HomeHome  PortalPortal  CalendarCalendar  GalleryGallery  FAQFAQ  SearchSearch  RegisterRegister  Log in  

Share | 
 

 Engine always Pingy, 91 Custom Cruiser

View previous topic View next topic Go down 
AuthorMessage
OurCircuitMessSlobmodel



Posts : 8
Join date : 2017-12-25

PostSubject: Engine always Pingy, 91 Custom Cruiser   Mon Dec 25, 2017 9:58 pm

Having some trouble figuring out why my engine is pinging at part throttle. 1400-1600 rpm is worst.

It does this with every type of gas-with ethanol 87 being worst and no-ethanol 93 being best.

I've done some homework so there are a few things I can get out of the way, right away. I believe its because of the egr valve perhaps not opening enough. so, let me run through what I do know and have done so far....

Base timing is zero degrees as recommended. Engine was replaced two years ago and is a new GM Goodwrench L03 built to 1993 specs. All stock, except for A.I.R. pump delete.

EGR valve is new, engine does stumble when activated by hand.

The EGR valve is not a DELCO part, as they stopped making it some time ago.

Pre-install, on the bench, with a vacuum pump applied to the new valve, it does not activate, but when a small amount of air pressure is blown into the pintle(just blew into it with mouth/lung pressure), the valve opens up. That bit seems normal to me.

EGR solenoid energizes when hooked directly to car battery. When used with the EGR valve, the tone of the engine did change when energized. It didn't change as much as I thought, it didn't bog down and die, but there was a change.

With the diagnostic terminal shorted, the egr solenoid connector put out a solid 12 volts, and activates the egr solenoid as it should when it is plugged into the connector. It does click and allow air to pass through when energized. I don't think my problem is here.

I don't observe much EGR movement, in park, warmed up, and hand working the throttle. The book says I should be observing some movement, but somehow I have this feeling that that valve isn't accomplishing much while the engine is on. Any ideas?

I have everything but a vacuum gauge, but I think I will be getting one very soon because this has been driving me nuts for years now.
Back to top Go down
phantom 309

avatar

Posts : 5685
Join date : 2008-12-28
Age : 108

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 8:34 am

OurCircuitMessSlobmodel wrote:


Pre-install, on the bench, with a vacuum pump applied to the new valve, it does not activate, but when a small amount of air pressure is blown into the pintle(just blew into it with mouth/lung pressure), the valve opens up. That bit seems normal to me.

If it doesn't open on the bench with vacuum applied, it's NFG.

A simple quick check is to compress the diaphram which lifts the pindle off the seat,.keep it depressed and place your thumb over the vacuum port. The diaphragm should stay compressed until you remove your thumb from the port.  If you compress the diaphragm with the car idling  and the egr passages are clear of carbon dams it will stall.

In my experience with 305's pinging, it can be a few different things
Low fuel pressure
Slipped balancer ring
Plugged egr passages in intake
Bad ignition module.

Good luck
Back to top Go down
rauldelp

avatar

Posts : 75
Join date : 2015-05-27
Age : 34
Location : Hollywood, Florida, USA

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 9:26 am

[quote="phantom 309"]
OurCircuitMessSlobmodel wrote:

In my experience with 305's pinging, it can be a few different things
Low fuel pressure
Slipped balancer ring
Plugged egr passages in intake
Bad ignition module.

+1 on the slipped balancer ring. I advanced mine +4-5 degrees before getting the aldl scanner. Ran ok, but not much faster. When I put the scanner on finally it was apparently pinging like crazy (+20-30 points per second) at part throttle! Turns out my balancer ring had slipped around 5-6 degrees so I was actually giving it +10 or so. Once I reset the zero it got a lot better, but still pinged on 87e10 at part throttle. I ended up burning a new chip with more relaxed timing in the part load areas to fix it.

Of course this was ping that I couldn't really hear. If you're hearing it, you may be slipped much much further or something else has gone wrong in the list above.
Back to top Go down
Fred Kiehl

avatar

Posts : 4531
Join date : 2009-11-13
Age : 69
Location : Largo, FL 33774

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 9:29 am

Have you checked/replaced the knock sensor?

When was the last time you replaced the PCV valve?

The EGR valve should not do anything when pressure is applied to the inlet. It only operates with vacuum. It will never see pressure in the vacuum line of the engine. You can often get a loaner vacuum test kit from a local parts store.

If the problem is the same from the old engine to the new engine, check for any parts that did not get replaced in the swap. The wiring under the front of the engine may be deteriorated and causing some issues. The insulation is usually fused into a single mass with assorted wires running through it. The O2 sensor wire goes through that bundle.

