Hello people,
I've got a horrible misfire or over fueling problem when i try to pull away when engine is cold. Reaches 1500 revs and goes limp.
It's a 2wd 88 saph.
I've changed dizzy/phase/rotor/leads/grpA coil/ignition mod.
I'm running out of ideas
Can anyone help?
Also when it goes limp throws out loads of fuel!

 

Measure signal voltage from coolant and intake air temperature sensors when cold.

 

Check the coolant temp sensor on the back of the head.

Steve

 

Thanks for replying.
How do i check the signal voltage from coolant and air temp sensors
Steve what does the coolant sensor do?

 

As said first one to check is the CTS output, trouble is it's hard to do accurately unless you know the scales, i.e. Temp Vs volts.

Thing is it's a good idea to change them every so often and are cheap as well, I brought one but haven't fitted it yet as they are awkward to get to!

But if this was the suspect you would get problems when at running temp as well?

Martin

 

Thanks Steve,
is it easy to find and how would this effect the misfire?
I'm trying to understand...
Gav

 

The CTS is one of the main (And important) inputs to the ECU, it is merely a thermistor, it's the same sensor as the ACT but in a different housing.

These can go out of range after a while giving false readings, so the ECU is being told the engine is colder than what it actually is, hence more fuel is injected.

Martin

 

Thanks martin.
At running temp the problem is still there but no where near as bad, still i can notice its getting worse... I will replace this item if i can find it!
Thanks again

 

2WD= Look at underneath of plenum/inlet at the rear of the engine, its on the left hand side of the cylinder head at the back. It's a 2 pin blue coloured sensor, I got a replacement from MSD.

Martin