Engine problems after back from shop

[rockola1454]

Hi all,

I recently had a few coolant leaks (minor), and had some work done at a local shop. They replaced a bad radiator, and a few things in the engine compartment with parts from Delorean.com. After getting the car back, all leaks are gone but it has two new problems, not sure if they are related:
1) The car is extremely difficult to start when cold
2) Once started, the car runs ok for about 5 minutes, then quickly loses half its horsepower. I.e., unless the pedal activates the passing gear, the car has zero acceleration.

I took back to the shop and they replaced the cold start valve, but the problems remain. I have come to the conclusion they don't know how to fix it, especially since it used to run great before they did the work.

Has anybody heard of this odd behavior? The loss of horsepower as the engine warms up has me very perplexed. :shocked: It only has 42k total miles, and the engine was rebuilt by McFly motorsports in Ohio before I had bought it, ran great.

[nofear365]

They replaced a bad radiator, and a few things in the engine compartment with parts from Delorean.com.

What things in particular?

[David T]

While they were "mucking about" they probably knocked off a vacuum hose or an electrical connection on the motor. You are probably correct, they are not very experienced on Deloreans. You "could" have them call the vender you bought the parts from and they can talk them through how to fix this.
David Teitelbaum

[DMCMW Dave]

Hi all,

1) The car is extremely difficult to start when cold
2) Once started, the car runs ok for about 5 minutes, then quickly loses half its horsepower. I.e., unless the pedal activates the passing gear, the car has zero acceleration.

1 - Has anybody heard of this odd behavior? The loss of horsepower as the engine warms up has me very perplexed. .

The wire is probably off the thermotime switch, or it was connected backwards and burned it out. Or the ballast bypass wire is off the resistor or disconnected at the starter. Replacing the cold start valve was 100% the wrong thing to do, I don't think I've ever seen one fail.

2 - Are you sure that it's really losing power, and not just trying to start out on third gear all the time? That will feel like a very weak engine (and its rough on the trans). If that's the case the shift computer is either malfunctioning or disconnected in some way.

[jmettee]

If that's the case the shift computer is either malfunctioning or disconnected in some way.

If they messed with the throttle spool, I would say it could be very likely they may have not gotten the kick-down cable adjusted correctly....if it is a trans problem.

[sdg3205]

Tell us more about your location, VIN etc etc.

There may be another member close by that is way more DeLorean savvy then your previous mechanic.

[Jimmyvonviggle]

Tell us more about your location, VIN etc etc.

There may be another member close by that is way more DeLorean savvy then your previous mechanic.

I agree, fill in your personal information. This should definitely be a prerequisite to posting.

[sdg3205]

Are you in Rochester NY?

[rockola1454]

Thanks for all the replies! sorry i hadn't had time yet to fill out my profile yet, i'm in rockville, md. My vin last 4 digits are 06290.

I definitely can feel it shifting when it has less power, so its probably not that it starts out in 3rd gear. But on a straightaway even the passing gear has little effect after the car has been running a while. I forgot to mention its an automatic.

Ill grab the receipt and post what all was replaced during the work. If anybody relatively close by wants to take a look at it, that would be awesome! I can come to them :)

[Ron]

They replaced a bad radiator, and a few things in the engine compartment with parts from Delorean.com.

What things in particular?+1

[Bitsyncmaster]

Thanks for all the replies! sorry i hadn't had time yet to fill out my profile yet, i'm in rockville, md. My vin last 4 digits are 06290.

I definitely can feel it shifting when it has less power, so its probably not that it starts out in 3rd gear. But on a straightaway even the passing gear has little effect after the car has been running a while. I forgot to mention its an automatic.

Ill grab the receipt and post what all was replaced during the work. If anybody relatively close by wants to take a look at it, that would be awesome! I can come to them :)

Great to hear of another Maryland owner. If your down my way anytime, your welcome to stop by my house. I can check your engine out but not very familiar with the auto tranny.

[rockola1454]

Thanks, Dave! Actually I think you had helped me with the doors a while ago! :cool:

Well, some good news! Inspecting the wires around the starter and cold start valve, I just happened to see that one of the contacts in the blue cold start valve plug had worked its way out of the plug. I was able to repair the plug, and the car seems to start right up now.

Expectedly this has no effect on the loss of acceleration/power over time. I'm not sure the best places to look, but I didn't notice anything disconnected looking around the engine. I'll take a look around the transmission tonight.

Here is the list of parts we ordered for the work:
-- water pump --
1 x 102149 - WATER PUMP HOSE
4 x SP10097 - HOSE CLAMP
2 x 102146 - SEAL-’O’ RING
1 x 102405 - SWITCH, THERM VAC
1 x 102478 - SWITCH, LAMBDA SENSOR
2 x #9 - SP10350 - HOSE CLAMP
2 x #10 - 102481 - HEATER PIPE HOSE
-- radiator --
2 x #9 100506 - HOSE-RAD CONNECTOR
4 x #8 SP10352 - HOSE CLIP
1 x #7 100502 - RESVR. CONN HOSE
2 x #6 SP10348 - HOSE CLIP

I'm very suspicious of the "THERM VAC SWITCH." I see what the part looks like on delorean.com, where could I find this on the car? And is there a way to tell what hose should go where?

-Chris

[jawn101]

I'm very suspicious of the "THERM VAC SWITCH." I see what the part looks like on delorean.com, where could I find this on the car? And is there a way to tell what hose should go where?


That switch goes into the Y-pipe under the intake manifold. You can tell what hose goes where by looking at the vacuum routing diagram :)

- Switch is #26 on this parts diagram
https://store.delorean.com/images/Category/large/1-3-0.gif

- Vacuum routing diagram (look at 'thermal control valve', highlighted in the lower right corner)
http://images1.wikia.nocookie.net/__cb20100125040717/deloreantech/images/f/f6/VacuumRoutingDiagram.png

[Bitsyncmaster]

Thanks, Dave! Actually I think you had helped me with the doors a while ago! :cool:

-Chris

Now I remember....you needed a torsion bar adjustment. I did not reconize your user name.,

[vwdmc16]

WUR and coldstart wires swapped? ive done that and my car was hard to start and had little power.

[rockola1454]

Well, I found the vacuum switch, it's buried so deep I couldn't see it directly but was able to trace at least the distributor advance solenoid vacuum hose to it, which went to the last nozzle (which seems correct according to the routing diagram). After driving a few minutes and experiencing loss of power, I pulled the electrical plug off the "distributor advance" vacuum solenoid, and could hear the idle change, so I presume this is correct - that the solenoid is supposed to activate after the engine warms up?

If my diagnostics above are correct, I guess I have to find some other things to check :)

I don't think the coldstart wire was swapped, since it starts great now after I repaired the blue cold start valve plug....