84 dies w/a *pop*

[evolution]

Actually sounds more like a *PuP* but it happens at oddest of times. Bieng an auto, it is when the revs are low and I tap the gas to pass someone or drive over a speed bump. (note: It happens about once a day and is not very consistant with anything except low revs) Any ideas!?!

 

[Ken]

Welcome To The Corvette Action Center evolution!

Need more information. :confused

_ken

 

[evolution]

more info Hmmmm

Well aside from a SLIGHTLY rough idle it also seems to do this when it isnt warmed up completley (220). BTW I am going to install a hypertech stat and chip to aid in cooling. Supposedly it was tuned up before I got it but I am assuming that the "tuner" did not know what he was doing. It has a new intake man gasket, new distributor parts (cap rotor etc..), plugs, just passed smog, smog pump and computer. I might be looking at a break in current from the ignition to... something I dont know where it routes to right now, I just bought it for 4K about two weeks ago from my parents. It has 88K miles and has been pretty well maintained overlooking the fact that my mom forgot to bolt the top down and caused it to breakdance down the street one day.

 

[vigman]

Hmmmmm

It's a backfire through the intake, right?

Does it stall or just makes the noise?

Do you have access to a VAC gauge?

Measure the intake vacuume@idle.

Sorry about the top.

"my mom forgot to bolt the top down and caused it to breakdance down the street one day."

ROTFLMAO Had the same thing on my 73.

My girlfriend was resting her arm
(elbow on door sill, arm up, her finger in the foward release catch)
We hit a small bump.

EJECT-EJECT-EJECT.

Mike

 

[evolution]

Yah

It does sound like a backfire and someone told me it might be running rich. I almost forgot...new knock sensor too.

 

[evolution]

Double Oh Yeah

No no access to a vac guage and yes, it does stall out.
I just pop er in N and start back up.

I had a 78 chevy van for a while and the damn thing would stall in sort of the same way and it was the ignition-key-part-thingy (I just woke up). I really sucked cuz I would take a corner and *pop* there goes my power steering. After a few near collisions due to this I finally figured out what it was and I fixed it. Then a month later It wouldnt pass smog cuz I had fuelie heads and all sorts of non-smog fun crap on it. 600 bucks is all I got for it.. : (

Anywho, about the vette. Pretty much everything ignition wise was replaced on it when it failed to start up. That happened to be the pin for the dist gear. It would turn when the cap was off but not when it was on. That was several harrowing months of frustration.

 

[evolution]

as a matter of fact Vigman, you helped me on that issue. It was about 10 months ago. I told my dad right off that bat to replace the entire distributor assembly. But NoooOOOoo jaut had to plink part by part and several hundred dollars later....a $1 pin. lol

 

[vigman]

Hmmmmm

No trouble lights(ECM)
Buy a VAC gauge ( about 20 bucks )

Has the EGR been replaced?

Does the car desiel when you shut it off?

The dreaded POP can come from many areas.

Its a pre ignition in the intake.

Can come from
Bad timing
Valves not quite seated ( or HUGH deposits on intake side retaining heat), EGR leak, to much advance, streched cam chain, misfire in ign timing.

Can you make it happen with the car stopped in the driveway? By winging the engine?

We have to narrow things down a bit.

Do you have access to a timing light?

Check your coil again for poor connections.
( the ones under the cap going to the electrical connectors on the side CAREFULLY)

I assume the car has good power when it's not POPing.

Wires are in good condition.. not leaning against the exhaust manifold, burnt to a crisp.Do you have all the PROPER retainers installed

( bit of a stretch here)

The wires ( if they are old) are bundled together with tie wraps.. VERY CRUNCHY wires that are bundled
TIGHT will allow the spark to jump to a cylinder that was not ment to fire at that time.

Mike

 

[evolution]

You know, this only happens once in a blue moon so it seems that if it were any of the problems listed (exc. spark jump) I would think it would happen all of the time or at least more often than not. I dont think the timing can be that far off due to the faxt that it was just smogged. (1 month ago) It happens on average of about every 150 - 200 miles sometimes every 100

The EGR should be in proper operating condition and no, the car starts and shuts off fine.

It runs like a bat outta hell otherwise.

 

[David-F]

See if you can make it stall by getting it hot and just tipping the throttle, if you are able to get it to stall then try unhooking the EGR valve and trying again and see if it doesn't happen. You may also notise a slight loose of power just giving the car just a little throttle like creapping in a parking lot, again this is common if there is a problem with the EGR valve. But also make sure the EGR solenoid is pluged in if the connector comes out the vaccumn will go to the EGR as soon as you start to give it throttle because the solenoid is operated when it's turned off. But be real cerafull the connectors will be real brittle.

David Fulcher

 

[evolution]

Thanks David-F!

I tried it and the thing died out when I tapped on the throttle, well afted it idled down about a second later. I then bought a new EGR just for kicks cuz its right there, relativlet cheap and it was crappy looking. Unfortunatley it didnt solve anything. Do you suppose the solenoid is screwed?

 

[David-F]

It'a possible, see if you can blow air through the solenoid with the A to B terminal of the ALDL connector jumped and the key on this should ensrgize the solenoid and block off air flow through the solenoid, if it doesn't then there is a problem there. Also you need to take a look at the TPS setting try lowering it a little and see if it helps, spec. is 0.52 + or - 0.075 volts so if the TPS is above this the EGR will come on with a lower throttle opening and that is part of the problem. Now I have seen people install restrictors on the EGR vaccumn line to help get away from this but I feel if things are set up correctly and working as it should things should work correctly with out any need for this, but it is something to look into if you still are unable to find the problem. Also wear in throttle linkage and improper minidle air apeed set up could also cause a problem with getting the correct TPS set up and make the problem even worse. But let me know what way you want to try next and how you make out I'm sure we will be able to get it working.

David Fulcher