Help please

Hi! My husband is also a member on this site. I just thought that maybe I should try as well. I am looking for a data link port for a 95 Buick Riviera. Does anybody know where I can get one from? Please? I love my car!
Thanks for any help. -Befuddled

Do you mean the diagnostic port in the driver's side foot well?

JR, I think you tried to answer a Troll.

If Not, TOO STUPID to understand.

Rickw wrote:

JR, I think you tried to answer a Troll.

If Not, TOO STUPID to understand.

Perhaps...

For the rest of you reading this in the future, problem with the 95 Riv is it had an OBD-2 type data link connector but the car was set up for OBD-1.  Best way to get at the diagnostics on this car is to get an old GM Tech I (not tech II) tool.  A Tech II will work as well with the correct dongle.  There were other scan tools that had adapters also, I don't know much about them except to say that you might find them used, and they are generally discontinued and unsupported.  A thorough search of this web site will yield names and model numbers etc. of the tools that will work.

Rickw wrote:

JR, I think you tried to answer a Troll.

If Not, TOO STUPID to understand.

This is an odd place to be trolling, but I suppose anything is possible.

Daughters 95 SC Riv. codes P0321 spark ref circuit, P1361 control sig not toggling intermittent stumbling.

replaced coils, cam / crank sensors recently due to hard start problem. Then the ignition coil quit - no start. Replaced again. This code problem started after I replaced fuel pump & FPR for hard Starting.

Starts well now, but throws codes.

Disgusted.

redbaron wrote:

Daughters 95 SC Riv. codes P0321 spark ref circuit, P1361 control sig not toggling intermittent stumbling.

replaced coils, cam / crank sensors recently due to hard start problem. Then the ignition coil quit - no start. Replaced again.  This code problem started after I replaced fuel pump & FPR for hard Starting.

Starts well now, but throws codes.

Disgusted.

This should be its own thread... that said...

what are you using for a scan tool on the '95? Reason I ask is, if you're not using a tool that reads OBD I thru the OBD II port, you don't get the correct codes.

So, just curious.

IF you are losing ignition coils you need to check the engine grounds, the ignition module and its grounds, and the plug wires. If you have bad plug wires you will kill the coils the baddies are connected to (in a hurry). All that spark energy has no place to go and the coils fail internally.

It could be that the coils frying took out the ignition module. You will need to consider replacing it. You can try simply removing, cleaning and reinstalling it. When you do you will need either dielectric or conductive grease to smear on the ground plates after you clean them and before you reassemble. a BIG headache with these things "back in the day" was basically crappy grounding at the Ig module. I replaced my ig module probably 15 years ago.

The hard starting you had may have been the ig module all along; if the ig module is not working right, the PCM can't set timing correctly and the car becomes hard to start (been there done that and it took a while to figure out). On the Riv, the teeth on the reluctor wheel by the crank sensor are keyed so that if everything is working right the car can start in 120 degrees or so of cranking. This is explained in the service manual (a copy of which you will really want to have in order to keep this car as any sort of daily driver -- IIRC for the 95 it is a 2-volume set - check eBay).

See this thread for insights. https://www.gmforum.com/1992-1999-91/random-misfires-code-p0321-283788/

So... my current *guess* is you need to check the ignition wires (with ohmmeter and visual/physical) and see if any are bad. You already know to look in the ends for frayed or broken center conductors, and to check the end terminals to be sure they actually clip the contacts on the plugs and coils. I had one problem caused by a terminal that had actually ablated into a plasma - yeah it vanished - so it would make-and-break and killed off the coil.

For the ignition module, they are not free but neither are they too much $. I would start by cleaning it.

You might want to use an ohmmeter to see that the primaries on all the coils have the same resistance, as well as the secondaries. If they don't match the engine will lope or worse.

Another possible problem is the replaced crank sensor. The WVE, Delphi, or NTK sensors are much better than say the Standard t-series for instance. You can not cheap out on that part.

Another problem could be the wiring to the ignition module. Check for conductors that are broken inside the insulation, right at the connector to the module.

That's all I can think of ATM. You need a manual set.

