Emergency,,,,help!!!!

Westy · 03-18-2005, 03:03 PM

I got a couple people interested in my car with a test drive tomorrow. Timing is everything.

On cold starts the motor starts right up, then RPM's fall, then sputter sputter, cough, cough, die.

Turn the key and it starts right up, then repeats scenario. Over and over until finally it starts and the RPM's hold in the high teens. After this it's perfect.

Is this the WUR? If so where can I get one quick. Anyone, anuone, anyone. I checked all relays and they're fine. What else could it be. Jeeeees I think my car is angry with me!!!

Any other trhoughts? Any help out there?

TIA Brian W

PS. If someone can talk me through what's wrong, call collect. 916-663-4002.

AAAARRGGGGGGG!!!!!!

john70t · 03-18-2005, 04:59 PM

It does sound like it needs more gas to stay running. A distant possibility could be there's air in the line from a leak, but that's been checked(?).
Other things besides the WUR sticking would be a fuel check valve that isn't holding residual system pressure(that's my guess), injectors that leak the system gas into a cylinder, or perhaps a non-functioning cold start valve(the solenoid-type upstream on the intake).

Does it make any difference if the pump is run for a minute or the pedal pushed in a bit?

Erakad · Erakad's Garage

You've probably already checked this out, but mine had very similar problems. I looked for leaks everywhere, made sure the top of the popoff valve was seating well. The answer finally found me when it backfired one morning and blew the popoff valve out! Apparently had been leaking around the popoff valve.

Westy · 03-19-2005, 05:53 AM

Is the cold start valve the only thing in CIS used for cold starting

JP911 · JP911's Garage

My targa does this on occasion and I've never tracked down the problem. If you haven't driven it much lately, it could just need some road time.

john70t · 07:08 AM

The cold start valve is the electronic injector that sprays in the intake for a few seconds to aid in starting because the engine is cold and the fuel tends to stick to the walls instead of staying vaporized.
The WUR limits fuel to the injectors when it's warm by adding more fuel pressure to the top of the main fuel plunger in the distributor(the center of the octopus) through a bimetallic spring uncurling as it heats up and pushing a plunger.

Some later model CIS(I don't think on pcars) also have a duty control solenoid(the computer uses water temp and O2 sensor) on the delivery from the pump to limit system pressure when warm.

To check CIS fuel pressure your gonna need a special kit-cheapest from JC Witney or Harbor Freight, but mabye its worth it to get a better quality one considering the expensive of the car.

john70t · 03-19-2005, 07:11 AM

Fuel pressure should be the second thing to check. CIS is notoriously fickle about having no air leaks(injector seals, boot, etc.) and this is quick.

ianc · 03:11 PM

Since the car starts right up, my guess is that the cold start valve is working properly; when the engine immediately fires, it's running off that jet of raw gas that the CSV fires into the plenum. If the CSV is not working, the engine will never even fire.

When it won't stay running, it's probably the WUR.

Quote:

The WUR limits fuel to the injectors when it's warm by adding more fuel pressure to the top of the main fuel plunger in the distributor(the center of the octopus) through a bimetallic spring uncurling as it heats up and pushing a plunger.

This is actually backwards; the WUR lessens pressure on the plunger to allow a richer mixture to the injectors for cold running.

Regardless, you're going to need to test the cold control pressure to determine if it's too high, which means you need a CIS pressure tester, as mentioned. There are published graphs of CCP versus temp for each year\model. I can probably scan one from the factory manuals for you if you need it.

If it does work out to be the WUR, it is not adjustable, although it can be made so with some modification. Either that, or buy a new one ($$$).

Good luck,

ianc

makaio · 03-19-2005, 03:38 PM

Sounds like an vacumn leak to me. But the only real way to tell is with a fuel pressure gauge. My SC had a similar problem, where when it was above 65 degrees it would start up and run fine. But when under 65 it would stumble for 5 minutes or so untill warm. It turned out to be a vacumn leak around the injector seals. I found it by gooping each seal with vasaline, and the problem went away.

Westy · 03-19-2005, 06:45 PM

OK, Now that I'm completely confused, maybe I'll take it in to a UGH mechanic

ianc · 03-19-2005, 06:55 PM

Quitter...

ianc

TC_SJ · 03-19-2005, 08:57 PM

Quote:

Originally posted by Westy
OK, Now that I'm completely confused, maybe I'll take it in to a UGH mechanic

Have mobile works check it out, cheaper than the shop

Summer is almost here!! Time to bring out your porsches

Westy · 03-20-2005, 06:53 PM

TC_SJ I will call them in the morning,,,,thanx for the tip......you might have saved me lots,,,,,thanx again. I owe you

MACHINEMON · 03-21-2005, 03:42 AM

I had that with my 75s. I found if i turned on the key and let the fuel pump run 30 sec or so it would start right up. I have a throttle on mine, located between the seat which is kinda cool, I raise the idle a little and let it warm up for a few minutes.