I had a problem with what seemed like the engine stumbling/knocking/pinging at about 50 mph. It turned out to be the transmission. I put a bottle of anti-shudder (it really does exist) from NAPA, and the whole symptom went away.


Back to top Go down
OurCircuitMessSlobmodel



Posts : 8
Join date : 2017-12-25

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 9:31 am

phantom 309 wrote:
OurCircuitMessSlobmodel wrote:


Pre-install, on the bench, with a vacuum pump applied to the new valve, it does not activate, but when a small amount of air pressure is blown into the pintle(just blew into it with mouth/lung pressure), the valve opens up. That bit seems normal to me.

If it doesn't open on the bench with vacuum applied, it's NFG.

A simple quick check is to compress the diaphram which lifts the pindle off the seat,.keep it depressed and place your thumb over the vacuum port. The disphram should stay compressed until you remove your thumb from the port.  If you compress the diaphragm with the car idling  and the egr passages are clear of carbon dams it will stall.

In my experience with 305's pinging, it can be a few different things
Low fuel pressure
Slipped balancer ring
Plugged egr passages in intake
Bad ignition module.

Good luck
I've checked/replaced all of those too, except the ignition module. I hope its not that.

As far as the EGR, on the bench the manual says itll only hold vacuum if the car is running since its a positive backpressure. Thats why it opened when I blew into the pintle with the vacuum pump applied. My worry there is that the return spring might be too strong for it to open enough at 7-10" of vacuum the car makes, as the pump will pull 28"
Back to top Go down
Fred Kiehl

avatar

Posts : 4531
Join date : 2009-11-13
Age : 69
Location : Largo, FL 33774

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 9:37 am

The car should make at least 15 inches of vacuum, because it needs that to operate the brake assist.

Back to top Go down
OurCircuitMessSlobmodel



Posts : 8
Join date : 2017-12-25

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 9:41 am

Fred Kiehl wrote:
Have you checked/replaced the knock sensor?

When was the last time you replaced the PCV valve?

The EGR valve should not do anything when pressure is applied to the inlet. It only operates with vacuum. It will never see pressure in the vacuum line of the engine. You can often get a loaner vacuum test kit from a local parts store.

If the problem is the same from the old engine to the new engine, check for any parts that did not get replaced in the swap. The wiring under the front of the engine may be deteriorated and causing some issues. The insulation is usually fused into a single mass with assorted wires running through it. The O2 sensor wire goes through that bundle.

I had a problem with what seemed like the engine stumbling/knocking/pinging at about 50 mph. It turned out to be the transmission. I put a bottle of anti-shudder (it really does exist) from NAPA, and the whole symptom went away.



Ah Mr. Fred! I could never google stuff about a B body wagon without seeing your name pop up, Im glad you are here.

Yes, all of the sensors are new, as are PCV. I forgot to mention I'm not throwing any codes.

I did once have some gas bad enough that it pinged so loud that the computer finally pulled timing.

You say I should be getting 15" of vacuum? I fear I don't know what I'm getting at the moment.
Back to top Go down
phantom 309

avatar

Posts : 5685
Join date : 2008-12-28
Age : 108

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 1:10 pm

If a stock sbc is idling smoothly it will generate from 18-20 hg. Less as the throttle is opened under load.

The manual check i offered you will tell you if the diaphram is not corrupted, and the intake passages for the egr are not blocked.
Mr fred will definitely offer you lots of advice.

You mention you have been following the manual,..?   Then asking for advice here might be a moot point?

All the manuals i have give comprehensive advice and procedures to repair troubles.
Are you concerned the manual is incorrect?

You probably already know the egr should be hooked to ported vacuum,.?
Back to top Go down
OurCircuitMessSlobmodel



Posts : 8
Join date : 2017-12-25

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 2:03 pm

phantom 309 wrote:
If a stock sbc is idling smoothly it will generate from 18-20 hg. Less as the throttle is opened under load.

The manual check i offered you will tell you if the diaphram is not corrupted, and the intake passages for the egr are not blocked.
Mr fred will definitely offer you lots of advice.

You mention you have been following the manual,..?   Then asking for advice here might be a moot point?

All the manuals i have give comprehensive advice and procedures to repair troubles.
Are you concerned the manual is incorrect?

You probably already know the egr should be hooked to ported vacuum,.?

I definitely need a vacuum gauge and to go take readings everywhere.

Plus the whole unavailability of the correct GM Egr valve has me worried.

I'm not worried the manual is wrong, more worried it might be incomplete. I've followed it to the best of my abilities, and I think I need to start over.

