My 87 GTA with a 350 TPI has developed a problem. Recently while driving on the highway it developed a miss. By the time I got off the highway the miss had gotten worse. Was running fine, now is running very rough. When I tried to restart, it seemed flooded. Strong gas smell and gas in oil. Replaced injectors last year and coolant sensor two weeks ago. No check engine light and no codes. Any ideas where to start troubleshooting?

 

check your fuel pressure but check it over a period of time with the car turned to on but not running sounds like leaky injectors especially with gas in oil

 

first thing i would check is the fuel pressure regulator.
pull the vacuum hose off of it & check for fuel at the vacuum fitting & in the hose.
if it looks ok have someone turn the key on but don't start the motor while you watch the fitting, if you see any fuel the regulator is bad.

 

sounds like your injectors arent seated tight and theres gas "flooding" into the combuston chamber but not bad enough to cause it to hydro lock. might even be possible bad seals around the injectors. thats what i think considering how recently you changed your injectors. I'm guessing you're not a moron and used new seals right? eithere way sometimes injectors feel like they are seated tight but arent necessarily all the way. also, a way to check this is turn the ignition on and leave it for awhile (to give gas time to build up if it is a leak around your injectors) then see if it will start up.

 

Checked the fuel pressure regulator. The is no fuel in the hose. Change the oil today to get the rid of the contaminated oil. Unplugged the coolant temp sensor and the car started. It ran rough but started. Replaced the sensor again. The car would not start and flooded. Unplugged the coolant temp sensor and the car started. Again it ran rough but started. Any ideas what would cause this?

 

If you have an injector test light ('noid light) you can see if the injectors are going static when the CTS is plugged in. If so, you'll need to dig into the wire harness.

 

If you have a DVM, you can measure the voltage at the CTS's connector. It should be +5 volts across the connector with it disconnected. If its less or near zero, there is a wire fault. I cant remember the exact values, but the CTS itself should read around 1000 ohms or so with the motor cold. Odds are that unplugging the CTS masks the real problem. With the CTS unplugged, the car should still run somewhat ok, itll just throw a code. The only real things that will happen with a MAF car will be that itll run leaner then cold and probably pull some timing since the computer will see the engine temp as being 150 deg C. The only place the CTS really comes in is when cranking as the ECM uses pulsewidth tables for the startup fueling.

 

If you want resistances...