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Discussion Starter #1
Anyone know, does the cold start injector open just until the engine starts or does it stay open til the car warms up, im guessing the first.

I've been having a problem keeping the car running during the first minute of start up, Its eager to fire, but not too eager to stay running for the first minute or maybe less. I think its my warm up regulator set too low though at cold.

Once its warm its fine on start up. And it drives great!
 

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The cold start valve is open ONLY during cranking and only when the motor is cold. It will also time out after too much cranking time. If it starts and dies it is probably not the CSV (Cold Start Valve). More likely dirty injectors, vacuum leaks, bad CPR (Control Pressure Regulator).
David Teitelbaum
 

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What you are describing is typical of a failed warm up regulator (control pressure regulator). The cold start valve (injector) only sprays fuel into the intake manifold when the engine is on the starter and stops spraying when the starter is disengaged. The warm up regulator causes more fuel to be sprayed from the regular port injectors when it senses the engine is cold and gradually diminishes the extra fuel as the engine warms up. The warm up regulators typically fail to the "engine is warm" mode so they stop delivering any extra fuel when the engine is cold and needs it. This is why your engine stumbles when it is cold but runs good when it is warm. It is not uncommon for these regulators to fail and I had to replace two of them on my old Esprit. I know they were not cheap ten years ago and were becoming more difficult to obtain so I can only imagine what they cost these days.
 

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Lucky for Lotus owners the same fuel system is used in the Delorean with some minor differences. Contact SpecialTauto.com. He can rebuild and calibrate the CPR aka warm-up regulator. Before condemning the old one you should make sure you have all of the vacuum hoses hooked up correctly, they are not cracked or split or hard or leaking, and you have full battery voltage at the connector. Very common for the wiring to the Bi-Metallic element to burn up inside. If you have a fuel pressure gauge and the pressure chart you can confirm if the CPR is not acting correctly. Watch the control pressure as the motor warms up.
David Teitelbaum
 

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Thermal time switch controls the cold enrichment injector. Check the switch per attached pages, first. You don't have to remove the switch from the manifold; just measure the resistance before starting the engine and after it warms up. Check two flimsey terminals. Mine were hanging on two strands.
Next, check "lo-temp" switch, PITA to access. This swich grounds the ECU pin #12 acting as a "choke" during the warm up. If it is stuck open=no choke=no enrichment.
If that is OK, check the cold Control Pressure. If one of the pumps is el sicko (or fuel filter is clogged), there is "no pressure" in the whole system and WUR (even if it is good) will not increase CCP (enrich mixture) because pressure is too low and there is no place to get it from.
 

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Discussion Starter #7
My warm up regulator went bad not long after I got the car, I got several from my local junkyard til I found one with the similar heating element configuration. I think the one I used was from a Volkswagen, it has been in the car working fine for the last six months at least til recently.

I was just hoping that cold start injector didnt shut off after the cranking stops and it may be the problem. Im not a fan of messing with the fuel pressure, its a pain to hook up that pressure gauge, you cant get to the fuel dist. without removing the air cleaner box, then you have to be careful not to over push that pin into the warm up regulator or you are removing it to pull it out again. But at least its easy to access the WUR.

Has anyone done that WUR mod I have seen on Ferrari CIS's where they have a bolt on the pin to pull it back out without taking it apart? I tried tapping one of those pins with threads to make it adjustable from the outside when I went thru this before, but the pin is hard steel and broke my tap.
 

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Sounds like the ECU just forgot how to start the car. Common problem with the 1994 models. I had the problem and had to "re-teach" the computer how to start the car. What year is your car? Let me know if you want me to re-post the method of teaching your computer.
 
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