Wusapening GENERAL MOTORS GANGSTERS!

Alright, down to business....I just installed a Howell universal TBI (87-91 GM unit used on 305-454 engines) system on a 63 CHEVY runnin' a 250cid straight six.

Not sure if this information is needed to help correct the situation...

254cid (bored .30 over). Howell 560 cfm two barrel TBI system. The rotating assembly is pretty much stock. Polished, balanced and blue printed. Stock compression. "Homegrown" ported cylinder head, 1.94, 3 angle intake valve and crane roller rockers. A high tourque camshaft producing 'bout 15-16 inches of vacuum. Clifferd manifold and shorty headers. Three chamber Flowmaster (big box) with single outlet exiting in the rear. 195º thermostat.

Well, the engine fires up awesome...but then after a few minutes it will either die or if it doesn't, the second I try crusing 'round the block, the engine will not stay on while on idle. If I take my foot off the gas, no matter what the conditions are....idle or coming to a stop sign with the foot off the gas pedal...it will turn off.

It's timing is set at 16º, 40 total. HEI stock. The alternator is stock and I'm worried that may be helping to the problem. However, there is no radio, cig lighter, air con, or anything major that is using up valuable power....the only major deal is the head lights but I'm not using them either cuz I've been testing this deal during the day....So I figure I have bout 60 amps or so to work with.

One thing I'm concerned about is the water sensor that the ECM relies on. I could not tap into the water passage of Clifferd's "water heated" intake. It was impossible to do....so I put the sensor on the cylinder head (white arrow). It is just above two header pipes and I know there is fire from the combustion on the other side that is rather close to the sensor. ( I'm looking for a t-type fitting that will save me....I'm doing the searching as I type--blue arrow).

Been doing a little bit of research....TPS...IAC...PROM....and a little screw behind the throttle bracket that stops the butterflies/throttle bracket from closing any further are all suspects I'ma guessin'. Can any of these be adjusted to help the idle problem?

I believe I don't have a manifold leak....

And last but not least and by the way, thank you if you've endured this long note, can any GM dealer diagnose the problem?

Thank you for any help and it is tremendously appreciated...CHEVYTOWN FROM EAST L.A.

 

My best guess is that the sensor is reading way to high of a temp and the computer is leaning the mixture out to compensate.

 

was able to re-route the water temp sensor...