BADASS of New England
Would you like to react to this message? Create an account in a few clicks or log in to continue.
BADASS of New England

An automobile club for the enthusiast who enjoys the last of the big GM cars. The rear wheel drive B and D bodys. Chevrolet Impala SS, Caprice, 9C1, Buick Roadmaster, Oldsmobile Custom Cruiser, Cadillac Fleetwood
 
HomeHome  Latest imagesLatest images  RegisterRegister  Log in  
Log in
Username:
Password:
Log in automatically: 
:: I forgot my password
Who is online?
In total there are 4 users online :: 0 Registered, 0 Hidden and 4 Guests

None

Most users ever online was 182 on Thu May 27, 2021 9:57 pm
Latest topics
» Wheel and Tire Bundles
Please help me diagnose a running condition problem. EmptyWed Oct 19, 2022 1:27 pm by scot

» Loss of a friend
Please help me diagnose a running condition problem. EmptyTue Oct 18, 2022 8:58 pm by silverfox103

» 2021 Fourteenth Annual B & D Roundup!! Mark your calendar! Saturday October 16th
Please help me diagnose a running condition problem. EmptyTue Sep 28, 2021 11:01 pm by silverfox103

» WTB - caprice parts
Please help me diagnose a running condition problem. EmptyFri Sep 24, 2021 9:53 am by ElKy

» 2021 Roundup Sign Up Sheet
Please help me diagnose a running condition problem. EmptySun Sep 19, 2021 6:22 pm by black blur 96

» Another Vehicle Thread
Please help me diagnose a running condition problem. EmptySun Jun 20, 2021 11:37 am by scot

» Wheel and Tire Recommendation
Please help me diagnose a running condition problem. EmptyFri Jun 11, 2021 10:41 am by scot

» 275/60-15 Nitto 555 Extreme
Please help me diagnose a running condition problem. EmptyWed Jun 09, 2021 9:41 pm by Chris Klein

» Allagash canoe trips 2021
Please help me diagnose a running condition problem. EmptyWed Jun 02, 2021 9:02 pm by Chris Klein

Search
 
 

Display results as :
 
Rechercher Advanced Search
March 2024
MonTueWedThuFriSatSun
    123
45678910
11121314151617
18192021222324
25262728293031
CalendarCalendar

 

 Please help me diagnose a running condition problem.

Go down 
3 posters
AuthorMessage
toomanytoyz
Club President
toomanytoyz


Posts : 6876
Join date : 2009-01-20
Age : 47
Location : East Hampstead, NH USA

Please help me diagnose a running condition problem. Empty
PostSubject: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptySun Aug 09, 2009 4:33 pm

95 Impala SS. GM846 cam. Ported aluminum heads. 1.6 roller rockers. F-body MAF, IIRC (or is it vette?). T56. Programmed by Scott.

Anyways, was running great until I took it to the track in May. It popped at the line on one run and then was having a roaming misfire, so I figured it was the cheap eBay chinese opti. I drove it home and it seemed to drive ok, but I was taking it very easy. I parked it when I got home from the track and went to move it into the garage about a month ago and the battery was dead. Which is curious because the battery was only a year old and had never been drained before. I took it to Autozone to swap and it was at less than 3V and would not bounce back (I had tried to charge it, too). So I replaced the battery. The following weekend, I went to bring it into the garage and the battery as dead again! So I jumped it and it seemed to be running very rough and stumbly. But I only just backed it down the driveway and then pulled it into the garage.

I finally got around to swapping the opti for a known good one today. It wasn't the problem. Now, it won't rev at all. It stumbles and pops up through the intake. It idles great. I am certain the plug wires made it back to the right spots as I marked them before I took the old opti out. Sometimes above 3500rpm it'll clear up and rev great til about 5500 where I've let off. Then blip it again and it stumbles and pops through the intake. Bad. So I tried the coil wire. No luck. I swapped in a brandy new coil. No luck. It was running so poorly that I did not take it for a ride. Runs the same with the MAF unplugged. I decided to walk away before I took my temper out on it.

What do you think it could be? I plan to run it tonight in the dark to look for obvious arcing.

Fuel pump? I dunno... Idles ok and seems to rev fine once it clears itself up.

PCM?

ICM?

Bad plug wire?

Please brainstorm with me.

TIA!
Back to top Go down
http://impalass.uniquekind.net/
Guest
Guest




Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptySun Aug 09, 2009 4:42 pm

Check the condition of the wires going to the coil, and opti. Could be a failed connector. I find most battery drain issues wind up being an open circuit in a bad relay. I would look around at the wire harness. Maybe a wire got burned and is now touching what burned it and draining the battery.
Back to top Go down
toomanytoyz
Club President
toomanytoyz


Posts : 6876
Join date : 2009-01-20
Age : 47
Location : East Hampstead, NH USA

Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptyMon Aug 10, 2009 9:00 am

IMPALADAKID wrote:
Check the condition of the wires going to the coil, and opti. Could be a failed connector. I find most battery drain issues wind up being an open circuit in a bad relay. I would look around at the wire harness. Maybe a wire got burned and is now touching what burned it and draining the battery.

Yeah, I checked all the wiring yesterday. Nothing looks burnt. I only mentioned the battery because it seemed too coincidental that the drain showed up at the same time. But, the battery held a charge from when I brought the car in the garage a couple weeks ago til yesterday. I put it on the charger just to top it off.

The only wire I can think of that may be melted is the #6 plug wire at the plug. The pos budget headers sit right on the boot. But I have it wrapped with all kinds of heat insulation. Checking that one would require removing that header, and I'm not all that excited about doing that. Wink It's a last resort as far as I'm concerned! Wink

On a related note... Anyone know a shorty plug that will cross reference to a TR55?

