Im having major problems getting my 406 TPI to idle right. Ive got the "right" PROM burned...as the BLM is very close to 128 and the INT is around 131. It idled great until the other nite...and hasnt idled good since. Heres the list of what Ive checked/replaced.....

Timing set at 8*BTDC(tried 6*, 10* also)
New spark plugs, wires, cap, rotor
New coolant temp sensor
New 02 sensor(Bosch)
New TB gasket
New vacuum lines
New Fuel Filter

Checked TPS (reference voltage and signal voltage)
Checked MAP(replaced with a known good part)
Checked IAC and adjusted for minimum air
Checked ALL sensors with scan tool...showed ok

The entire exhaust is new except for the L98 manifolds.....I did just check the fuel injector's resistance and found only two to be within spec . Here's what I found on that....

Cyl 1 17.2ohms Cyl 2 14.1ohms
Cyl 3 04.8ohms Cyl 4 10.5ohms
Cyl 5 15.1ohms Cyl 6 11.7ohms
Cyl 7 16.9ohms Cyl 8 16.8ohms

I know they are supposed to be within 11-14 ohms so I think they are bad. I did check for 12v at each connector and all were getting power. While the engine is running all "seem" to be clicking like they are working somewhat. I also checked the resistance of all the connectors and all were around 1.8-1.9 ohms except for number 2...which was 2.3 ohms. Im lost here.....I know the injectors need to be replaced but what really boggles me is that the car runs FINE when its first started, like after sitting overnite. It runs good till it warms up and then idles REALLY bad. The only thing(s) I havent checked are fuel press(because I saw the injectors were bad), and the canister purge valve. I have no codes in the computer and dont know what to check. Could it just be the injectors by thereselves???? Wouldnt they make it idle rough ALL the time? Please help...........

 

You would think so but not always. My brothers 89 was doing the same thing. On startup it would run fine for about 1-2 minutes and would then start missing and running bad. After pulling my hair out, I checked the ohm readings of the injectors. Like you, I found 2 that had low ohm readings. Like 4 and 8 ohms. After replacing the one that was running 2, the car all of the sudden came to life. Replaced the 8 ohm injector and the car ran like a champ.

I bet those $99 25lb SLP injectors are starting to look good right about now.

 

I bet you checked their resistance after you'd already been running the car some? Try First thing when they are cold before you start it, bet you see a different story.

Metal expands when heated. So the coils in the injectors get tighter. So a small wear spot in the insulation doesn't touch when cold. But as soon as it gets some heat in it, it expands and shorts out a bunch of turns in the injector and there you are...

 

You are right...the car was already at operating temp....so you think thats all it is? And that would explain why it runs ok when the engine is cold...correct??? Man I hope thats all it is....Guess its time for some 25lb SLP's...

 

If the glove don't fit, you must...errr

My magic 8ball says "all signs point to yes"

 

I guess it was one of those things that cross your mind but you dont think is possible.....BUT Im starting to realize ANYthing is possible with TPI...lol Thanks for the insight......I think the 25lb SLP's will work well with my 406 anyway...


Thanks again.....