Any advice on the Island Twin Turbo?

[nick@nite]

Hey, I am fairly new to DMCTalk. I bought an 82 Delorean with the Island Twin Turbo and I've slowly been bringing it back to life. It wasn't running when I bought it, a bunch of small problems. I've got it running now but there are a few problems to work out with the turbo and the engine.

Do any of you own or are familiar with the Island Twin Turbo?

[Delorean Industries]

We are very familiar with this. Contact us at [email protected] for technical help.

[nick@nite]

Another problem I am seeing at the moment is the car will not run for extended periods of time. As soon as the engine gets hot you need to wait and let it cool down before it will start again, this is at idle so the turbo shouldn't be playing a role here. Have any of you experienced this problem? Again this car hadn't been run for at least 5 years before I bought it.

[David T]

Every Island Turbo is basically a custom installed twin turbo and there can be variations in how it was installed. You didn't mention if it is a manual or an automatic. Also the mileage would be helpful. What specifically is the problem? Before digging in to the car the oil, oil filter, and air filter should be replaced. A thorough visual inspection checking all of the hoses, clamps, exhaust manifolds, hardware, vacuum lines, and electrical connections should be done. Pull the output hoses and make sure the insides are not oily, that would mean the seals on the turbo are leaking. Look for any external leaks. Did the PO tell you what shop installed/serviced it? They would be the most familiar with the car and could help if they are nearby. I owned a twin turbo that I installed from a kit I collected and assembled. Before troubleshooting the turbo system you must make sure the basic engine systems are operating properly. I also suggest replacing the plastic header bottle and making sure the cooling system is 100%. That may mean replacing all of the hoses, seals, gaskets, radiator, and belts.
David Teitelbaum

[nick@nite]

Hey Dave,
Thanks for getting back to me. It's a Manual, I wouldn't own a car that wasn't and it has 24,319 miles on it. At the moment the major problem is the engine only runs for a short period of time, 30 mins or so, and after it heats up it can't start again until it's cooled off. Since a month ago it wasn't running at all, the starter went, this is a step forward. There are also a bunch of questions about the Turbo, since it was a custom job we are looking it over quite a lot. The best info I have found so far was the instruction manual that was posted by someone on this site. Most of the Hoses and filters have been replaced, as well as the oil. The Air filter is not connected at the moment. A big overhaul of the electrical system was done, tons of worn wiring, shorts, bad relays, etc.

The Previous Owner never got it running, he pretty much gave up, this was a young kid in upstate maine so he really didn't have any resources to work with. He also didn't install this turbo system.

I was considering fully replacing the cooling system, I am curious if there is a better radiator out there. I know DMC in texas has a new model but I am not sure how this compares to the old model as far as heat dissipation goes. A big thing I have seen people doing is just installing a fan in the engine compartment to help circulate the air.

[David T]

The turbos should be OK with that mileage. If it is overheating you have to find out why. You may have blown headgaskets. Do a cooling system pressure test and a combustion gas test. Is the plastic screen in the oil fill melted? Is it using coolant? When it won't start is it cranking at least? If not then it is getting WAY too hot and maybe coolant is leaking into the combustion chambers. If the car has it's original aluminum core/plastic tank radiator, the new ones are brass and copper so they are much better. The cooling system has to be bled when refilled. There is a bleeder on the thermostat housing and you loosen the small hose on the top, right side of the radiator to let the air out. You don't need a fan in the engine compartment if the cooling system is working right.
David Teitelbaum

[Chris Burns]

My friend has a Delorean with the Island Turbo system. Pretty cool setup! Very throaty sounding.

[jmettee]

David, he didn't mention anything overheating concerns, so I'm reading his description as having the fuel system hot-start problem. To diagnose, after priming the fuel pump (or cranking the engine a few revolutions....or right after turning off the engine), the air flap on the intake should remain very firm. The fuel lines should hold pressure at approx 70-80 PSI, so the flap will take quite a bit to press down, & should hold for at least 1 hour. If within 10-20 minutes that flap is all loose & floppy, then you have a fuel system issue to fix your "hot start problem". Culprits should be suspected in this order:

1) Fuel accumulator (under middle of car, located with rear shift link/bellcrank). This is a diaphragm used to maintain fuel pressure between the fuel pump & fuel distributor

2) Fuel Pump - has a check valve to prevent draining of the fuel system when off. If the pump is old, or the tank had old fuel in it, the check valve may not be holding

3) Control Pressure Regulator (Warm Up Regulator) - located on the driver's side valve cover. Regulates primary fuel pressure going to fuel distributor.

4) Primary Pressure Regulator - the BIG hex bolt on the fuel distributor facing the back of the car. There is an o-ring in here that may tear & cause fuel pressure issues. They typically don't go bad unless messed with, but if the car did sit for a long time, especially with fuel in it, the o-ring could be suspect.


Ideally, before you rip into anything, check the air flap. If it holds, then you have a decent fuel system condition. Another thing would be to check the fuel pressure with a gauge to help direct you in the right direction.


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[nick@nite]

So the Fuel Pump and Control Pressure Regulator were replaced, after this the car came back to life and was running but shortly after the starter went and that was replaced. It is running again but not for prolonged periods of time.

I will have to check out the other culprits you had in mind... An interesting problem that was found, which was causing problems with the engine running, one of the previous owners replaced some of the hoses in the fuel system with the hosing type meant for a radiator. Needless to say it turned into jelly because of the chemical reaction with the gasoline.

Thanks for the info

[David T]

If it cranks and won't start then it sounds like the classic hot restart problem which is probably a bad accumulator, fuel pump check valve or Primary Pressure Regulator. To prove out that it isn't holding rest pressure you do the plug swap. If it starts up you have to figure out which of the 3 parts is not functioning. Most common is an old, bad accumulator.
David Teitelbaum