Albertj

Thank you Albert

This is an obd 1.5 so a friend with snap on scanner had to read the codes for me.
I have a set of plugs and wires. will try first
I have another ICM, will do 2nd along with measuring coil ohms. All are new but I believe 1 is different mfr.
I just got factory a manual from ebay
3 weeks ago I learned the crank trigger signal goes through the ICM by tracing and ringing the wires.
thats when I changed the ICM and got it running again,

youv'e been a major help to me, I can't thank you enough.
will keep you posted Brother

Also Grounds are solid.

redbaron wrote:

Also Grounds are solid.

You are welcome for the help, hope you solve this soon.

Word to the wise if you personally did not remove the ignition module and check/clean the ground plate, do it anyway. One problem can be a technician will slather on dielectric grease. You can't do that, dielectric grease is an insulator and is not all that compressible. As you know the point of using it is just to seal air away from cleaned metal surfaces. It gets squeezed away but still seals around the points that do make contact. Too much, and it insulates (like it's supposed to).

As for the grounds, there is a recent SAE paper about ground connections developing a capacitance due to corrosion. They will test good with a continuity checker and show a very very small resistance with an ohmmeter; a capacitance meter will measure a small capacitance. However, in electronic ignition systems with their fast pulses, that small capacitance is a huuuuuge problem, W/o going into details it's a 'thing' now because of current less expensive materials being widely used in connectors the past many years. People keeping their cars longer, this is showing up more and more, mostly as random phantom misfires that nobody can figure out because, well, capacitance in ground connections? What?

I could not confirm that the '96 SC riv with the Series I engine used a different coil than the NA version. On the 97 and later, they do - the Delco D576. They are still available new but are not cheap new. Rockauto.com shows them for like $42.- each or some such. Those coils are the high water mark for sure. 2 of mine are original and they still work fine after ~25 years and 400+ thou miles. One blew b/c I had a Delco ignition wire die. I did not know ablation of the terminals was a thing, hadda happen a second time for me to figure that one out. If for whatever reason you want a set of the higher energy coils, seriously, just find a pick and pull that has a Park Ave or Regal or Monte Carlo with the Series II or Series III SC engine and pull them They won't be $40 that's for sure and odds are they will work fine - you could take a pocket meter and ohm them out in the yard if you want to be sure before you part with your hard-earned.

Congrats on getting that manual set, you'll avoid a lot of headaches.

When you are messing with the wires be sure to look and poke in them to find out if the terminals are OK. You look up in there and all you see is rubber, you have a bad terminal even if it is working.

Also - I forgot to mention that some technicians tend to not really connect the rear bank of wires correctly to the plugs. Sometimes. Just saying. If somebody other than you was back there troubleshooting you really oughta check the plug wire connections at all the plugs as well as at all the coils. You find a coil end that is ablated or loose, you may have also found a bad coil - they don't last real long running open circuit.

You didn't mention checking for busted conductors in the wires to the ig module at the connector. No kidding that is a thing and as long as you are in there you oughta/should humor yourself and wiggle them. 'Specially since you had a bum ICM you just replaced - I'd be wondering a little about root causes.

Best,

Albertj

Hi Albert,

Today we
ohmed new coils same
Replaced plugs and wires - old looked to be in good condition
Replaced ICM- Inspected / tightened some female connections including the one by the alternator.
But I probably did apply too much thermal grease. I thought the intent was to draw heat.
I guess Ill clean it off and start over.
The engine still sounds like it has a very slight miss. Fuel economy on this one has always been poor.
Makes sense if it truly is missing .
Have to clean ground connections better to

You are correct about different coils on the 97s not same assembly

I guess Ill battle again next weekend.

Thank you

redbaron wrote:

Hi Albert,

Today we
ohmed new coils same
Replaced plugs and wires - old looked to be in good condition
Replaced ICM- Inspected / tightened some female connections including the one by the alternator.
But I probably did apply too much thermal grease.  I thought the intent was to draw heat.
I guess Ill clean it off and start over.
The engine still sounds like it has a very slight miss. Fuel economy on this one has always been poor.
Makes sense if it truly is missing .
Have to clean ground  connections better to

You are correct about different coils on the 97s not same assembly

I guess Ill battle again next weekend.

