Annihilate

iTrader: (1)

Hey there guys.

Still haven't figured out all the ailments in my poor Camaro.

I'm curious as to how much vibration should be felt in neutral at varying RPMs? I understand this is a muscle car, a V8, and some vibration should be felt.

But what is the normal amount for a healthy engine? No mods, I replaced the harmonic balancer last season thinking this was part of the issue. While it needed to be replaced, it only helped a little.

I'm not sure if playing with the Proms have caused any issues, but all I've done is upload an 89 prom for my 88 305.

I do have Bosch 3 injectors from Southbay, but a test of all my injectors show they are working. However, when I remove the power from the back two passenger side injectors, there is no noticeable change in idle, vs the other 6 having a difference.

New spark plugs, wire, cap, rotor, coil.

I've tested with both a noid light, and an injector pulser to ensure its getting power and the injectors are firing. They also all ohm fine.

Really trying to get a smooth stock ride at this point. Many years and parts gone by and still no luck.

I also get vibration on the highway, but I'm not touching that again until I know it can rev in a healthy stable fashion. Im not sure about the condition of the motor mounts, but the car only has around 50,000 miles. Though I understand its quite old, and I do have a replacement set. I just know its not quite an easy job. Wanna make sure that's the problem before going into it.

Any input would be nice! Thanks!

Komet

Hmm, my (stock configuration) car is pretty smooth once it's warmed up.

Annihilate

iTrader: (1)

You can rev the car and not really feel much vibe inside?

Komet

Yeah, I wouldn't say it vibrates significantly, nor does it vibrate more at 5500rpm. I don't have significant vibrations on the road at legal speeds either. Air pressure starts doing some funny stuff with what's left of holding my dashpad on at about a buck twenty, allegedly.

I get the impression my car was driven fairly sedately before I got it and it has essentially a full tuneup with oem parts. I suppose you could try pulling all 8 spark plugs and compare their condition. Maybe do a compression / leakdown test see if a hole isn't bangalating correctly. With the plugs out, dip an inspection camera down in and have a look around.

vinny R

Well yeah!
With no load it should be smooth, if not you do have a problem.
1st I do not like Bosh3 injectors. You need a complete tune. If you uploaded a different tune that is a stock tune it will do nothing for those injectors. This could be your issue.
2nd If you are unplugging the 2 injectors and no change something is wrong also. You can try to drive the car with all injectors plugged in and then unplug the ones that don't make a difference and see if under load it makes a difference. Those injectors IIRC are remanned. I know Southbay tests them before they sell them but IMHO I would feel better buying new.
My buddy installed these same Bosch 3 injectors in his car and it ran really badly. We finally got the car tuned for those injectors and it runs good, but not great.

SbFormula

"I'm not sure if playing with the Proms have caused any issues, but all I've done is upload an 89 prom for my 88 305."

'89 BIN are $6E, '88 are $32B, both run on'7165 ecm

What BIN code did you have originally vs what BIN code do you have now? Was there any tuning done to them?

Thanks

Annihilate

iTrader: (1)

I was worried about the injector gig, as I've felt that was my problem.

Money has been tight. I also unfortunately feel my plug wires aren't the highest quality so I'm going to be dishing out some extra cash for that too.

As far as my bins go

The one that came with my car is AKFW 2423
I tried using a few bins from 89 but I was trying to use ANYX 9375

I attempted adjusting a few things such as pulse width and injector constant according to some posts on the forum related to these injectors, but that was about it.

What injectors are suggested?

vinny R

I used the Delphi's from Southbay. These are direct replacements for the stock Multecs that would have come on the car.

LAFireboyd

iTrader: (3)

No amount of vibration is considered normal or acceptable, IMO.

Camaro TPI Prom Identification Numbers - ThirdGen.Org
Firebird TPI Prom Identification Numbers - ThirdGen.Org

Based on the links above, for Camaro, 1989 PROM 9350 ANYS is the corresponding equivalent to your 1988 2423 AKFW. The data you're trying to use from 9375 ANYX is for the similar 89 Firebird.

You're doing this to eliminate the cold start injector? If still stock, then are there any other changes you're trying to account for, such as larger than 19# injectors, EGR, AIR?

Have you checked for any physical damage that might cause vibrations, such as motor mounts, transmission mount, driveshaft/u-joints?

Annihilate

iTrader: (1)

I've just read the 89 tune is the most optimized for the the 305 MAF so I wanted the updated information.

The cold start injector doesn't bother me either way, though I have a block off kit if I do need to rip off the plenum again.

EGR works fine.

The vibration im trying to work through first and foremost is in neutral, not moving, just vibration from the engine.

The trans mount is new. Motor Mounts look fine but I'm not quite certain what I'm looking for. The rubber appears to be intact and not cracked.

Annihilate

iTrader: (1)

Id like to know for sure if this was the issue before dishing out near $500 dollars for these puppies.

Almost would wanna do it just to eliminate the idea entirely.
But cash is tight.

vinny R

TGO members get 10% off from Southbay, I think they still honor this.
You can do a search on here for those Bosch 3s and see what others have experienced with those injectors. I don't think anyone experienced a plug and play with those. You can send the injectors back to Southbay and have them test them. Mark those 2 that showed no difference when you unplugged them. Sometimes injectors can OHM good but the spray pattern is not good or when hot they fail. If bad maybe they can credit you towards the Delphi's.
Data logging would be the best way to check. You would need some hardware, mainly a cable and a laptop. Guys that tune our cars will tell you there is an "injector Offset" and something else to change when using Bosh 3's. You can do a search in DIY Prom about this.

I looked at the parts you changed and did not see the ICM listed. Did you check this? Auto parts stores used to check these but not sure anymore. It controls the electronic spark advance. If this is not advancing the spark you would definitely get a vibration.

Annihilate

iTrader: (1)

Suppose it wouldn't hurt to try with Southbay.

I've done the tuning and data logging as best as I could in many different configurations with the Bosch 3s including the injector offset based off of as many different charts i could find.

I also did replace the ICM with This one paired with This coil.