92 corvette no start

[corvettegraveyard]

I have been going back and forth for almost a month. I have tried a new distrubitor, no luck . I have 45 psi of fuel pressure , i have a strong / hot spark, but I have no injector pulse . My mechanic want to tell me it is the vats system but it can t be because I get crank spark and fuel pressure . Please help I have no idea why I get no injector pulse .


1. Could the car have jumped time? I had this once year's back on a gta.

2. Could the computer have gone bad ?

[CorvetteJohn]

You need to sit back and think about what the car needs. It needs fuel. What controls the fuel requirements to the ecm. The TPS. All kidding aside I have found the TPS to be the most misunderstood part of the fuel air equation.

I had my 93 start to idle high and then it stalled on me at a light and I had it towed to a mechanic I knew. It was'nt long before I got the call that said it's the ECM. Well we bought one and when we tried to start the car it still would not start. I had fuel preassure and spark but no fuel delivery from the enjectors. Out of frustration we sprayed choke cleaner into the TB whille the engine was cranking and miracle of miracles it started. We disconnected the TPS and the idle settled down some. We put a new TPS on and the car ran great.

So here is what was happening the tps did not ever code but it was telling the ecm that the engine was flooded and so the ecm was only allowing the engine to turn over with spark but no fuel. As soon as we made the engine fire with the choke cleaner the ecm thought the flooded condition was cured so it pulsed fuel.

Hope this sheds some light on the tps for you
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Throttle Position Sensor (TPS)
Copied from 1993 Service Manual
The Throttle Position sensor (TPS) is a potentiometer connected to the throttle shaft on the throttle body. It is a potentiometer with one end connected to 5 volts
from the ECM and the other to ECM ground. A third wire is connected to the ECM to measure the voltage from the TP sensor. As the throttle valve angle is changed (accelerator pedal moved), the voltage output of the TP sensor also changes. At a closed throttle position, the voltage output of the TP sensor is low (approximately .5 volt). As the throttle valve opens, the output voltage should be approximately 5 volts.

By monitoring the output voltage from the TP sensor, the ECM can determine fuel delivery based on throttle valve angle (driver demand). A broken or loose TP sensor can cause intermittent burst of fuel from the injectors and cause an unstable idle, because the ECM detects the throttle is moving.

If the TP sensor circuit is open, the ECM will set a DTC 22. If the TP sensor circuit is shorted a DTC 21 will be set. A problem in any of the TP sensor circuits will set either a DTC 21 or 22. Once a DTC is set, the ECM will use a default value for TP sensor, and some vehicle performance will return.

A personal note, when my TPS failed it DID NOT set a code other than to tell me the ECM was bad.

I used a couple of straight pins through the wires to hook the meter on

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[CorvetteJohn]

I was wondering if you have solved your problem yet? And if so what did you find was causing your problem. Knowing the cure is part of the learning process for all of us. It is how we can then offer ideas to the next poster who has a similiar problem.