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View Full Version : ....another hard hot start thread


JDK
07-22-2010, 11:01 PM
Here's the details that I know for sure....
1995 PS 205 with 350 TBI , pretty sure it's MEFI 2
- very hard to start when hot ... approx 160 on gauge after a hard or long pull.
- once started, it runs beautifully
- no codes stored (checked with Codemate)
- replaced 2 wire Coolant Temp Sensor on head, with no change in starting
- starts a little easier after sitting a while with doghouse lifted
- starts instantly when hot when CTS sensor is unplugged

I'm now thinking IAC motor......... am I on right track??????....and thanks for any knowledgeable help!

Jesus_Freak
07-24-2010, 06:54 AM
Two questions:

1. Since you titled the thread "another...", can we assume that you searched the existing hot starting threads and found nothing helpful?

2. Is it hard to start from a turning over or a firing standpoint?

chico
07-24-2010, 08:56 AM
You changed the wrong sensor for the ecm,the ecm cts is below the exhaust manifold by cylinder #8,when you disconnect that sensor the ecm gives a default range to the unplugged cts.

JimN
07-24-2010, 11:54 AM
Here's the details that I know for sure....
1995 PS 205 with 350 TBI , pretty sure it's MEFI 2
- very hard to start when hot ... approx 160 on gauge after a hard or long pull.
- once started, it runs beautifully
- no codes stored (checked with Codemate)
- replaced 2 wire Coolant Temp Sensor on head, with no change in starting
- starts a little easier after sitting a while with doghouse lifted
- starts instantly when hot when CTS sensor is unplugged

I'm now thinking IAC motor......... am I on right track??????....and thanks for any knowledgeable help!

Use a multi-meter to measure the resistance of both sensors (if you still have the old one). Look in the other hot start threads for the temperature chart- if it's hot and the resistance is higher than a few thousand Ohms, the sensor is bad. I'd start there, before just assuming the IAC is bad.

How clean is the flame arrestor?

If the ECT checks out as good and it won't start, open the throttle a little and crank it. If it starts immediately, look at the IAC.

JDK
08-10-2010, 01:03 PM
Use a multi-meter to measure the resistance of both sensors (if you still have the old one). Look in the other hot start threads for the temperature chart- if it's hot and the resistance is higher than a few thousand Ohms, the sensor is bad. I'd start there, before just assuming the IAC is bad.

How clean is the flame arrestor?

If the ECT checks out as good and it won't start, open the throttle a little and crank it. If it starts immediately, look at the IAC.

Thanks for the input........... and so........
- replaced the ECT again (checked and was within the resistance specs.)
- cleaned the flame arrestor
- cleaned the IAC

and ....put about 40 hrs. on the boat since doing this.
- it starts better when hot, but every once in a while I get a real hard start.
- this hard start never happens when the doghouse is lifted
- always re-starts after 5-10 mins with the doghouse lifted (and this re-start is usually pretty easy)
- no codes showing (checked again)

A year or two ago, I replaced the 140 deg. thermostat with a 160 deg.
Do you think I am on the verge of the ECM seeing an overheat when the engine heat soaks after being shut down?... and going back to 140 deg. might help?