Delayed throttle

[David T]

Thanks for all the suggestions.

I'm going to have him drive down to my house. I will pull his FD and check and clean the plunger. I will do some other testing also if I don't think the plunger is sticky.

During warm-up the CPR aka Warm-Up Regulator is controlling the fuel to a large extent. Also the WUR is supposed to give added enrichment following a fast throttle opening, kind of like an accelerator pump. I really doubt the fuel plunger is sticking only when cold. Make sure the vacuum hoses are hooked up correctly and the small, round delay valve is oriented correctly to the WUR. As long as you are checking things make sure the vacuum hoses are OK for the vacuum solenoid on the distributor. I would concentrate on the WUR and it's associated connections since you say you replaced it and you are still having trouble.

[hmcelraft]

Delay Valve0001.pdf

Probably vacuum related to WUR and delay valve. Be sure it is not on backwards. Be sure the delay of the valve is correct.

[sdg3205]

Run a 20oz bottle of Techron through it and see what happens before u dig in too deep. That stuff does amazing things.

Is the car new to him? Or is the problem new?

[Bitsyncmaster]

Run a 20oz bottle of Techron through it and see what happens before u dig in too deep. That stuff does amazing things.

Is the car new to him? Or is the problem new?

He has had the car for 15 years. He said it has had cold running problems since 2008 but has been getting worse from then.

[Bitsyncmaster]

Delay Valve0001.pdf

Probably vacuum related to WUR and delay valve. Be sure it is not on backwards. Be sure the delay of the valve is correct.

I had him check that and it seemed good from what results he reported.

[Bitsyncmaster]

Here is another video with the air cleaner off so I could see the reaction of the air plate to the throttle. Note the backfire sometimes. It that a clue. It also looks like the delay is less with this cold run and the air cleaner removed.

https://www.youtube.com/watch?v=PnzZ...ature=youtu.be

[DMC5180]

The backfire tells me it's running lean momentarily. Perhaps this is the point in diagnosing that a fuel pressure gauge should be installed for observation. Of coarse the downside is that you have to let the engine cool overnight to get a good observation.


Dennis

[DMCVegas]

Pull those injectors one at a time, and start checking spray patterns.

[DMC5180]

Pull those injectors one at a time, and start checking spray patterns.

That's a good suggestion.


Dennis

[DMCMW Dave]

That's a good suggestion.


Dennis

No, pull them all at once and check spray patterns. They all spray at the same time, and if you do it one a time you are filling the other cylinders full of gasoline.