shred

I have had an issue after my new engine install, it stalls after it is warm. My car is a '93 FD in pretty darn good shape. My engine light came on before so I jumped the conectors to see what the problem was and I got code 09 (engine thermosensor), again and again.

Was looking to see if anyone had a problem like this. The engine light only comes on after the car is at full temperature and the idle is low. If I continue to drive the car (get out on the freeway or other fast moving traffic) the light goes out but every once in a great while, the engine will stall for a brief few seconds then start right up again (only when the light is on). The temp never gets above normal, never any boil over. Check radiator fluid every day before I drive off and it has never used any fluid. Engine is in perfect shape, doesn't eat any oil (imagine that) and runs very strong.

No real mods to speak of, DP, Exhaust, Hi-Flow CAT, M2 Intake, G-Reddy elbow, Apexi Turbo Timer, amp (Bose is just too darn expensive to repair) - other then this, I haven't had a single problem after the engine was replaced (about 3k miles ago).

If I am moving when it happens, very quick to recover and I can keep on moving. If I am in traffic and it happens, can take a few attempts to get it going again, but it usually restarts right away.

Thanks in advance for any input to help me solve this problem and get me back on the track with confidence. I am going to replace the Water Thermosensor this weekend but I am finding it hard to believe that the car will stall at temp because of this.

Sprockett

Man, I just did this last week!
I got the same thing, only my engine died when it was cold. Anyway, the CEL came on, I checked the codes, and got code #9.
I went to Advanced Auto Parts and asked if they had it. They don't have it under the name "water thermosensor" but if you just explain to them that it is the sensor that tells the ECU the temperature of the engine so it can regulate air/fuel ratios, they should be able to find it. The part was $30 from them. It's brass, and has a black connector on the top. It is about 2 in. long.
Then comes the hard part: You have to take off the vacuum chamber, y-pipe crossover tube (from intercooler to y-pipe) and the bracket that holds that on. Look into the space in between the engine and the water pump housing and you should see a green connector. Detatch whatever hoses and lines you have to to get that connector off, then use a wrench to unscrew it. Then, take it out, replace with the new sensor, and so on...
Then, take the negative terminal off of the battery, wait about 30-40 seconds, press in the brake, reattach the terminal, and start up the engine. Check to make sure that the light does not come on. Mine has not come on since, and I have had no problem with stalling.

Just don's make the same mistake I did - make sure you have some LONG needle nose pliers. My hands got slippery from the coolant, and I dropped the sensor in that tiny space. I ended up having to use a pair of scissors to get it out

Good luck, I hope this helped
Tyler

Sprockett

Oh, and you might want to reconsider running a high flow cat, DP, and exhaust on the stock ECU - it will cause the engine to overboost, and then...well...a water thermosensor will be the least of your problems. Just my $.02

shred

thanks for the cool advice. Will have to look into a new computer. Wasn't too sure about that, car is pretty strong as-is but I have always wondered about the other things that got free-ed up when I changed all the stock parts to the aftermarket ones.

Had my eyes on a few of the new computers, will have to look a little more. This problem took precedence for now, once it is running straight again, then I was planning on doing the rest.

Thanks again, should be a painless replacement, hopefully it is the right one.