Gtpguy

It was a brand new gauge kit by the looks of it. Took it out and the button just fell out. No spring, o-ring or anything holding it in. All I could do was put it back on, try holding it tight, clamping the hose, nothing worked. Embarrassing. What's the benefit to the type with the hose besides an impromptu fuel shower?

Gtpguy

Hooked up the battery charger at work and it read 13.6 at start up and go to 13.9 volts running. Shut it off and it read 14.0. It definitely started faster with it hooked up to it. It got me thinking that this slower start has been getting worse since I replaced my ignition switch in the column. Would that be worth looking into?

Injuneer

If the starter is cranking slowly, the problem would most likely be in the wiring between the battery and the starter - corroded cables, corroded terminals, damaged wire strands, etc.. When the key is turned to start, the power draw from the ignition switch is not that great. It simply operates the relay in the starter solenoid, to close the 12 volt circuit from the battery (and the pull-in coil). It's the heavy wire direct from the battery to the starter motor that carries very high (200+) amps. That wire has to be heavy gage, undamaged, with clean connections at the battery and the starter. The starter is grounded to the block. The solenoid may pull 20+ amps to engage, but will drop to 10 amps or less as the starter cranks the engine.

If you are concerned about the ignition switch, check for voltage at the wiring connector for the pin that supplies the “start” function - yellow wire, pin “A” on connector 2:

http://shbox.com/1/starter_charging_93.jpg

The amp numbers above are “typical” and not specific to the LT1 engine.

Gtpguy

I live 5 miles from work. Close to 15 lights with rush hour. So most of its driving is stop and go sub-2000 rpms 99% of the time. Hardly any WOT or spirited driving. For the last 9 months or so the slow starting has come about. I did the ignition switch about that time ago. However, I don't think it's related now.
For the last week I've been driving my Trans Am how a TA should be driven. Numerous WOT bursts. The hard starts are gone. Starts right up right away.

Theories linked?: 1] With the grandma driving, the alternator isn't spinning enough to charge the 4yr old battery enough for the next restart. 2] The 4yr old napa alternator isnt good enough either. 3] The stock 93 tune running the LT4 is going lean during normal driving and the original injectors are flooding the cylinders and possibly leaking after turn off producing a hard start with puddled fuel in cylinders?

Started driving like a Grandma again to test that part of the theory, hard starts again.

What do you think??

Injuneer

When the engine finally starts, and is idling (possibly elevated idle due to cold coolant), what does the volt meter on the dash read? Typically the voltage regulator increases the system voltage upwards (around 16 volts), to allow the alternator to replace the battery capacity used to start the engine. Is that happening?

Not sure what the reference to the LT4 on a stock tune means. Didn’t see anything about that mentioned above, or did I miss it?

By “slow start” are you saying the starter is cranking the engine slowly, or do you mean the starter is OK, but the cranking time is extended? If the latter, you try putting the accel pedal on the floor to put the ECM in “clear flood mode”?

Gtpguy

Pretty much dead center, 13. With A/c and radio off VERY slightly more than 13. When it slowly cranks it's around 8 then as the engine turns on still at 8 briefly and rests at 13. Never seen above it like the 16v you mentioned.

When it starts slow it hesitates between rotations it feels. Like it's about to be a dead battery but finally catches and starts. Rr.......Rr........Rr......Rr Rr..START. <----crude description. Unlike a normal start sound...RrRrRrSTART!

Injuneer

The voltage regulator is in the alternator. Have the alternator tested (interestingly, GM still calls it a generator). Somewhere in the back of my mind, I think the 93 might have had a 130-amp alternator, while later years had a 140-amp. Not sure…. 30 years of LT1’s has taken a toll on my memory.

shoebox

The 1993 alt/generator was 124A, but you were close! I did have to verify with the manual .

Injuneer

Thanks! I need all the help I can get . I looked in the 4th Gen FAQ but couldn’t find it.