Car Starts and then stalls unless I idle it at 1500 rpms for a few mins.

[havlc2u]

I have had multiple issues with idle but the car starts but then stalls unless
I idle it at like 1500 rpms for a few mins. then at that time the idle drops like it is normal still have a slight surge at idle but nothing big. Then noticed that when I tried to drive it that at over 2000 rpms it seems to be fine but anything below that
and it sputters and has no power at all.

I am going to test the IAC. The car was fine before the my engine swap. Just wondering does it matter that I am running a 6 bolt block with a 2g head and still have the 99 ecu. I have no link or wideband at this time.

When I smell the exhaust it does smell like fuel. The plugs actually look just fine
blt has been done but going to perform another one.

 

[technodsm]

When my IAC went out on me the windings shorted out my ECU... Took a ECU replacement and a new IAC. Always checK out the IAC BEFORE ecu REPLACEMENT or you would hace to replace ecu GAIN... MY BAD.... Hopefully you never smelled burn't electronics if your IAC has gone bad. If the IAC fails open circuit no problem just repace the IAC. If thy short out they can destroy a replacement ECU...I would totally check the IAC and upgrade to a modern replacement that is apparently improved over the initial OEM version.

 

[92boostinawd]

Try testing out your ISC. Had a similar problem turned out to be bad isc.

 

[5150DSM]

Sounds like a CTS (coolant temp sensor) to me. Check across the pins with an ohm meter, if the car is cold the reading should be low, 50-150 ohms. If you get something like 10K ohms or just a dead short then you know the sensor is done.

 

[DSM1G90]

Usually the temp sensor.

They go bad and the ECU thinks that the water temp is 77* being the default temp setting.

 

[brianksm]

does it start up and idle fine when its warm?

 

[havlc2u]

Actually at start up the rpms warm or cold go to about 1100. Then it will drop to like 200 or 300. A lot of times stalls the first start sometimes it will idle between 200 to 600 then idle up to like 800. I replaced the temp sensor yesturday. Which I replaced the one highest up on the housing hope that's the ecu one. Same results.

 

[BigTyla]

You're looking in the right place. It's either the IAC, ECU, temp sensor, or some combination of the three. Check the temp sensor first as it's the easiest to test. Then check your IAC. There are many threads here describing how to test the IAC with an ohmmeter. If both of those turn out okay, you'll need to inspect your ECU. Often times a bad IAC will pop the board.

 

[havlc2u]

You're looking in the right place. It's either the IAC, ECU, temp sensor, or some combination of the three. Check the temp sensor first as it's the easiest to test. Then check your IAC. There are many threads here describing how to test the IAC with an ohmmeter. If both of those turn out okay, you'll need to inspect your ECU. Often times a bad IAC will pop the board.

Thanks I will see what I can find out about these.