectors. Getting the injectors cleaned (which is not usually the main issue) would be a better route. The root problem is Mazda's start map, which is excessively rich under warm to hot conditions.
Old 06-17-10, 12:59 AM
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Well its a pain to start no matter what temperature
Old 06-17-10, 09:05 AM
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Check water thermo sensor....
Old 06-17-10, 12:18 PM
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Originally Posted by RotaryRocket88
That Mazdatrix kit is just a band-aid for someone with leaky injectors. Getting the injectors cleaned (which is not usually the main issue) would be a better route. The root problem is Mazda's start map, which is excessively rich under warm to hot conditions.
All true.

If there is an open in the WTS circuit, the ECU will either go to the default temperatre (176F) or interpret the infinite resistance as an arctic temperature. If it is recognizing the missing sensor, it should throw the appropriate trouble code, and run the mixture too lean for any cold start.

If it does not pick up the missing sensor, it will see the hi Z of the open circuit as an extreme low temp, run the injector pulse width way up, and it will flood/be too rich to start. (Ask me how I know this...)

Combine that problem with some leaky injectors (in need of cleaning) and the overly rich Mazda start map, and you have the impossible start.

Many times it is just that the connector has backed off the WTS. Pull it off, clean it with some contact cleaner, make sure its put back on fully seated, and try again.

Check for codes--during the start.

Last edited by calpatriot; 06-17-10 at 12:22 PM. Reason: typo
Old 06-18-10, 04:44 PM
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It isn't throwing any codes and has good compression but i will still inspect the WTS thanks.
Old 06-19-10, 11:32 AM
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Do you smell gas, gas on the plugs?
Could it be a fuel shortage? (fuel pump ground, sock, pump)
Old 06-20-10, 04:46 PM
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yeah i actually pulled the plugs one day when it was to flooded to start, i was doing the ATF treatment, and there were dripping wet with gas. Luckily after i let the plugs dry and did the atf treatment it fired right up! but that was the only time and its still just as hard to start now as ever. I also checked the water thermo sensor and it was on all the way but i still cleaned up the contacts and reconected it fully but the problem still remains.

and it still isn't throwing any codes

Last edited by miatahaveanrx7; 06-20-10 at 04:48 PM. Reason: forgot to say this
Old 06-20-10, 05:04 PM
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Did you take a voltage reading from the proper sensor(WTS) wire/pin with the key to on?
Old 06-20-10, 05:22 PM
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Originally Posted by miatahaveanrx7
yeah i actually pulled the plugs one day when it was to flooded to start, i was doing the ATF treatment, and there were dripping wet with gas. Luckily after i let the plugs dry and did the atf treatment it fired right up! but that was the only time and its still just as hard to start now as ever. I also checked the water thermo sensor and it was on all the way but i still cleaned up the contacts and reconected it fully but the problem still remains.

and it still isn't throwing any codes
Checking it doesn't mean visually inspecting it....
Old 06-20-10, 08:09 PM
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Get to the ECU connectors; check the voltage there on the pin for the WTS. See the FSM for the pin numbers and voltages (on/not running, on/running/at temp). Just cause the WTS is connected doesn't mean its sending the correct signal (resistance), nor does it mean the wiring is ok.
Old 06-21-10, 01:26 AM
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alright will actually check with voltages tomorrow thanks
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