Car starts up after quite a few cranks

GotToyota?

Dedicated Member
Apr 6, 2005
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I've noticed lately that the car is taking more and more cranks to fire up when the car is cold. Once it starts up though, it's fine, and if I start the car when it's slighty warm, it starts right up. I'm using NGK spark plugs/wires, the spark plugs are the traditional NGK coppers, which have about 3-4kish miles on them. I'm pointing to the distributor/rotor since I'm pretty sure it hasn't been replaced in awhile. Should I replaces these two things and see if that fixes the problem?

-Matt
 

trydrew

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Nov 4, 2005
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Before I tore my car down (when it had BHG) It was hard to start when cold (not when warmed up). For one, my CSITS was craking around the base, and secondly, my CSI was covered with oil and shit, conpletely blocked up. I bet that is your problem.
 

crrider80

Too soon Jr.
Jun 3, 2006
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I reckon its the fuel filter. My car does the same thing when starting for the 1st time in lets say 24 hours. I switch the car from the "acc" position to the "on" position several times to get the fuel to the engine. Since the filter way back near the engine bay it takes a while for the fuel to travel to the engine. Thats just my theory. correct me if im wrong.
-Steve
 

crrider80

Too soon Jr.
Jun 3, 2006
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IJ. said:
The pump doesn't actually run untill the ECU see's the motor crank and fire a plug.

yea but doesnt the pump run for a split second when the key is turned to the "on" position?
-Steve
 

IJ.

Grumpy Old Man
Mar 30, 2005
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As far as I know no

I'm sure one of the ECU guru's will know for sure.

I guess if the CPS is near a firing point it could.

Most cars will have a few seconds as a priming pulse but I believe Mk3's don't (but I could be wrong)
 

jetjock

creepy-ass cracka
Jul 11, 2005
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Redacted per Title 18 USC Section 798
No, you're right old man ;)

Most cars will pressurize the fuel system for a bit when the key is first turned on. It's done using a tacho-relay, often called an rpm relay. Rpm relays typically energize the fuel pump for a few seconds and then go back off. This priming function is built into the relay. The relay has a little timing circuit inside that turns it on for a few seconds when it first receives power (key on). The relay then goes off and waits until it receives signals from the ignition system (usually the same signal that drives the tach) to close again. Rpm relays are common on cars, both EFI or not. The entire point of all this is to kill the fuel pump in the event of an accident if and when the engine stops.

The Soup is provided the same protection but doesn't use a tacho-relay. It uses an ECU controlled Circuit Opening Relay for fuel pump control. On the 7MGTE the COR (and thus the fuel pump) are energeized as soon as the key is turned to start. The COR has two coils in it. One is connected to the start position of the key while the other is connected to the ECU. So the COR goes on the moment the key is turned to start. Then, when the ecu sees an engine RPM (NE) signal from the CPS higher than 500, it energizes the second coil to keep the fuel pump on when the key is released.

On the N/A cars it's a bit simpler. The ECU has no control of the COR. A switch in the AFM is closed by the metering plate when airflow is sensed and keeps the COR on. (N/A onwers should keep this in mind when troubleshooting a crank but no start condition).

The end result is the same result as when using a tacho-relay: The fuel pump is slaved to the engine running. It's just done in different ways. Why Toyota didn't program the ECU to "blip" the COR (to emulate an rpm relay) when the key is first turned on is beyond me but the system seems to work well as designed.

As an aside, if the coolant temp is cold ECU also runs the fuel pump at high speed during cranking to get the pressure up quickly. All this happens in the blink of an eye (assuming the engine starts) as the key is turned to start and then released back to the run position.

Lastly, if the ECU doesn't see spark occuring (IGf feedback from the ignitor) during cranking it'll shut down injection after about 10 seconds to prevent hydrolock. This is a completely different function though and doesn't involve fuel pump control.

Got Toyota: The "TTS" is the Cold Start Injector Time Switch, genercially referred to by mechanics as a Thermo Time Switch because they're a very common method of providing cold start injector control on older cars.

Yawn...probably more than you wanted to know ;)
 

Insidious Surmiser

Formerly 89jdm7m
May 12, 2006
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IJ. said:
As far as I know no

I'm sure one of the ECU guru's will know for sure.

I guess if the CPS is near a firing point it could.

Most cars will have a few seconds as a priming pulse but I believe Mk3's don't (but I could be wrong)

hm... well, i dunno what this has to do with anything, but the old (trashed) motor i had would start up almost instintaniously, but the jdm motor i have now takes a few seconds (2-3) to start, then again, my plug wires are as old as the motor, and have sat around for a WHILE in some junk yard.
 

jetjock

creepy-ass cracka
Jul 11, 2005
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Redacted per Title 18 USC Section 798
You'd be surprised to know all the monkey motion the ECU goes through when you start the car but the bottom line is (with a good battery and everything working right) it should start pretty much at the touch of the key in most cases.
 

Mr.PFloyd

I am the Super Devil
Jun 22, 2005
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GotToyota? said:
People say if there is a clicking after you turn the car off, that it's working. Or I could be confusing that with the EFI.

-Matt
thats the efi, it clicks when you turn it onto the on position and the off.