EA82 hard to start when cold

[hooziewhatsit]

My 88GL EA82/EFI has been acting up recently

 

The first time I start it in a while it'll usually fire once then die immediately, then I need to play with the throttle to get it started. Afterwards it'll idle around 500rpms for a while, but once warm is just fine.

 

A year+ ago I cut out the connector to the CTS and spliced the sensor directly into the harness. Those splices appear to still be fine.

 

Yesterday/today I unplugged the engine harness and measured the resistance of the sensor at ~4.2kOhm @ ~55*F. This matches another spare sensor I had lying around, and is pretty close to the numbers I found in the FSM. I have yet to trace the wire all the way back to the ECU .

 

I've also taken the IAC off and soaked the valve part in some chem dip and otherwise got it clean.

 

So far my suspected culprit (the CTS) appears to be fine. Is there anything else that could cause this?

 

Thanks,

-Dave

[Cougar]

I would guess the CTS sensor and circuit is ok. The EGR valve may be clogged up or pehaps the the cold start valve may have a problem.

[hooziewhatsit]

Finally got some more time to do some testing.

 

This morning I cycled the key a few times to pressurize the fuel system. Didn't make a difference. It'll crank and won't start. It will only start once I floor it (leaky injector maybe?).

 

After it warmed up it started doing the bouncing idle thing from 1100-1500rpms, even though I did clean out the IAC valve.

 

When it's running, if I manually move the EGR diaphragm it sputters and tries to die, so I think it's still sealing. I did completely remove and plug the vacuum line to the EGR solenoid.

 

Maybe I just need to suck it up and swap in the EJ22 I have

[hooziewhatsit]

And the culprit is... the Idle Air Control solenoid.

 

After testing (and adjusting) the TPS, I manually jumped 12v to the IAC, and didn't hear it click until I tapped it with a screwdriver

 

Now it'll start up just fine, but it likes to stick open and hold the idle at 2200 (again, until I tap it and it'll start working and drop the idle like it should).

 

I figure it was sticking closed when I tried to start it, so it wouldn't start unless I held the throttle barely open (leading me to check the TPS).

 

I have another one in the shed somewhere I'll replace it with. But otherwise, I think this problem is solved.

[Cougar]

Good deal. Thanks for the update.