I know when you bought an FC back in 1988 you didn't have to have a fuel cutoff switch to start these cars. Why is this common practice to get the car to actually turn over? I recently bought a car that has this very switch installed and if I don't "dry" crank and then flip the switch right when the car starts to turn over it won't start. I looked at another FC before this one and it was basically the same way.

 

usually it's a leaky injector problem that causes flooding. that switch is wired in the fuel pump circuit.

 

Right, I know why it's there now and what it does, but you partially answered my question with the injector thing. I'm assuming there's some sort of issue with these cars since 25 years ago this wasn't necessary. What is the best corrective action?

 

I guess I should look into either injector cleaning or replacement. Thank you.

 

Correct. It's buildup in the injectors through normal use. Witchhunter, rcengineering, cruzinperformance and many others provide the cleaning service you are looking for. People usually don't because fix it correctly because it requires work to remove the injectors, pay for the service, downtime to the car, and correct re-installation. Or the switch is a temporary fix that they never get around to finishing up.

 

mine was wired like that and would often flood on start when
1, the car was fully warmed up
2, stopped and shut off for a few minutes (under half hour)
3, tried to start.

it would flood almost every time. Turn the switch off, it would un-flood in just a few seconds of cranking and start right up; then switch on and away we go.

Eventually, I got around to replacing the injectors and didn't need the switch again. Left it there, but didn't need it

 

I'm sending off my injectors this week, honestly for such a minimal invest I feel it's worth it. The switch, IMO, is a decent idea for anti-flood purposes, but not as a crutch necessary to start the car each and every time.

 

Ya,but now that you are getting it fixed,leave it in.
You can have a "built in Security system".
Who can steal a car if they can't start it right??..(switch fuel off you can crank all day)

 

That's what I did with mine. I didn't need it every time I started the car, just after a short stop when it was excessively warm.

After the rebuild, I used the switch when parking in any kind of dicey area, or at night. The switch was mounted inside the dash behind the hood release, so if you didn't know where it was, you'd never see it. pretty good security for 'nothing'.

 

I would hate to dampen your confidence with injectors being the obvious culprit, but leave that cut-off intact for now. My lengthy (but not really troublesome) experience has been that I still have not solved difficult hot starts. My '86 S4 starts like new when cold, but cranks for 5 to 10 seconds when hot. The hotter the ambient air temp, the longer the cranking. Go figure.

Working backwards I've:
- Sent injectors to Injector Rehab for cleaning and test.
- Replaced every piece of vacuum hose.
- Replaced the appropriate water temp sensor (not simply the dash meter)
- Back in the early '90's a Mazda tech I knew punched out a check valve in or near the fuel tank, if memory serves, and that helped with another starting issue.
- Added a new fuel check valve near the engine this summer for kicks and hot starts improved, but only slightly.

Some say poor compression can be a culprit. Personally, I'm hoping next summer when it hits the 90's again my recently cleaned and improved grounds which have greatly boosted current will help out here too. Good luck with yours.

 

Thanks!!! I'll be right over.
Now we know HOW to start your Car!!!.(why would you post that??)

 

You made me laugh. thanks!

What you mean, is you know how to start my car if you have the key and it is cranking over but not starting, right?

I meant that as added security...the typical bone-head-car-thief might hot-wire or jimmy the ignition and crank-away for a while, then go away and find an easier target.

about the 'give away' here; First of all, we're all part of the RX "Family" right? So we help each other out by sharing thoughts and ideas. Second, You'd still have to break in to the car, right? Third, you need a key or you'd have to hot-wire. Fourth, you'd have to actually find out where I live. Fifth, you'd have to break into my garage. Sixth, youd have to get past my dog, who *hates* thieves. Need I go on? *sheesh* (i'm guessing you were just being amusing).

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