89 305 tpi, fuel pump relay smokes when battery is connected, battery cable get hot. took cables loose any ideas? Jim

Unplug the the fuel pump connector at the tank and reconnect the battery cables to see if more smoke appears. You might want to add in 20-amp circuit breaker, something to kill power and an indicator to see moreso than the smoke.

If no more smoke, replace fuel pump inside tank.
If more smoke, check for shorted wiring from relay to pump.

There is a parallel power path through the oil pressure sensor under the dist, but this is a smaller gauge of wire.

the wire that causes the smoking is a small black with white tracer.when i take this one out of the connector there is no short , this wire travels across the firewall and into the passenger compartment anyone know where this wire goes. I disconnected the fuel pump and the smoking continued. Jim

Get a Haynes manual from the local parts store and check the wiring diagram.
I suspect the blk-wht wire could be to the ECM since the f/pump works for two seconds when the ign key goes to IGN normally. The ECM controls the f/pump relay next to the drvr hood hinge.

thanks Everett i'll keeep ypu posted as to the results we find

fuel pump didn't work after removing it and jumping with 12 volts, new pump in .Gas in oil,checked diaphram ,torn so we replaced regulator. No more smoking,car starts but only if we have the charger on the battery, New battery already installed. Do you think when the cables got hot it ruined the positive cable? The cable got hot enough to melt the corner of the battery. We also installed a new starter. When i check across the terminals the test light comes on any ideas? Jim

If the battery cable melted the corner of the battery case, alot of current is traveling through the cables, both negative & positive. I would replace them both with minimum 1/0 gauge cable.

You might check the continuity of the fusible links on the starter solenoid as one of them reads like it might be open, the one from the alternator since you have to have an external charger on the battery. Use the ohmmeter function of the DMM (digital multi-meter) to check with the wires and battery disconnected.

Glad to read all the smoke is gone. So it reads like tyou're making head way to get it running. A test light across the battery terminals will light. A quick check to see if the alternator is connected to the battery is to place t/light between the BAT terminal of alt and positive post of battery. If it lights, bad news, open wire. If it does not light, good connection, at least for voltage. Current wise, there may be some strands broken and this would lessen the recharge function back to the battery. Not likely to happen, but one never knows.

new cables, started when cold,1500 rpm even when warm, all of the sudden it died. fuel pressure 48psi cranks fast disconected coil wire very faint spark. don't have much history on this car. coil and disstributor look new previous owner said he replaced the distributor, cap, wires. frustrating but were still ok. glad it's not 10 degrees and needed for a daily driver like the old days.Jim

Weak spark is a sign of low primary voltage from ign switch, should be within 0.5 volt of battery/alt, faulty ign module, or bad coil. HEI's should jump a 1/2 inch gap with a blue spark. Check rotor button and the one ground wire for the coil is attached to one of the coil holddown screws.

After 90 seconds, engine should be at hot idle. It reads like engine is still at cold temp fueling if running 1500 rpm, engine is being choked out, too much fuel. Spark plugs wet after it dies? Coolant temp sensor under thermostat? Two-wire one for ECM. Reference voltage, 5 VDC, on one wire, reduced voltage on the other wire to tell ECM its warm. Sensor cold will read above 5K ohms, hot should read something around 150-200 ohms. Continuity path to ECM?

Everett, working on everthing, car now starts and runs great for about 6 minutes good range of rpm's at about 6 minutes engine wont't go over 3400 rpm's then dies and will not start back up for a couple of hours till really cooled down. i'm not real good at checking voltage or ohms but we have borrowed some known good parts to try one at a time to see if any improvement. here's a list of what we have done.fuel pump, fuel regulator, tempature switch front of engine under thermostat, sending unit left head for gauge, coil, ignition module, this engine runs great till things get hot. alot of the wires have the insulation removed a bit for probes or meters, previous owners must have been at the same place we are. fans have been wired together and don't always come on like we think they should. we now have a chilton manual and are researching it. don't know if a relay for the fans tells the computor not to let the engine start if to hot. THANKS FOR ALL YOUR HELP.. Jim

One fan is controlled by a sensor on the pass head. The other fan is turned on by ECM when A/C or DEF is selected. Both should come on for A/C. Keep plugging! You can win!

taking a break for a couple of days, to many other things need to get completed. Thanks for the help i'll keep you posted when we get back on it and get it running correctly. Jim

Sometimes getting away, clearing the head, and returning is the key. You & I may be missing something obvious.

But, 6 minutes is a good symptom. Slow O2 sensor? I think if you disconnect the O2 sensor, the ECM defaults itself to a good reading as if the O2 sensor were working. Ever try a complete ECM dump, disconnect the battery cable and let the ECM relearn?

Everett, were back at it now, pulled three codes ,14,22,44, oxy. sensor and throttle positioning sensor, put a temporary temp gauge, engine runs great till about 180. code 14 is coolant sensor we replaced that, we put sealer on the threads 2 weeks ago but still this code pops up . could the sealer not be letting the contact to the block be correct? going to replace oxy. sensor today. thanks Jim

Coolant sensor for ECM doesn't care about body being grounded. ECM supplies a reference voltage, 5 volts, to one wire, then sensor as it heats up, sends a lower voltage/current back to tell the ECM how hot the coolant is.

Make sure the wire harness to the ECM can be read with the ohmmeter. With key off, disconnect the connector and read resistance on both wires to ECM. Good continuity, good to go.

TPS - either set too low or too high or an open is on the wiper. I would think if the voltage setting is out of range, a code would be set for the out-of-range value, one for too low & one for too high. Again, use ohmmeter and watch for open holes in the action of the TPS. Center terminal to one of the other terms, very slowly go to WOT and back. Must be a smooth reading for the full stroke. Reset voltage to 0.480-0.520 volts, center terminal to the ECM return, not to ground.

Before doing anything, erase codes by disconnecting the battery for about 30 seconds, then look for code 12 before starting. Then start engine and let it relearn. May have to drive it over 35 mph.

Everett, my son checked the resistance on the injectors, 4 were out of range, real low. A guy on craigs list close by had a complete tpi set up including 8 good injectors so we went and got it. Joe tore it apart sat. night,worked pretty late. Started it sun. and it ran real good also found one wire arking off exhaust manifold. I don't understand why it ran for 6 minutes before, just one of those things. I now know more about tpi's than i ever thought i would, we really appreciate all your help Jim.

You're welcome. Injectors are solenoids, pass electrical current through a coil of wire creates a magnetic field, lifts the needle from the seat to distribute fuel, all in microseconds. And the impedance of the coil determines the driver characteristics as there are two types. One driver will drive both injectors, but a light load driver will not drive a low resistance injector.

Over time, the coil insulation breaks down, coils of wire shorts out, less mag field, less fuel. Fortunately for you, the drivers for the injectors in the ECM did not open up due to more current load. More current needed as resistance goes down to perform the same function. More heat generated, drivers work harder and eventually open up. Just as you do on a hot summer day outside, 95°+ with high humidity, you collapse.

I did the same job to an '85 Z/28 with a Corvette 350 CID. I also replaced the EGR valve and its exh temp sensor while I was there. I used Accel 24# injectors from Summit for $250 set. 305 TPI's came with 19#, 350 TPI's came with 21#. My case worked fine. I shoulda never sold the car.