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Hi, my 91 has an extended crank, more so when it's cold. It will run, just has extended crank at start. If I cycle the key a couple times it starts better. Does anyone have any insight on this issue? Thank you, trying to keep it in the road.
 

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1997 Corolla
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Yes. Mine does the same thing, but cold here in Phoenix is like 40-50F. There is a cold start injector located in the middle of the intake manifold. You can see the metal fuel line going from the fuel rail back to it. And there is a cold start injector time switch that controls this injector. This is located near the distributor toward the front facing the front. I'm not sure of how much either of these affect cold starts if they are not working correctly. I just live with the longer crank times.
 

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1990 Toyota Corolla Wagon
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248 Posts
Hi, my 91 has an extended crank, more so when it's cold. It will run, just has extended crank at start. If I cycle the key a couple times it starts better. Does anyone have any insight on this issue? Thank you, trying to keep it in the road.



Mine has this same issue. It's the fuel pressure. It makes cold starts have long crank time as the fuel pressure builds up. While the injectors are opening to start the engine, the pressure isn't up high enough yet, so you don't get enough fuel. As you continue to crank, slowly the pressure builds up and there's enough fuel to start the engine.



There are three parts that can cause this:
Bad check valve in the fuel pump
Bad fuel pressure regulator
Leaky/stuck open fuel injector



I replaced the fuel pump with a super cheap one and it worked fine for about 2 years and then it started doing this. I think the internal check valve is failing, so it lets fuel leak back into the tank and thus loose pressure. I ran a wire on the diagnostic port from the FP+ to B+, so the pump always has power. It builds pressure and then turns off (or seems to be what happens, because I don't hear it when the car's off, but I can hear it while the engine is on. It's a loud, cheapy fuel pump).




It's possible it could be the fuel pressure regulator that's failing. Either it's leaking into into the vacuum line or it's not closing off completely when no vacuum is applied.


You can test this by removing the vacuum line to see if there is fuel or fuel smell in it. Also, with that line off, you can remove the return side to see if fuel is coming out. With no vacuum, the regulator should be closed, and not allowing fuel to be recirculated. This helps keep pressures up at higher RPM, when vacuum is lower.




Keep in mind these are just my observations on how all this works, so I may be wrong on some of this, but it sounds like a fuel pressure issue from what you've described.
 

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1997 Corolla
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I ran a wire on the diagnostic port from the FP+ to B+, so the pump always has power. It builds pressure and then turns off (or seems to be what happens, because I don't hear it when the car's off, but I can hear it while the engine is on. It's a loud, cheapy fuel pump).
This is dangerous. If you're in an accident and the fuel line ruptures your fuel pump will spray gas all over, maybe onto the hot exhaust. Imagine being injured or unconscious and you can't get out of the car while the flames build around your car. :surprise: Not to mention the danger to others.

You can test this by removing the vacuum line to see if there is fuel or fuel smell in it. Also, with that line off, you can remove the return side to see if fuel is coming out. With no vacuum, the regulator should be closed, and not allowing fuel to be recirculated. This helps keep pressures up at higher RPM, when vacuum is lower.
I believe the regulator will still let fuel through without vacuum. You can hear it flow by jumping Fp and B+ and turning the key on. The fuel pump supplies more pressure than needed, so the regulator lets pressure out. It just lets less out when no vacuum is applied.
 

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1990 Toyota Corolla Wagon
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This is dangerous. If you're in an accident and the fuel line ruptures your fuel pump will spray gas all over, maybe onto the hot exhaust. Imagine being injured or unconscious and you can't get out of the car while the flames build around your car. :surprise: Not to mention the danger to others.

Yes, it is. This is a diagnostic solution and not a permanent fix. I should have mentioned that in my reply.


I believe the regulator will still let fuel through without vacuum. You can hear it flow by jumping Fp and B+ and turning the key on. The fuel pump supplies more pressure than needed, so the regulator lets pressure out. It just lets less out when no vacuum is applied.

Hmmm, that makes it harder to diagnose a faulty fuel pressure regulator then. At least, not without a fuel pressure gauge and some way to pressurize the fuel line minus the fuel pump and fuel injectors. :think:
 

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1992 Geo Prizm
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Yes, it is. This is a diagnostic solution and not a permanent fix. I should have mentioned that in my reply.





Hmmm, that makes it harder to diagnose a faulty fuel pressure regulator then. At least, not without a fuel pressure gauge and some way to pressurize the fuel line minus the fuel pump and fuel injectors. :think:
Yup, I have the same thing going on with my 92 Geo Prizm. I've been trying to figure out why it only seems to do it when it's cold out though. I only say that because 45*F and above it never happens.Is the check valve actually swelling and working when it warmer? Or is the cold making it shrink and not doing it's job. I'm working if adding a check valve (external type from McMaster Carr) would correct the problem. Any thoughts?
 

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Hmmm... 1991 Model Year car. 27 years old. How many miles? Have good compression across all 4 cylinders? Start there, rule out compression before throwing parts at the fuel system. Compression check is cheap and easy.
 

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1997 Corolla
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I've been experimenting a little when starting cold the last few days. After it cranks for a few seconds I'll stop then turn the key to off and on and off a few times, then when I turn it to start it will start right up instantly. Next time I'll try to remember to cycle it a few times before even cranking once and see if it starts right up. The thinking here is that the fuel pump runs for a second when you turn the key to ON but then shuts off if the engine isn't running, so by cycling it a few times it will build the pressure up. I could also try jumping the Fp & B+ with key on for a few seconds before turning to START.

In my case I believe I checked the compression a few years ago and I've been passing the smog test every 2 years, so I think the compression is good.
 

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I've been experimenting a little when starting cold the last few days. After it cranks for a few seconds I'll stop then turn the key to off and on and off a few times, then when I turn it to start it will start right up instantly. Next time I'll try to remember to cycle it a few times before even cranking once and see if it starts right up. The thinking here is that the fuel pump runs for a second when you turn the key to ON but then shuts off if the engine isn't running, so by cycling it a few times it will build the pressure up. I could also try jumping the Fp & B+ with key on for a few seconds before turning to START.

In my case I believe I checked the compression a few years ago and I've been passing the smog test every 2 years, so I think the compression is good.

What I've been doing is turn the key to on, listen for the pump relay to kick off, then just bump the starter. Then listen again, and bump it again, and repeat several times until when I do bump the starter, everything is primed at the injectors, and it'll fire up. Depending on how many days I've let it sit parked, it might take a hand full of tries, or it might need only 2 tries, or it might need more than 5 tries. Some of it depends on how cold it is too. The weird thing is once you've fired it up, and say went to the beer store (3 miles away), it'll start like normal after that, until you park it for say 7 hours or so. Then it'll need 2 attempts, and then fire off. In my case, this has been going on for at least 5 or 6 years now.
If I drove the car the day before, it'll still need 3 attempts (bump the starter, let it prime, repeat 2 more times), in -10*F weather. It will eventually fire off though.

In warm weather (above 50*F) if it's sat for a week or 2, it might take a couple of prime sessions before firing off. If I use it over the summer a couple of days in a row, or the same week, it lights off with no problem. Please note, I have several other vehicles, and mainly use the Geo as a back up car now.
 
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