Permatune CDI thermal cut-out

[jpnovak]

I know there have been some posts in the past about a thermal cut out on a permatune unit. I am now convinced there is.

Several times over the past year I have driven the car in the heat of the day (or night) only to stop at the store and not be able to restart. Through the process of elimination I always found that I had no spark. This happened again the other night about 10pm when I stopped for gas on the way to the track. When I felt the CDI it was really warm.

Here is the reason I think there is a thermal cut out. I cooled the unit by placing two ice-cubes on top and letting them absorb the heat. Within minutes the car fired and ran correctly.

this same scenario happened a few other times during the two day DE. I think there is a cut out. When the car heats up while running it is fine. Once you stop it the ignition will not re-fire. Yes, I have cleaned all the contacts and have done the usual precautions. My permatune is potted so there is nothing I can check inside the unit.

I just wanted to share my experience in case someone gets stuck at the store or station. Try some ice.

[rw7810]

jamie - I experienced this a few years back. Mine would cut out while driving. went through all the nut roll with Permatune tech spt and their undying claim it is a grounding problem. I switch to an old bosch and haven't had a reoccurance.

[RoninLB]

I wonder what Early_S_Man/ Warren would say about this ?

[jpnovak]

I know that Warren has an opinion on these systems. It has been noted that other people seem to have ignition cut out or erratic performance and they all seem to correspond to elevated temps. I just wanted to add another data point.

Here are a few more.

Perma Tune? Long

[Lorenfb]

"I know there have been some posts in the past about a thermal cut out on a permatune unit. I am now convinced there is."

TOTAL B.S. ! ---------------------

Really, how naive can anyone be? A thermal cutoff is really what you need
when you're in the #1 lane on the freeway travelling at 80 or in stop-n-go
traffic on a hot summer day. You have to always be amazed at the comments
being made on the various treads.

Let's get real! Don't believe all that marketing B.S. or the B.S. you're told
by customer support when your CDI fails.

[jpnovak]

Funny Loren. From a previous post of yours in the link above...

"You really can't test the Permatune for intermittent conditions because most
problems are thermally related, i.e. the CD unit fails at a certain temp. This
is a common problem on the Permatunes because of the thermal expansion
problem with the electronic components/circuit board which results from the
potting compound being used."

Any way you want to describe it, This is a thermal cut out problem. It does not matter if the problem is due to a thermal fuse, a potting problem, threshold voltage changes on a power transistor, or delamination of the component board. Its still a thermal cutout problem caused by heat. I am mearly offering a data point that an icecube will cool enough to drive home, or your next run group at the track.

btw, I have not talked to any tech support or marketing persons at the company and they have not fed me any BS. I was just stating a fact that I have experienced. This is not being NAIVE!

[Lorenfb]

"It does not matter if the problem is due to a thermal fuse, a potting problem, threshold voltage changes on a power transistor, or delamination of the component board."

It does matter if an "idiot" designed-in a thermal fuse in a key engine
running component. In any case, this describes; a poor design and/or
a junk part!

[jpnovak]

Hey, I don't disagree about the design, designer or quality of the Permatune. I am just using what was installed when I got the car and posting a way to start the car when the CDI stops working from the heat.

[mskala]

Yep, I had the exact same problem on TWO of them. I now use a
good-old Bosch, but the good news is these type of failures are good
for emergency use, since they still work 'in general'.

[Early_S_Man]

Not knowing what is temporarily failing inside the silver Permatunes still would give me a major worry ...

I have posted before that my suggestion to ease the risk/worry for all silver Permatune owners ... would be to relocate the box inside the passenger compartment, such as to the top of the shift-coupler access cover. This would be very easy for 3-pin boxes. Six-pin or eight-pin box owners would have to deal with fabricating and 'extension cord' for the green coax, or having it done ... almost any coax except aluminum-shielded varieties [such as the cheaper grades of RG-6/U cable TV coax] could be used, but my preference would be Teflon-insulated RG-180/U or RG-188/U. Plain RG-58/U could even be used, but it isn't rated for the high underhood temps, so, a plenum-rated version intended for Ethernet networking should suffice.

[Early_S_Man]

I thought I would revive this thread and add some additional update information and comments ...

At the time of this original thread posting I had forgotten, or may not have read Lonnie Lenarduzzi's concluding statements in the following thread regarding the presence of a thermal cutout in the Permatune units.

UPDATED: What's your take on this? (Permatune)

He seemed to be ignoring the possibility that the thermal cutouts themselves may have introduced a new failure mode exclusive to the silver Permatune units!

My contention is still that the Permatune units exhibiting intermittent thermal-related failures need to be relocated to the interior of the car, such as the shift coupler cover!