93 C4 Bogging out please help

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Oct 11, 2004 | 10:50 AM

nolan1123

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From: PA

93 C4 Bogging out please help

I did post this under the general disscution C4 board. And got some very good advice. wich i appriciate.

But i thought i would post over here to im sorry if posting the same thing on different boards is wrong.
but anyway here is my problem.

A few days ago I was driving my C4 automatic with 65,000 miles on it ,and I really layed on it, basically Floored it. So i had my fun and coasted back down to normal throttle. Then i gently accelerated again to get up a hill and the car bogged out let me try and explain. It was like a hesitation or a Jerk. Almost like it had missed a gear or something. It only did it for like 1 sec and that was it. But know im affraid to floor it again. did any of you ever get some bad fuel with maybe some water in it, and the car hesitates? was something like that to.
Any help on what i should do, Or buy some feul injection cleaner or any other stuff like that.
Also some times when i start the car and put it in reverse it sounds like its going to stall out, and sometimes it idles funny
thanks
Bruce

Oct 11, 2004 | 11:03 AM

rick lambert

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From: seattle WA

I think I would try some injector cleaner-I'm an advocate for Seafoam.

Oct 11, 2004 | 01:19 PM

bogus

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From: San Pedro CA

lets talk basics here.... the plugs are a good cause for this bogging, it's a miss, actually.

Are they original? If so, they must be replaced, and NOW. You see, the OE ACDelco Platinums are junk... the ground strap has this little platinum plug on it. Over time, it erodes/falls off and will cause the gap to grow from .050 to .065!!!

I recommend NGK or Denso.

Another cause of this is a weak coil. Check the coil wire, the coil itself and the ignition module (driver). The coil is behind the power steering pump, the module, under it.

Check the plug wires. You may have a burnt one.

Check the throttle body. It may be gummed up.

I am not a fan of adding cleaners to the gas. Those chemicals are very harsh and can harm the factory injectors. I am a firm believer in good quality gas (ExxonMobil, Chevron, Citgo, Texico, Sunoco) and regular driving.

Seafoam is cool stuff. Poor it into the intake via the power brake booster. Cleans carbon deposits off the valves and such.

Good luck!

Oct 11, 2004 | 04:10 PM

QuikZilver

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From: Delray Beach FL

I agree with Bogus. I had the same problem on my 93 when I owned it. I replaced the plugs, wires and coil. I also replaced the fuel filter, as it had been a while since it had been replaced. With mine, the coil was going bad when the engine was hot and would cause a miss. When the motor was cooler, the motor still didn't like to have the hammer laid down on it. I looked at the factory plugs (all but 2 were missing the platinum pucks, so the gap was WAY out). I replaced the plugs and while I was at it, did the wires. After that, I could hammer it and it would go. Of course, it wouldn't go like my Z...but, hey, it was still quick.

Oct 11, 2004 | 06:59 PM

nolan1123

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From: PA

thanks everybody for the info i will be checking them out
as for the seafoam, can someone please tell me exacly where the seafoam goes into. a pic would be nice. sorry for the newbi stuff but im just trying to learn from all you experts.

Also i dont know if this is normal but when im keeping the accelerator going about 40mph to 43mph the car vibrates real bad but only somewhere inbetween those MPH's if a accelerate a little more it comes out of that and is fine.

Also anyone know how to replace the lights behing the spedometer. My oil temp light is out.
Thanks
Bruce

Oct 11, 2004 | 07:27 PM

mikey whipreck

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Quote:

Originally Posted by nolan1123

Also anyone know how to replace the lights behing the spedometer. My oil temp light is out.
Thanks
Bruce

theres a tech tip on this site that tells you step by step how to do that...

as for the vibration, my first guess would be alignment.

Oct 11, 2004 | 07:31 PM

nolan1123

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From: PA

the vibration has done it since i bought the vette, it only 10,000 mile on it with only one previous owner. its not an alignment thing its more like an engine vibration almost like its inbetween gears. It is an automatic by the way
Thanks
Bruce

Oct 11, 2004 | 07:41 PM

Lone Ranger

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If you do all the things already mentioned, which are good things to check, and it still does it, consider replacing the MAP sensor (especially on a Speed Density car i.e. your '93). Or at least have the MAP sensor tested for proper function. MAP = Manifold Absolute Pressure.

The MAP sensor readings are vital to spark advance, spark/knock retard computations in the PCM. And that's just in MAF cars. In a Speed Density car like your '93 the MAP sensor readings are also vital to injector pulse width computations in addition to spark advance and retard computations.

So one can see how a faulty or glitchy $30 MAP sensor can effect performance...

Last edited by Lone Ranger; Oct 11, 2004 at 07:44 PM.