Thank you

I understand about the grease.  Think of it this way - due to the engine, that whole engine compartment is gonna be heat-soaked when engine is fully warm and operating at steady state.  Question is, can you get rid of the excess heat of the electronics as well.  What gets you on that ground plate is corrosion.  A thin, even layer of dielectric or heat sink grease will do it.   Most mechanics I know for some reason use dielectric (the clear dimethylpolysiloxane snot).  I do not see why a thermal grease would not work but no journeyman mechanic I've asked has used it on that ground plane.  In any event, you're looking for a thin even coat so the ground doesn't corrode.

One thing about the Gm 3800 (my dad called it the Whiskey Six although it isn't really - that was the six cylinder engine made by the Studebaker Automobile Company during the mid-1920s) - it essentially is a 90* v8 that is missing 2 cylinders and modified  to make up the loss, and naturally are rougher running than say the Buick 300 CID v8 they were based on (or IMHO any American V8 with an across-plane crankshaft).  

You have a slight miss with poor fuel economy?  Fuel economy on the 3800 in city stop and go driving is, well, horrid. 19 city is claimed but I am not aware of any list members actually getting that in city driving. Around hilly Pittsburgh for instance, I measured 14-15 MPG. On the highway, as long as I burn premium and don't walk rice boys on the interstate, high 20s low 30s is normal for me on long trips. Sooooo...   If you have slight miss and sucky fuel mileage on the highway, I'd be looking at the MAP (checking for vacuum leaks actually) and MAF (pull it and clean it with MAF cleaner nothing else) to start.  At idle, for trying to fix that miss I'd first be cleaning the throttle body especially the idle air circuit and the IAC solenoid to see if the car's  mood improves.

Albert,

Good news.

I found the root cause.
I noticed a very slight vacuum leak on the throttle body egr tube.

This tube looked new and bots were tight, but I disassembled anyway.
I found no gaskets on either end.... no seal! It must have been changing with temp. Especially when the egr opened...

Was previously not familiar with this supercharger egr tube so I Blanked both ends and unplugged the egr.

I can't believe the check engine codes were making me chase my tail.
Bottom Line - Don't believe all codes are legitimate.

In any case, I am much appreciative of your help and support.

Thank you
Joe

Is the "slight miss" gone?

I thought I might have a "slight miss," but when I looked up the symptoms of a miss it said there would be a definite fuel smell to the exhaust from the unburned gas. My exhaust smells llike normal exhaust. There's just a slight random "puff" that doesn't seem like it should be there.

Jack the R wrote:

Is the "slight miss" gone?

I thought I might have a "slight miss," but when I looked up the symptoms of a miss it said there would be a definite fuel smell to the exhaust from the unburned gas.  My exhaust smells llike normal exhaust.  There's just a slight random "puff"  that doesn't seem like it should be there.  

OBD2 has a misfire counter by cylinder. Unburned fuel in the exhaust will overheat and kill the catalytic converter.

Yes,
Slight miss at idle is gone.

A stumbling was most noticeable under light throttle up hill and would stall at times when stopping.

I also believe this was affecting the brake vac booster. Lower pedal at times. OK now.

Thank you

LARRY70GS wrote:

OBD2 has a misfire counter by cylinder.  Unburned fuel in the exhaust will overheat and kill the catalytic converter.

That's good to know. I don't have any codes.

I find new coils every 100K are needed on these 3.8s. Performance returns and fixes misfire problems.

redbaron wrote:

I find new coils every 100K are needed on these 3.8s.  Performance returns and fixes misfire problems.

Still on my original coils in my 98, with 207,000 miles and counting.

Ditto @ 140,000...

LARRY70GS wrote:

redbaron wrote:

I find new coils every 100K are needed on these 3.8s.  Performance returns and fixes misfire problems.

Still on my original coils in my 98, with 207,000 miles and counting.

Didn't the Riv get better coils than most other 3.8 cars?

redbaron wrote:

I find new coils every 100K are needed on these 3.8s.  Performance returns and fixes misfire problems.

Not my experience.

I have more than 400,000 miles on two of my coils; the third one I had to replace b/c a spark plug wire terminal ablated into oblivion.

Albertj

Jack the R wrote:

Didn't the Riv get better coils than most other 3.8 cars?

The NA rivs, no.

The SC Rivs, *definitely.*

Supercharged engines got a different coil. Cylinder pressure makes jumping the plug gap more difficult.