Surging, irregular idle, random no power on accelaration

[freshtiva]

People with no skills can replace a thermostat.. blindfolded.

[frogman]

I always check the easy stuff first. Look the Distributor cap for cracks and tracks from spark jumping. Take the cap off and check the inside for the same.
Look carefully at the center carbon coil wire contact. It may be missing, worn out or pitted.
Next, check the rotor for the same. Pull it off and spray the center with brake cleaner and then wipe it with a clean rag. May take several times to get the carbon all off. You can sandpaper the tip lightly to clean it up.
The carbon build-up shorts out/draws a lot of voltage and amps that the coil is trying to send to the plugs.
Sometimes a dead battery cell will do the same thing. Have an Autozone or other parts store check your battery and alternator, on the vehicle.
This type of problem happens most often when the first cold or hot spell hits.
don't know why other than there is more draw on the battery from running the heat or A/C.
Hope you already have the problem fixed and that it was cheap and easy to do.
Have a Merry Christmas a Happy Festiva(s) New Year.

[Kofkof_00]

Thanks frogman,

Dist cap is new, it's been checked, rotor is new, plugs are new, plug leads are new, battery is new (optima bluetop) Engine has just recently been through a complete rebuild.

Fresh, I was at work, I dropped it off at the station, figured I would get 1 hr labor, max. Instead I'm buying his daughter an new Ipod for xmas. Oh well, live and learn. Not going back there again.

As I'm now broke, and I think i've stimulated the automotive industry enough, I'm going to attempt changing the TPS and my fuel filter over the holidays...

[Kofkof_00]

Changed TPS, took it out for a spin. Still not sure.

I'm going to try to go for a longer drive. (try to go somewhere with a goal) See If I can get it to fail.

[Kofkof_00]

OK, changed the coil also, for good measure. The car no longer has the intermittent miss. It was a very faint symptom.

I'm due for a sunroof install this week. Going to drive it all that day & see. Hopefully this is it, and it's fixed. If it is, i'll document it here.

[Kofkof_00]

Just replaced the alternator with a 70 amp one. Car feels much better. (I'm hoping this was it!)

[leapin]

Whats the Alt from?

[Kofkof_00]

From a 1990 mazda mvp. 70 amps & I had to get a longer lower bolt.

Alas. Not it. I did it on the highway tonight. *cries*

[leapin]

Have you tried a jy VAF/MAF yet? Im still leaning towards that. Im gonna show a tech friend of mine at work this thread. See if we can brainstorm some ideas.

[Kofkof_00]

nope, haven't tried the maf/vaf... it's in the works.

[Claude]

dude i was having the exact same problem, my car would stall kind of and jerk back when pressing on the gas and it made me very upset to say the least, i read everyones threads and answers and tried everything they said and even went and bought a replacement fuel pump from someone on the sight, replaced the filter and still had the issue. then I decided to look into something simpler, crud in the engine, which was my problem. I drained my fuel tank and manually put my hand down there and scraped off the loos rust, dirt, crud that was floating around, causing the car to sputter. Im not sure if this is your problem but it cant hurt to check, also dont overlook the little things cause more often than not its something simple and you end up wasting a bunch of money, dont worry I did too.hope this helps..

[JohnGunn]

What I would do.

also dont overlook the little things cause more often than not its something simple and you end up wasting a bunch of money, dont worry I did too.

So did I.

I had a slightly surging idle and a pronounced surging when I went from accelerating to holding a level speed. Trusting my expensive Bosch Fusion spark plugs, I turned my suspicion on everything else, including, as have you, emission control devices, all at great expense and bother. Finally, in desperation, I replaced my expensive plugs with much cheaper NGK V-Power plugs and problem solved.

Sounds like you are having some of your work done by others. The problem with that is you are left having to trust they did their work well and, of course, that will not always be the case. I found the NGK plugs, out of the box, all set to different gaps. Do this yourself: Gap the plugs with a wire style gauge so that the slight resistance you feel as you pull the wire through the gap is "exactly" the same for all plugs. I set mine to .044". Then carefully torque them in, using some anti-seize compound.

Nothing is more crucial to smooth driveability than properly functioning spark plugs. Since you've been through just about every thing, it may be time to go back and make sure you have that most crucial factor well covered.

John Gunn
Coronado, CA

[Kofkof_00]

the fuel filter was inspected, and it was clean, so the crud isn't the culprit. (I still have a brand new one, just in case) The plugs are NGK's fresh from the engine rebuild.

I just did some electrical grounding work, often referred to as "the big three". I also ordered a different voltage isolator (I run dual batteries) I kept seeing my 500mfhds cap slowly draining the rear battery. It got pretty annoying, and I disconnected it. (booo no more bass bin for now.)

So post new ground strap & stuff, I took the car out. (I drive in circles around my house until the symptoms re-occur) Surprise surprise, no stuttering. (Yet... I'm going to try driving longer tomorrow)

Could the combination of a cap, trying to charge itself continually, have messed with my voltage isolator? It's one of the solid state models that only allows current to flow one way, and intelligently (or dumbly in this case) tries to charge battery # 2.

Maybe someone here knows how to test both a stereo cap and an RV voltage isolator?

[grey]

the fuel filter was inspected, and it was clean, so the crud isn't the culprit. (I still have a brand new one, just in case) The plugs are NGK's fresh from the engine rebuild.


Maybe someone here knows how to test both a stereo cap and an RV voltage isolator?

first, the guy was saying that inside the gas tank there is another "filter"
and sometimes it will be cause intermitten problem such as you have.

the second thing, i would check this by disconnecting all of it.... and see if that helps. You may have to isolate (shield) some wires or something

I suspect engine coolant sensor since I did not see it checked.

[bakerga1969]

Spark plugs worn or not gapped properly,plug wires,vacuum leaks,faulty coil,uneven or low compression,faulty fuel injectors.