Engine "shaking" at idle.. running poorly

jacoats · #1 03-02-2004, 01:03 AM

Hello All,

I have been here several times and have always found the information very useful. My 97 is running poorly, and the exhaust smells rich when it is started. I just changed the plugs and wires and the problem remains. It is running almost as if a couple of plug wires were off it. No SES or Ck eng light is on. Anyone have any ideas? The car has 150K miles on it, but I love it (when it runs right) and I don't want to giive it up!

JCoats
Alexander NY

kentuckyjoe · #2 03-02-2004, 08:10 AM

My 97 smoked on start-up after a extended crank, turned out to be the fuel pressure regulator, I don’t know if this is your problem, but for 10 bucks, and no tools required other than taking the engine cover off, it worth a try.

Do like I did and give it that old hillbilly guess

Indy8 · #3 03-02-2004, 02:31 PM

Yes, replace FPR first. Sometimes new wires can still arc through the insulation against metal objects so be careful in the routing of them. I know it's tight around the coil pack area, but try not to overlap or bunch them up together. If you suspect a mis-fire, try pulling off one wire at a time while idling until you find the one(s) that don't seem to affect the smoothness of the engine. You won't get shocked if you stay away from the business end of the boot.

jacoats · #4 03-02-2004, 08:48 PM

Thanks guys, I have a little more info:

I took the car today to AutoZone as they will put a scanner on it and read stored codes free of charge. The SES light came on this morning, so I thought I would get the codes read. The codes that appeared were "Multiple Misfires" and O2 sensor. The Autozone guy said the O2 code was probably caused by the misfires. He suggested that the wires were not connected properly. Since I had the problem before I replaced the wires, I did not think that was the problem. I think it may be a bad coil pack. I plan on pulling the plug wires one at a time until I find two that have no effect. Hopefully, those two will be on the same pack. When I changed the plugs, I noticed that the 6 and 5 plugs were wet and oily while most of the other were dry. I am thinking that they are wet because they are not firing due to the pack. Any thoughts?

Thanks again..

JCoats

oldsdad · #5 03-02-2004, 10:43 PM

kentuckyjoe where are you buying the FPR for 10 bucks cheapest one I can find is at advance auto for 55.

Indy8 · #6 03-02-2004, 11:51 PM

Sounds like you're on the right track.

kentuckyjoe · #7 03-03-2004, 09:45 AM

sorry on that price, inside help, i guess that makes a difference

RobertHammen · #8 03-03-2004, 09:32 PM

$38 through my local Buick dealer for the genuine GM part :-)

jacoats · #9 03-06-2004, 09:43 AM

Well, I checked he spark at the front bank of plugs, and they all have good spark. This leads me to beleive that the coil packs are good, unless only one side of a pack is gone. Does that ever happen. What about the FPR? Where can I find it and what are the syptoms of a bad one?

Thanks agan for all your help!

JC

jacoats · #10 03-06-2004, 11:09 PM

OK... figured out what my problem is... two bad fuel injectors! I checked spark at all plugs and my FPR, which had dirt in it, but was otherwise OK. I then put a broom handle on each of the fuel injectors, and the 6 and 8 FI's were quiet as church-mice... bingo! I could not find anyone who stocked them locally, so had to special order them from Parts America.com...$82 each <ouch>. I think my problem is solved, and I got new plugs wires and acleaned out FPR as a bonus. Iwillpost a follow up when I get the new ones in. Anybody have any good tips on putting in the new ones?

Thank to all for the good advice...

JC

jjdewd · #11 03-07-2004, 02:00 PM

My car had been running great since new Delco plugs and wires. Just lately when I get up too speed(40mph) and level off if I gently give it some gas it chugs and twice in the last couple weeks even backfired thru the intake. Not loud ...just a pop.

If I give it quick gas it just goes but feels like its surging a bit.

This sound like and FPR problem?

Think I'm gonna replace it. Can someone tell me exactly where it is?

Thanks

jacoats · #12 03-07-2004, 05:02 PM

Quote:

Originally Posted by jjdewd

My car had been running great since new Delco plugs and wires. Just lately when I get up too speed(40mph) and level off if I gently give it some gas it chugs and twice in the last couple weeks even backfired thru the intake. Not loud ...just a pop.

If I give it quick gas it just goes but feels like its surging a bit.

This sound like and FPR problem?

Think I'm gonna replace it. Can someone tell me exactly where it is?

Thanks

Well.. I am no expert but I found mine, removed and cleaned the screen beneath it, as it was loaded with dirt. On my 96 was just above the number 7 fuel injector (last one on the right in the rear bank as you look at it from from the front). There is a horseshoe-shaped clip on it that comes off easily, and it comes right apart. There is a vaccum line on top, and there was a good tip earlier in the thread about pulling off the vac line and see fuel is getting into it. If it is, it's shot. If not, (as in my case), I just cleaned it all up and reassembed it. Good Luck

JC

jjdewd · #13 03-09-2004, 12:36 AM

thanks jacoats!!

jjdewd · #14 03-15-2004, 08:58 PM

Quote:

Originally Posted by jjdewd

My car had been running great since new Delco plugs and wires. Just lately when I get up too speed(40mph) and level off if I gently give it some gas it chugs and twice in the last couple weeks even backfired thru the intake. Not loud ...just a pop.

If I give it quick gas it just goes but feels like its surging a bit.

This sound like and FPR problem?

Think I'm gonna replace it. Can someone tell me exactly where it is?

Thanks

Ok I've since pulled my FPR and was clean as new. I blew it out with canned air and reinstalled it.
Stupid me I was running mid. grade octane fuel. I put a fuel system cleaner in and a tank of 93 octane fuel.
Now it runs smooth as silk! Not to mention it flies!!

jacoats · #15 03-20-2004, 05:27 PM

Well, my problems are not over yet. I found another Fuel Injector that was not working and was about to replace that this am, but the car started and ran for only a second (several times), now will not start at all. It cranks, stumbles and backfires once as it quits. I had this same problem a few months ago, but I thought it was due to a frozen gas line. When I replaced the two injectors, I noticed that there was grit in the fuel, and also in the FPR. I replaced the fuel pump around X-mas and even though I was very careful, I noticed that there was some dirt that had fallen into the tank. There was no way for me to get it out, and the fuel pump had a filter on it (not to mention the one in the fuel line), so I let it go. Now I am afraid it is getting through up to the injectors. How is it making it through the fuel filter? It is less than a year old.

I had previously said that I thought my FPR was OK, but it was gritty and it looks sort of shot. I just ordered one from Carquest for $54.00. I see no fuel in the vaccum line attached to the top of it, but after reading much here, it seems like that could be the culprit. When the car did run this am, it barely ran, and as soon as I tried to give it some gas, it stalled. The exhaust also smells rich, though i do not see black smoke. So a couple of questions:

1) Could debris from the fuel tank make it through the various filters, all the way to the FI's, and can they be cleaned if plugged?

2) does the FPR sound like the culprit in the engine not running at all now?

Thanks much for the help!

JAC

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