It runs pretty well, actually. Its just the last thing I need to figure out, I wonder if I'm missing something, and I want to figure it out without throwing too many more parts at it (I know....why stop now Very Happy )

I had retarded the timing on 87e10 and the pings went away. That was a while ago. It was slow and carbony.

It seems like getting a TBI 305 to run right is like pulling teeth. I have owned many cars from different eras and by far, this thing has been the touchiest of them all. Something tells me that this should not be so.

Somebody else mentioned here, about changing the computer rom. I would LOVE to have a new EPROM chip for the car with the parameters changed to just get rid of the EGR forever. Get a new fuel mix table in there and to heck with this lean burn crap.
Back to top Go down
Fred Kiehl

avatar

Posts : 4531
Join date : 2009-11-13
Age : 69
Location : Largo, FL 33774

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 2:43 pm

If the LO3 is correct, and all of the sensors are good, the 305 should run properly without any effort. The LO3 and LO5 chips are different. you can run either, but it will be less efficient with the LO5 chip. If all of the sensors are new, I would concentrate on what is not. It may not be pinging. For the price, putting the trans fluid modifier is a possible easy fix. The trans shudder acts like the engine is pinging.

Try these for computer/chip development:

http://www.dynamicefi.com/

http://tbichips.com/
Back to top Go down
occ6.6



Posts : 34
Join date : 2016-01-05

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 9:53 pm

there are 2 types of egr valves used on these engines,negative backpressure & positive backpressure .the positive backpressure type requires very little exhaust preesure applied to pintle to close a very small valve.this allows vacuum to close or lift valve off its seat.low restriction exhaust systems ie; cat delete or freeflow muffler(s) is enough to affect it.engine should die out when valve is manually opened.if not ,like the others said plugged intake passages.also check your spark plugs for proper reach into the chamber,i had a 350 vortec that rattled no matter what you did checked the plugs & found out some wizard had put some in that were too short ,they didn't even have the electrode in the hole ,it was still in the threaded portion of the head.just another thought, does it use oil? if its burning it that will cause uncontrollable pinging too
Back to top Go down
OurCircuitMessSlobmodel



Posts : 8
Join date : 2017-12-25

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Tue Dec 26, 2017 11:12 pm

No, no oil use. The plugs I ordered from rock auto, and they were the right ones, no funny business I could see.

Before I continue, I need to measure my vacuum supply to the egr. I will probably rig up said gauge so I can see what the egr valve is getting as I drive.

I did decarbon the motor using water a week or so ago. The tap for the egr on the throttle body worked well to pull in the water, but when I attempted to pull water through the solenoid, it wouldnt pull any water at all, even working the throttle by hand.

Im wondering if a condition exists within the computer in which it activates the solenoid fine when in diagnostic mode, but doesn't work correctly cruising normally.

I can make the ping disappear completely by retarding the timing, so I think I am on the right track as far as localizing the problem.

I am also entertaining the idea of sloppy workmanship in my brand new GM goodwrench motor, with some pingy sounding internals achieving resonance around the 1500 rpm range. But the old, clapped out motor which leaked and burned oil, and had insane amounts of blow by sounded the same. Oddly the old junk engine got better hwy miles, even though the valley looked like somebody crammed a tray full of brownies in it, it was so gunked up.
Back to top Go down
phantom 309

avatar

Posts : 5685
Join date : 2008-12-28
Age : 108

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Wed Dec 27, 2017 1:24 pm

ecm controls the egr solenoid, dependant on coolant temp map, vss etc,etc,.. Buzzing the throttle by hand won't accomplish much, I'm not sure how well the pindle will fare in the egr solenoid ingesting a pile of water.?
Back to top Go down
OurCircuitMessSlobmodel



Posts : 8
Join date : 2017-12-25

PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   Wed Dec 27, 2017 2:36 pm

I was using the water as an impromptu vacuum guage, since the tubing i have is clear, its easy to tell if its pulling anything at all.

I didnt expect the solenoid to pull vacuum, snapping on the throttle, and it didnt, so I guess my test was a success.

But im with you phantom, i wouldnt expect the egr to activate running in park, but the manual says it can be tested that way. Ive never gotten that test to work as written.
Back to top Go down
Sponsored content




PostSubject: Re: Engine always Pingy, 91 Custom Cruiser   

Back to top Go down
 
Engine always Pingy, 91 Custom Cruiser
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» Minecraft 1.8 Vanilla Custom Recipes
» Custom Rank Title
» Custom Your Domain Name
» [Engine Remake][EN][RU] Free Heroes 2
» custom domain direct to forum.forumactif.com

Permissions in this forum:You cannot reply to topics in this forum
GM Longroof Forum :: Longroof Tech :: Exhaust and Emissions-
Jump to: