I saw on a form that surging idle with a volt meter that surges with the rpm gauge exactly could be a voltage regulator...

Im trying to get down to the bottom of my surging problem and i havent gotten anywhere and then i came accross that which is the EXACT same problem im having...

So can a voltage regulator being bad cause a surging idle and how?

Thanks

 

When you say "surging" problem, is it when the car is sitting idle, or running at a stop, or after it is warmed up, when it is first started and cold?

 

No.

You've got the cause and the symptom mixed up. As did whoever wrote that humorous thing about the voltage making the idle surge. That's pretty funny. consider it "entertainment", but not "technical".

The voltage is changing because the engine RPM is going up and down; not the other way around.

Clean your IAC. Leave the alternator alone.

 

He has a carb> no iac

 

Maybe... hard to be sure...

The symptom he describes goes with fuel injection.

Look at his profile.

Maybe he has 2 cars.

Maybe he should tell us that himself.

 

I have an 89 Iroc 5.7 TPI ICA is bran new, TPS is ajusted and had no dead spots, just did a tune up yesterday and the plugs were all covered in carbon, Ajusted min air accor5ding to the tech article, no codes, New MAF Good relays

The one thing i did notive is that when i unplug my o2 sensor it dosent change or throw a code...

And the surging is at idle in park or N and in Drive idling at a stop or even cruzing when rpms are 1500 or less

Sounds like detonation causing the surge so air fuel because i know it running on all 8 and my shop teacher verified.

And its on when its warm when its cold it runs like a champ then when it trys to idle down at about 160* it start surging.

Anything else. Thanks for the help!

 

Check your fuel pressure. Could be a fuel pump issue or a fuel pressure regulator problem.

 

i check fuel pressure when it was in open loop mode and it was 40 psi but the car dosent start surging untill closed loop so i need to check fuel pressure when it surges to see... O2 sensor check good and the pc is reading it .2 to .6 .2 to .6 ect ect and the car switches from rich to lean mode very fast...

BLMs are 109 to 128

What are BLMs any ways..

 

BLM=Block Learn Mode

Basically it's a rough indication of air/fuel ratio via the O2 Sensor. 128 is great, 109 is on the rich side. Switching from Lean to Rich very fast while in closed loop is normal.

 

alright sounds good i also found i had a code 13 it come up while driving on the freeway then went away but it was saved in my ecm. o2 lean at cruse i beleave i cant find a code list but im sure thats what it is.

 

 

 

Help, my 1989 Firebird, 350 TPI rpm's rev up and down when i start the car, then levels off when car gets warm. What is the problem? I installed plugs, wires, rotor, cap, ignition coil and it runs better, but still rev's RPM's when I start it in the morning. Some guy told me my MAF may be bad. i know plug number 3 has gas when I removed it. it has new fuel pump. It also hesitates from a standing start. kinda of shakes also.

 

Check your grounds. Battery, back of heads, block.