Been there and done that!

[scotstern]

I started out with a cold and hot start problem. Here is what I did.

I sent John Harvey:

My Cold Start Valve He said mine was fine

My Injectors He cleaned them and returned them

My Warm-up Regulator It was defective, he sent me a new one

My Frequency Valve He said mine was fine

My Control Pressure Regulator He said the o-rings were wrong and sent me new ones installed

He also sent me a new accumulator and fuel filter.


I put everything back together and it still did not run well so.......

I towed the car to DMC in LA. They did the following:

Cleaned the entire fuel system including the lines and the tank.

Replaced the basket holding the fuel pump and the bottom rubber mount.

Replaced the fuel lines in the tank and the lines from the pump to the hard lines in the front of the car.

Replaced the fuel filter in the tank

Replaced the fuel accumulator

Replaced the fuel filter

Checked the frequency valve, said it was bad and replaced it.

Adjusted the mixture

Replaced the micro switch on the idle circuit

After $2,000 at DMC and another $400 at John Harvey's here are my findings.

The car starts well when it is cold.

It seems to hunt for the right idle and is in the neighborhood

It runs well

I cannot hear or feel the frequency valve vibrating

It will not even begin to start hot even if I only wait 5 minutes or 1 hour or 2 hours.

I am so frustrated! Any thoughts?

Scot
6452

[Mike F]

Are you still running the original fuel pump (or an older aftermarket) with the integrated check valve? When I had my hot start issue it turned out to be the check valve in the fuel pump. Might be worth looking into.

[Ron]

I am so frustrated! Any thoughts?
Two right off:
How long does pressure stay on the air plate after you shut it off.
Have a chat with DMC LA....

[scotstern]

The fuel pump and the check valve were changed less than 1,000 miles ago at DMC LA although, that was 8 years ago. When DMC LA checked it it this week, it apparently looked good to them. As to the pressure, I suspect that it is not holding over three minutes as when I stopped in the gas station to fill it up, it would not start after I put 8 gallons in. That took maybe three minutes to fuel it and then try to start it!

Years ago, I wired a momentary push button switch in for such emergencies that activates the cold start valve and that is how I have been starting the car for years when it is hot. I was hopeful that this was behind me after my repair session this week but it appears that it is still very much with me.

I shall call DMC on Monday and they will be helpful but they are 100 miles away and their most efficient tool in the shop is the cash register which seems to work very well. I was just trying to learn what it might be so as to maybe eliminate the "change and see" method of repair and eliminate some of the labor charges that I know that this will take to solve.

Do any of these cars ever start hot? I have had mine since 1985 and it has never started hot! I have probably spent in excess of $10,000 chasing this issue over the years to no real avail. I even replaced the fuel distributor in a car that only had 12,000 miles on it!

There is one thing that I do see that I would like to ask about. I noticed that there are no shims on my pressure relief valve. There are two o-rings, a spring, but no shims. Could that be my problem?

[Delorean Industries]

The fuel pump and the check valve were changed less than 1,000 miles ago at DMC LA although, that was 8 years ago. When DMC LA checked it it this week, it apparently looked good to them. As to the pressure, I suspect that it is not holding over three minutes as when I stopped in the gas station to fill it up, it would not start after I put 8 gallons in. That took maybe three minutes to fuel it and then try to start it!

Years ago, I wired a momentary push button switch in for such emergencies that activates the cold start valve and that is how I have been starting the car for years when it is hot. I was hopeful that this was behind me after my repair session this week but it appears that it is still very much with me.

I shall call DMC on Monday and they will be helpful but they are 100 miles away and their most efficient tool in the shop is the cash register which seems to work very well. I was just trying to learn what it might be so as to maybe eliminate the "change and see" method of repair and eliminate some of the labor charges that I know that this will take to solve.

Do any of these cars ever start hot? I have had mine since 1985 and it has never started hot! I have probably spent in excess of $10,000 chasing this issue over the years to no real avail. I even replaced the fuel distributor in a car that only had 12,000 miles on it!

There is one thing that I do see that I would like to ask about. I noticed that there are no shims on my pressure relief valve. There are two o-rings, a spring, but no shims. Could that be my problem?


I would advise testing the bleed off with a CIS pressure gauge. The bleed off problem can only be a few things.

Ppr o ring
Fuel pump check valve
Injectors

These are the common starting points.

[Bitsyncmaster]

A 3 minuet hot start problem, I would not think would be a rest pressure problem. My guess would be your thermal time switch is always fireing. Have your tried pulling the CSV connector off and leaving it off?

[scotstern]

Dave, I'll try that but without the CSV how will I actually start it? It does not seem to start if that is not working.....hot or cold. I'll try it now and let you know.

Just tried it and it was difficult to start cold but it did start. You are correct that I seem to have a rest pressure problem. It only seems to hold rest pressure for about 2 minutes. Now, that is 2 minutes longer than it did before the new accumulator, new frequency valve and the fuel injectors being cleaned. Seems like something is causing this "bleed down." Could it be that I have no shims in the PCR? As I said, the o-rings are new but I do not see any shims.

