PDA

View Full Version : stalling/ code fun



TheDeuce
09-08-2010, 08:06 PM
Ok, this may be a little lengthy but I want to make sure I cover everything. For a little while now I would have this problem with my ‘85 6000 STE. After driving a while, or taking the car out an hour or so after a decent trip, when I would brake the revs go down as expected, but they would go down to about 250-500 rpm right at the point when I completely stop and it would seem like the car wanted to stall but it would sort of “catch” and get a slight surge to bump the RPMs up to 500-750. Then the check engine light would come on and give a code 34- MAF sensor. Not having the money at the time, I couldn’t replace it but I cleaned it with MAF sensor cleaner and it wouldn’t happen all the time, maybe once ever few months, always on a later trip when the car was warm, after being stuck in stop and go driving, etc, and after the car would run like crap, hesitating to accelerate after a light or whatever, then catching up, until I turned the car off.

Then a few weeks ago, while driving home from my new job, I was cruising at around 45 and the car just started surging, getting me up to 55 in a second and the engine light just flashed, not stay on. This happened once more. Then a few days later it started that while cruising along the revs just drop to zero , like the car says “I quit” and I have to furtively pump the gas to keep going. This was always on my way home from work in the afternoon after the car sat all day save for my going for a little drive at lunch time, which I do to get out of the building every day. Then last week, while stopping to turn in to the parking lot, it stalled and took a few tries to get it started again. That night while making a tight turn out of a parking lot after getting drive thru it stalled out, started after a few tries. The next day, Saturday, after going out on a second trip that day it did the “I quit” thing while driving and I stalled on the street, angering people. Again after a few tries and some pedal pumping it started again and I hurried home.

I decided to change the fuel filter since it’d been a little while since changing it before and the fuel pump is only 5 years old, and in that five years I didn’t travel that much, and it was the quickest and easiest thing to do. I use Lucas fuel treatment every so often as well. Did that as well as replaced a bit of gas line that looked like it was leaking. Noticed that the return line to the tank was kind of rusted and could use replacing sometime, but I didn’t have any more replacement line. Took it for a test run and everything seemed good, until it did the “catch” / sensor light thing. Code- 34. Monday I installed a new MAF sensor, reset the computer by pulling the negative. Everything seemed good on a long trip.

Then yesterday on the way home after stopping at the grocery store for about 5 or 10 minutes on my way home, it didn’t want to start. Took a few tries but it started. Then at a light, the “catch”/code 34. Then this morning I was going to work and it did the “I quit” thing, but I was able to get it going by pumping the pedal. This is the first time its done that on the first run of the day, the others were later in the day on a separate trip. Coming home was ok but it seemed to be running a little rough, but that might just be my paranoia and worry about stalling in rush hour.

What could this be? Fuel pressure problems? Computer issue? Vacuum issue? Heck, maybe it just needs to be tuned up. I’m lost and scared I’m going to stall and get hit and then be really screwed.

Century7667
09-08-2010, 09:41 PM
If I had only one guess, I'd say it's starving for fuel. I had a 2.5 once that somehow sucked carbon pellets from the carbon canister into the fuel bowl, and the pellets were intermittently plugging the jet in the carb. Sure sounds like fuel delivery to me.

Ken T.

Prospeeder
09-09-2010, 03:36 AM
This is why most 2.8 cars with the MAF systems were converted by the dealers to the MAP only system, had tons of problems like this. So what you need to do is go to the junkyard and find an old 84-87 2.8 Ciera/Centry 6000 with the same engine, but thats obviously been converted, Iv seen alot of them with the MAF still there but it has a sticker saying its been converted. Youll need the ECU, maybe just the PROM, possibly the map sensor, somebody here has probably done it could chime in.

dcjredline
09-09-2010, 10:46 AM
Good call Prospeeder. You can check fuel pressure just for fun that should be pretty inexpensive. Check your spark plugs, just pull them out and look to see they can tell you alot about your engine and how its running.

TheDeuce
09-09-2010, 11:33 PM
Ok, I'm starteing to lean toward a fuel issue. Today i went to and from work including going out at lunch time with no problems. Then my sister showed up about 15 minutes after I got home, so I wanted to swap cars in the drive way in case I went out later. Started it up and it seemed to be running a bit rough. I backed out and it really felt like it was going to stall but didn't. Pulled back in and right as I stopped it just died. I tried a few times to get it to restart and nothing. Tried it withot touching anything, tried it while pumping the gas, tried it with the pedal all the way down- nothing. After a bout 10-15 minutes I tried again, and it started but really sort of shaky. Reved it a few times and decided to give it a spin around the block just to get everything moving. Immediatly after turning the corner, died. I pushed it to the curb, nothing. Walked home and came back like 30 minutes later, nothing. Let it sit for an hour- success. Took it around the block, got home, turned it off and decided to try it- just cranking. Then I got an idea, i pulled the gas cap off. It took a few tries but it started. Just tried it now, about an hour and a half after last time- it started up. The temperature outside has also dropped a good 10-15 degrees. Could this just be a bad gas cap not venting correctly? I noticed a few months ago that the fuel pump doesn't exactly sund like it did before, so could it just be a failing gas pump? I feel like I'm so close yet so lost.

Also, I pulled a plug yesterday after posting the first post. It looked ok, but definatly worn. Gap was off from general wear and tear, but no fouling or anything. I was planning on getting a tune up anyway, and I was going to run this problem by my guy today, but they can't take my car until next week.

Prospeeder
09-10-2010, 03:06 AM
Exact symtoms of why GM converted all those cars from the MAF systems under a service campaign....

TheDeuce
09-11-2010, 06:03 PM
Well, after I stalled out and couldn't restart yesterday coming home from work {in the left hand turn lane, which angered a lot of people} I had the car towed to my shop. Dianosis- bad spark modulator and distributor rotor. Just picked it up. A full tune up comes later this week.

'84 6000
09-11-2010, 11:59 PM
Exact symtoms of why GM converted all those cars from the MAF systems under a service campaign....

When did they actually do that conversion as I had never heard of it until the last couple years?

For all its worth, I have ran my 2.8L in the Celeb with the Maf and swapped engine and trans into the '90 Cavalier with an '88 Ciera ECM(it has been flashed to map only by GM) and honestly, the gas mileage sucks in the Cavi vs. the Celeb. It lost about 10 mpg

Prospeeder
09-12-2010, 01:19 AM
they started converting them in the late 80's the last few 2.8's with Maf sensors were in 88, then 89+ went to the map style, thats when the campain started