Re: [DML] cold engine acceleration problems

["DMC Joe" <dmcjoe@xxxx>]

Walt,

Your problem is more that likely related to a problem in the acceleration enrichment circuit. This is a very common problem in the CIS fuel injection system.

Here are answers to your questions.
Question 1: Are these symptoms indicative of a bad regulator?

A: It's possible but much less likely than an acceleration enrichment problem.

Question 2: Did my local mechanic rip me off for replacing this regulator
before?

A: Could be: but more than likely they may have mis-diagnosed the problem.

Question 3: If the problem is the regulator, is it possible to take it apart
and fix it? i.e., could it be clogging up with fuel system crud?

A: Unlikely.

Question 4: Since the cold start circuit is only active while the starter is
engaged and failure of the thermo-time switch could cause flooding, is my
problem a flooded engine?

A: No; the cold start valve effects cold starting, not cold running. 

Question 5: Could flooding of my engine cause it to not accelerate well
until the engine is warmed up? Or is the warm-up problem caused by
something other than a stuck thermo-time switch?

A: Answer at the opening of this post.

Question 6: If 12 volts from the starter circuit is applied to the heater in
the thermo-time switch, how long will it take for it to open the circuit?
What I want to know is if these switches are meant to open-circuit before
the starter disengages. Or does it take continued starting attempts to heat
this switch enough to open the circuit to prevent flooding?

A: The time varies between 0 and 18 seconds depending on the engine water temperature.

Question 7: Where is the best place to buy a new thermo-time switch? Do I
get it locally, or should I buy it online? How much should I pay, and what
part cross-reference should I ask for?

A: The time-temperature switch is part # 102125 priced at 24.65. You can order this item from our On-Line-Store or your favorite DeLorean parts dealer. This is a Bosch item which normally sells for around 30.00 from other sources.

Question 8: See question 7 only now I'm looking for a different switch.

A: The cooling fan switch is part # 100816G and is priced at 43.63. I don't agree with your statement "this bad-engineering fiasco". This part operates exactly the same as in many other cars. We have found no unusual problems with this section of the cooling fan electrical system. When replacing this switch be sure to also replace the seal to prevent further leaking.


"We're here to help you"

DMC Help / De Lorean Services / <dmchelp@xxxx>
Web Site: <www.deloreanservices.com>

----- Original Message ----- 
From: Walter 
To: dmcnews@xxxxxxxxxxx 
Sent: Tuesday, August 29, 2000 11:07 AM
Subject: [DML] cold engine acceleration problems


I need some help figuring out my engine problems:

The symptom is that while my engine is cold or warm (but not yet fully
warm), it idles okay, but any attempt at acceleration is counter-productive.
The engine coughs and sputters instead of increasing the RPMs. This doesn't
happen every time I start the car from cold, but it happens often enough to
be very annoying. I am wondering if this could be due to a bad warm-up
regulator (a/k/a control pressure regulator). I paid a local mechanic $750
to replace this part a few months ago. It was $500 for the regulator and
$250 for the labor.

Question 1: Are these symptoms indicative of a bad regulator?

Question 2: Did my local mechanic rip me off for replacing this regulator
before?

Question 3: If the problem is the regulator, is it possible to take it apart
and fix it? i.e., could it be clogging up with fuel system crud?

Also, I got busy reading the service manual and figured that maybe my
problem was in the cold start circuit. So I checked the thermo-time switch
(a/k/a temperature switch). I found that it is permanently stuck in the
cold position no matter how warm the engine gets.

Question 4: Since the cold start circuit is only active while the starter is
engaged and failure of the thermo-time switch could cause flooding, is my
problem a flooded engine?

Question 5: Could flooding of my engine cause it to not accelerate well
until the engine is warmed up? Or is the warm-up problem caused by
something other than a stuck thermo-time switch?

Question 6: If 12 volts from the starter circuit is applied to the heater in
the thermo-time switch, how long will it take for it to open the circuit?
What I want to know is if these switches are meant to open-circuit before
the starter disengages. Or does it take continued starting attempts to heat
this switch enough to open the circuit to prevent flooding?

Question 7: Where is the best place to buy a new thermo-time switch? Do I
get it locally, or should I buy it online? How much should I pay, and what
part cross-reference should I ask for?

Also, while I was diagnosing the above problems, I noticed that my radiator
fan thermostat (a/k/a cooling fan switch) is dripping coolant. And it also
sounds like it is out of range.

Question 8: See question 7 only now I'm looking for a different switch.

Question 9: Instead of replacing this switch with the same thing that can
leak, would it be better to plug this bad-engineering fiasco and replace it
with a surface mounted thermostat instead? And if so, how, who and what is
involved?

Good luck answering these!

Walt Tampa, FL






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