Any other suggestions for the running condition problem? I may try a known good ICM today if I can get some time to work on it.
Back to top Go down
http://impalass.uniquekind.net/
Guest
Guest




Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptyMon Aug 10, 2009 10:13 am

I would try the ICM, or PCM. Didn't I leave a ICM behind from Riches car? I think it worked. If not, I have two more if you don't. Your best bet is to get with someone with a laptop. I know you have one, but you know what I mean.

BTW. At the track, what exactly happend? You said it poped then started running bad. Can you elaberate?

Accel is the only company I know of that makes a short plug for header use.
Back to top Go down
mean ss

mean ss


Posts : 648
Join date : 2009-02-25
Age : 66
Location : Nashua NH.

Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptyMon Aug 10, 2009 11:08 am

I bet money it's the PCM






Laughing


Last edited by mean ss on Mon Aug 10, 2009 9:34 pm; edited 1 time in total
Back to top Go down
toomanytoyz
Club President
toomanytoyz


Posts : 6876
Join date : 2009-01-20
Age : 47
Location : East Hampstead, NH USA

Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptyMon Aug 10, 2009 1:35 pm

IMPALADAKID wrote:
I would try the ICM, or PCM. Didn't I leave a ICM behind from Riches car? I think it worked. If not, I have two more if you don't. Your best bet is to get with someone with a laptop. I know you have one, but you know what I mean.

BTW. At the track, what exactly happend? You said it poped then started running bad. Can you elaberate?

Accel is the only company I know of that makes a short plug for header use.

I have that ICM still, and at least one other. I'll try it today if I can get a chance to work on the car. I'm with the baby today and I think Momma is going to have to work late. And you're right. I really need to get some software on my lappy! Anyone have a copy of datamaster or something? Very Happy

Well, for the past couple years, the car had an occasional stumble going from idle to WOT. Didn't happen all the time, and when it did, it was for like a 1/2 second and then it was fine. I replaced all sensors underhood, including MAP, knock sensors, both CTS's, o2's, and a couple different MAF's. Never fixt it. Now up at NED, I was ripping off those mid 13's and then the first round of eliminations, it popped through the intake at the line when I got on it, fell on it's face and then sputtered it's way to a win light and a high 15. I took it into the pits, found that #1 was not firing. We swapped the plug out, even though the one in there looked fine, and the miss went away. Went up for round two of the elims and the same thing happened. Came back into the pits and #3 was now not firing. I decided to bow out of the races and just limp it home at that point. And it drove home without a hiccup. Tho I never did get on it at all.

And now, here we are. Smile


mean ss wrote:
what are the volts at the battery eng running ? are those new lights causing a draw?

if you need to try any of my parts I'll be home

It's at 13.9 or so, IIRC. I didn't check that yesterday. New locally rebuilt alternator last year and new battery cables, too.

The new lights are on the Marshmallow. Smile
Back to top Go down
http://impalass.uniquekind.net/
bammax

bammax


Posts : 2301
Join date : 2009-02-22
Age : 42
Location : Mansfield, Ma

Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptyMon Aug 10, 2009 1:49 pm

Would it be possible that the signals to the injectors are screwy? Maybe there's a short in the circuit that's making the injectors fire out of sequence under full load, like when poorly insulated plug wires cause a crossfire. The odds are almost nill but it would explain your issue and these engine harnesses have been known to do funny things once they've been moved around a bit.

I'd backprobe a couple when the misfire comes back and rule it out. Remember it can only be spark or fuel and your ruling out alot of spark issues already.
Back to top Go down
Guest
Guest




Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptyMon Aug 10, 2009 1:59 pm

I would look at injectors and injector pig tails as Brad mentioned. They sell pulse lights that plug in between the pig tail and the injector. This will tell you if they are working corectly voltage wise.
Back to top Go down
toomanytoyz
Club President
toomanytoyz


Posts : 6876
Join date : 2009-01-20
Age : 47
Location : East Hampstead, NH USA

Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptyMon Aug 10, 2009 8:35 pm

Well Bobby (mean ss) came over with a fuel pressure gauge and vacuum gauge tonight for us to check things out. 43.5 lbs of pressure @ idle. Went up with throttle. Held 41 lbs when off. Vacuum was good, low because of the cam, but good. Did what it was supposed to do with the throttle.

Swapped opti harness. No change. Swapped ICM no change. For sh!ts and giggles, we swapped PCM's with one with a stock tune, and it ran fine. Stumble and backfiring went away! WOOT!!!! So now I gotta see if I have a copy of my tune and will try dumping it in tomorrow.

So hopefully that was it! A bad PCM. Who'da thunk it?

Thanks for the help, Bobby! And to all that offered advice!
Back to top Go down
http://impalass.uniquekind.net/
Guest
Guest




Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. EmptyMon Aug 10, 2009 8:46 pm

Maybe you have a bad PCM. Razz
Back to top Go down
Sponsored content





Please help me diagnose a running condition problem. Empty
PostSubject: Re: Please help me diagnose a running condition problem.   Please help me diagnose a running condition problem. Empty

Back to top Go down
 
Please help me diagnose a running condition problem.
Back to top 
Page 1 of 1
 Similar topics
-
» Need diagnose help: '94 Caprice w/LT1 ignition prob
» Looking for 1 SS wheel.. any condition...anybody?
» Wtb Stock 17" impala SS wheels any condition.
» My car just started fing up REAL bad.
» an odd ABS problem

Permissions in this forum:You cannot reply to topics in this forum
BADASS of New England :: 91-96 B & D-body tech :: Problems / Maintenance-
Jump to: