I have a hot start problem and have been searching through old threads. The only 2 things I haven't checked is leaky injectors and the ecu transistor problem. I've had my injectors taken out and professionally cleaned, and it didn't make any difference at all, and before I go about getting them rebuilt, I want to see what this ecu transistor fix is all about.

Icemark has mentionned in a couple threads about this transistor problem being caused by mechanics when they use their test light. He also mentionned that it was documented on another forum. Does anyone have a link to where he's referring to? I've searched, but couldn't find anything.

so, onto my questions:

1) many of you have mentionned this is a $2 fix. Is it an easy fix? I have experienced soldering things (I did the wiper switch relay fix myself). But I'm not an electrical engineer or anything.

2) how is this fix done? Diagrams? instructions?

3) Is there a way of testing if there is a problem in my ecu?

4) A while ago, I accidently hooked up the + and - terminals backwards on my battery because I wasn't thinking at all and put the battery in backwards. Could this have caused this, or other malfunctions in the ecu? I haven't noticed any other evident problems, and I can't remember if the hot start problem started happening right after this or not.

 

Accidentally reversing the battery can kill the ECU, but it's usually fatal, or no harm.
Since your enging has run since then, it's probably OK.
A bad injector darlington in the ECU will run that port way lean all the time, not just on hot starts.
I have a high mileage S5, and for hot starts I floor the throttle to cut fuel for about 2 seconds when cranking so it won't tend to flood.
Then I let up to about 80% throttle to get it going.

(I think of it as a security feature.)

 

yeah, I can always start it if I floor the throttle, but I don't like how it has to take so long to crank. And it is only hot starts that there is a problem, if the car sits for more than 4 hours, it will start up fine. On the reverse side, if I start it up right after it's been on or within 10 minutes of it being on last, it starts up perfect as well

 

yeah, I see your point, however, sometimes, after many hot starts in a row during a day, it will sound like it's pretty flooded. I just don't like the sound it makes and the stress it puts on my starter

 

I have another mod for hot starts.
(the secret extra security feature)
A button under the dash that grounds the fuel pump resistor relay signal at the ECU.
I just push it when cranking.
Grounding that signal at the ECU lowers the fuel pump voltage, and so the fuel pressure.
There used to be a solenoid in the vac rack for that, but it came out with vac the spider when I installed the J-spec.

 

I had the hot start problem I just put brand knew injectors in from marren motorsports in derby ct it fixed the problem right away I took it for a drive for half hour shut it of waited 2 mins it started right up and now 9 months has past it never floods my oplnion is that our injectors are worn and old cleaning them don't help because when they get hot they stay open don't forget to change the fuel filter at the same time

 

yeah, I wanted to avoid spending the money to get new injectors if possible, but I guess I will have to