Odd behavior from my car

[Sully008]

Hey all,

I've noticed this before with my car, and now I'm starting to wonder about it. My car has a "Jekkyl and Hyde" complex. When I start it up it either:

A. The starter turns the engine over right away and the engine roars to life with the appropriate exhaust roar.
or
B. The starter cranks for a second to and the engine barely makes a sound and not much from the exhaust.

When it starts like A, the car feels like an animal. The engine and tranny are very responsive, and it feels strong.

When it starts like B, it's pretty much the opposite. It feels gutless and the shifting feels sloppy.

I have no idea why it does this. There is no rhyme or reason as to when it does it as well. I've had it happen when it's been warm/cold/wet/dry. Sometimes it'll start weak, I'll shut it off and restart and it'll roar to life.:confused:

My few mods are in my sig, with the inclusion of the GMS COP wires, which BTW, made the idle much smoother now. Anybody have a guess as to why my car does this?

[Blackened300a]

My car does the same exact thing. Every once and a while it would crank and not start, or it would start at a lower RPM when it ignites Other times I would start it and it would roar to life without a prob.
I was thinking it may be the gas I have in the tank may be crappy, or I just raced with less then a 1/4 of a tank and I pulled a lot of crap up from the bottom of my tank. :rolleyes:

[Marauder.45]

I get weak starts on occasion as well. Almost stalls.

It's okay after that.

[Motorhead350]

I was guessing your start up problem could be your alternator, but that wouldn't explain why it doesn't always run right. Sorry I can't help you here. :alone:

[gilby04]

My car does the same exact thing. Every once and a while it would crank and not start, or it would start at a lower RPM when it ignites Other times I would start it and it would roar to life without a prob.
I was thinking it may be the gas I have in the tank may be crappy, or I just raced with less then a 1/4 of a tank and I pulled a lot of crap up from the bottom of my tank. :rolleyes:

My car usually "roars to life" on start-up and initially revs to 1500 RPM. However, there's been several random start-up occasions when it starts with a "weak moan", revving to 1000 RPM maximum. These random occasions tend to be those immediately following a mile or mile & a half run to the corner store when the engine has not attained normal operating temperature.
There was one occasion this past winter that was quite odd. I backed the MM out of the garage in order to have more room in the garage to wash my wife's car. About 30 minutes later I turned the key to start and...no roar, no rev, no starter engagement, just a high pitch whining sound. After several more unsuccessful attempts at starting, I thought I'd try just one time before phoning the dealer, and abra- cadabra, it magically starts, but with the wimpy "weak moan". I drove it around the neighborhood until it warmed up to the normal operating temperature, shut it off in the driveway, waited a few minutes, and restarted it. I was very happy to hear the familar "roar to life" sound once again. And it hasn't happened since !
Lastly, in my case, I always maintain a minimum of 1/2 of a tank of gas, so I can't report that fuel quantity in the tank is an active ingredient in my start-up variations. It will be interesting to note & correlate the fuel quantity in the tank in future occurrences, if any, of the "weak moan" start.

[Marauder.45]

Varying gas amounts in mine. From full to 1/4 tank.

[hotride03]

Yeah, mine does somewhat the same thing once-in-awhile. it makes a buzzing kind of noise. but, it runs strong other wise!

[DirtyDog]

See if this rings a bell. You come home from work, park the car for the night, next morning starts likr normal and off to work. Everything fine all week long. Friday night you come home park car out side. Go get something to eat, car cools off. You go back out and wash the car. Start it up, run it for a few minutes, drive it into the garage and shut it off. Next day you go start the car to go somewhere and it starts poorly and takes about 4 minutes to get going like it should. ####It did not have time to cycle through all of the things it wanted to do before you shut it off the night before and it was confused.

[gilby04]

See if this rings a bell. You come home from work, park the car for the night, next morning starts likr normal and off to work. Everything fine all week long. Friday night you come home park car out side. Go get something to eat, car cools off. You go back out and wash the car. Start it up, run it for a few minutes, drive it into the garage and shut it off. Next day you go start the car to go somewhere and it starts poorly and takes about 4 minutes to get going like it should. ####It did not have time to cycle through all of the things it wanted to do before you shut it off the night before and it was confused.

I think maybe your confusion theory deserves consideration.
I wonder if it's possible that a brief duty cycle could "load up" the fuel rails, sort of speak, and cause a stumble condition on the next start-up.

[DirtyDog]

I think maybe your confusion theory deserves consideration.
I wonder if it's possible that a brief duty cycle could "load up" the fuel rails, sort of speak, and cause a stumble condition on the next start-up.


That's it, I thought my explaination would make it easier to relate to.

[RF Overlord]

Similar thing happened to me in December. Below freezing, had to move the car to the neighbour's driveway across the street to make room for the roofer's vehicles. Then had to move the car to the other neighbour's yard for the night. When I retrieved the car the second night, it cranked but wouldn't start until I held the pedal to the floor, then it started but ran rough. Drove it around the block a couple of times and it was fine. Hasn't done it since. I don't usually start my cars for brief intervals like that so I also lean toward DirtyDog's confusion theory.

[Sully008]

Hey all,

Hmm...so at least I'm not the only one having this weird phenomenon. Like the rest of you, there is no rhyme or reason for it. But the confusion theory is interesting. Does the ECU need some sort of "cycle time"? It is the first I've heard of such a thing. I hope I don't go into battle with the "Mr.Hyde" car one day.

[LVMarauder]

same thing has happened to me. I dont drive mine every day but at least twice a week and I get that all the time. It bothers me , I turn the car off and start it again end it sounds normal and revs to 1800 just so everyone around me knows what its supposed to sound like. If anyone has a fix let me know.

[TripleTransAm]

I reported on this a while back in a thread discussing blue smoke at startup, with instructions on how to repeat it... sounds like similar if not identical symptoms.

Appears to be normal for the Marauder's (dirty) cold startup routine. However, on my stock MMs, I really needed 3 or 4 short starts in a row to get this to happen. Perhaps it has something to do with a chip or aftermarket tuning?

None of my other FI'ed cars have ever done this, by the way, so I wouldn't blame this on fuel injection in general. When my '78 and WS6 were jockeying for one garage spot at my old house (with the Honda in the way all the time), the WS6 never acted any differently no matter how short the operation time. Same for my GTA way back when I'd pull it out of the garage to wash it, back in for a half-day of detailing, back out for a wipe down, back in for the night, and out for the trip to the car show the next day.

Maybe this is related to the flaky IACs we seem to be stuck with? ie. if it stays stuck too closed, you can't get that 1800 RPM startup?

[sweetair]

I'm not gald to see that others have experienced this as well. But it is comforting to know that I am not alone. I noticed this ever since the blower install over a year ago. Every now and then there is a weak start. Sometimes a idle to only 1000 and sometimes I am not sure after it cranks that engine has engaged, there will be silence, and then it revs to the 1000 mark and settles in. I have never restarted. It seemed fine once it got to idle. I bent a pin in my CPU and straightened it w/a needle nose pliers. I have spoken to Lidio and he agrees that not all pins are "live" in the computer. He feels that my computer is fine and had no explanation for the weak start. It hasn't happened in a while. The car not running for enough time is an interesting theory though.