Thanks,

Scot

[Ron]

Have you done anything to the FD since the plunger was (un)stuck?

[scotstern]

Have you done anything to the FD since the plunger was (un)stuck?

No, other than have DMC clean it with Berrymans 12.

[jmpdmc]

Scot,

You say that you cannot hear the frequency valve when the car is running but it sounds like an angry hornet. Are you sure your Lambda relay is functioning in the relay compartment? I would think it would have been checked before but it is worth a look.



Jeff

[David T]

With everything you have done I would still suspect the check valve at the fuel pump. The # of shims and the frequency valve have no effect on rest pressure.
David Teitelbaum

[DeLorean03]

For you to not be able to start the car after only 5 minutes means there's a big leak of rest pressure somewhere. Get the car hot - to where the cooling fans cycle - then turn the car off and press down on the sensor plate underneath the air breather box. It should have some intense resistance behind it. If not, there's a massive leak of rest pressure somewhere. A couple things it could be:

1. Fuel accumulator
2. PPR O-rings
3. Check valve on fuel pump

I agree with those who are suspect of the check valve.

[scotstern]

Thanks to all for the information / suggestions. DMC LA called today to say bring it back to them to find the issue and leave it with them for a while. That is one course of action but that involves a lot of logistics as I live in San Diego and they are in Garden Grove (LA). In the end, if I cannot find this then that is what I shall do. They also said that it could be an internal o-ring in the fuel distributor or injectors. That sounds to me like another $2,000 and I am reluctant to take that step if it turns out to be something else that is simple. I suppose that the accumulator could be bad. It came from John Harvey about two weeks ago. The o-rings appear to be fine and they are also new. The check valve is probably worth a try so that is what I'll do next.

[scotstern]

I am ready to order a new check valve. Mine has less than 1,000 miles on it but it is probably 8 years old. Anyway, I checked my fuel pump and it is the kind that has an acorn nut on the top and then a check valve on the bottom. I looked in DMC parts lists and I do not see a check valve offered. Does anyone know if they still sell them? If not, it would appear that John Harvey does but I could get it faster from DMC LA if that is still a viable part. I am reluctant to have to replace the whole fuel pump as it obviously works quite well. I would like to try to replace it myself as another $220 for removing the fuel pump to fix it, plus the part, seems fairly expensive. As I said before, I "been there and done that" last week to the tune of $2,000.

Thoughts?

Scot

[David T]

I would not consider this a really big problem. If it is the classic hard hot restart all you need to do to get it going is the plug swap till you can figure out and fix the problem. Get another check valve and make sure it is correctly installed. It isn't expensive if you can do it yourself. Just make sure not to kink the pick-up hose (put a mark on the fuel pump) and when you are done there are no fuel leaks.
David Teitelbaum

[scotstern]

I would not consider this a really big problem. If it is the classic hard hot restart all you need to do to get it going is the plug swap till you can figure out and fix the problem. Get another check valve and make sure it is correctly installed. It isn't expensive if you can do it yourself. Just make sure not to kink the pick-up hose (put a mark on the fuel pump) and when you are done there are no fuel leaks.
David Teitelbaum

Thank you! I'll call DMC LA tomorrow and see if they sell the check valve. IF so, I'll change it and report what happens. Thanks again David!

[DeLorean03]

If you absolutely have to, you can get a new pump for $99:

http://store.delorean.com/p-6558-fuel-pump-aftermarket.aspx

Like you said, would suck to do if you have to with a good pump and all, but it is an option! Hopefully, DMC-CA may be able to provide you a check valve instead of springing for the whole kit-and-kaboodle.

[scotstern]

Just to close out the loop and perhaps thereby help someone in the future, it was a bad check valve. I changed it tonight and now everything is running perfectly and it is holding rest pressure. This forum is always extremely helpful and the good advice is truly appreciated. After $2,200 it is at least now nice to know that this car will be dependable for a while fuel system wise. The real lesson learned, seems to be "drive them" as if you don't they will not stay working!

Thanks to everybody.

Scot
6452

[Mike F]

Awesome! Glad you got it sorted out!

[DeLorean03]

Just to close out the loop and perhaps thereby help someone in the future, it was a bad check valve. I changed it tonight and now everything is running perfectly and it is holding rest pressure. This forum is always extremely helpful and the good advice is truly appreciated. After $2,200 it is at least now nice to know that this car will be dependable for a while fuel system wise. The real lesson learned, seems to be "drive them" as if you don't they will not stay working!

Thanks to everybody.

Scot
6452

Heck yeah, man. That is awesome :thumbup: !!

[scotstern]

Talked to Camron at DMC-LA this morning. He was happy to hear that it was the check valve. He is an amazing person and his passion for the Delorean is more than just inherited from his father. He lives the dream and he will help guide DMC-LA, along with Danny, to new heights. I am very impressed with both of them and their way of dealing with customers. I shall now have to have my water pump changed soon and then I'll be back to totally dependable.

Scot
6452

[DMCCA Cameron]

Thanks for the kind words scot. See you in the next couple weeks.
:hihi2:


Cameron Wynne
714-554-6794
www.dmccalifornia.com