67 Camaro

ok ... put a tech 1 on the 2.8 Camaro and it said MAF, o2, and timing. I replaced the o2 sensor and have a MAF coming from someone. Just yesterday this has gotten bad though..... the car would be going fine in gear and all the sudden would completly lose power. I put it in neutral and press the gas.... motor does not rev but tries and backfires a bunch. I end up having to turn the car off and restart it. Runs fine as long as I wait a good few seconds after turning it off. If I unplug the MAF sensor it does the same thing.. it idles, but has no power and wont rev.

Ive had the suggestion of wiped lobe from a bad lifter maybe... bad distributor... and/or timing way off. Just seeing if anyone might know for sure or had seen something similar happen


-Bud

...didnt know if it was V6 tech or 3rd gen tech.. but stuck it here b/c I asked a guy in the club about it and he was saying his GTA did something similar when his maf sensor was going out... so... heh

87IROC-Zowner

When the MAF went out on my '85 305 TPI Z-28, it never threw a code until after about a week of testing/troubleshooting the problem. I checked everything from fuel pressure to the oil level in my rear-end (lol). After it finally threw a code, I swapped the MAF from my '87 and problem went away. Reman MAF was about $160 from local parts house.

I had my '85 at college and had it on a Motor-Vac cleaning the fuel system when all of a sudden it died. Stumbled, backfired, missed and carried on all the way home, and I didn't think I was going to make it at a few points. It ran perfect, then just like flipping off a switch, it was screwed up.

RedIrocZ-28

Buddy Ray, I'm gonna have to go with fuel pump here.

My car's fuel pump died October of 2001. WHEN I could get the car started, it would stumble and spit and sputter no matter how far down I pushed the gas pedal. Fuel pumps can act very strange. Get a Fuel pressure guage and get it on the fuel rail to see what you're at.

Good luck man-g.

67 Camaro

Brad, ... forgot the mention that I did replace the fuel filter at the same time I did the O2 sensor. Problem still occurs. It was real bad the other day.. but its only done it once today. I'd like to drive the 2.8 to the Atlanta Gathering.. .but gotta fix 100% of the problems and be confident in the car to drive that car...... hopefully.

-Bud

Drkhrse89

Not the filter the fuel pump itself. I have to agree on this one. I think that it just took a dump on you. I had almost the same problem as you mentioned with my IROC.

87IROC-Zowner

A buddy of mine has a '89 IROC 305 TPI and just today he called me up all upset cuz it died on him at a stoplight in the middle of town. It would start up fine, but just as soon as he touched the throttle, it would die. He was major pissed off and lucky for him he called me first before a tow truck. I told him to unplug his MAF sensor and drive it home. Sure enough, as soon as he unplugged it, I heard him fire it up and drive off down the road (spinning every gear ) but at least it did get him home. The one thing that lead me to conclude it was his MAF was when he was trying to crank the engine, I could hear it backfiring through the intake over the phone. I knew right away the MAF had gone bad. My '85 did the EXACT same thing on me, except I spent 2 weeks trying to troubleshoot the problem. My Buddies' IROC had a new fuel pump installed (by me of course) so I knew it couldn't be that.

I know you said that it still acted up while having the MAF unplugged, but I figured I'd share my experiences with MAF's.

67 Camaro

well I checked the fuel pressure tonight and it was ~37 running. Timing was jumping from 12-14 idling ~1000rpm (sometimes it idles @2k.. sometimes normal @600 or so). I've also got a vaccum leak on one of the small hoses near the TB. Going to fix the vaccum leak tomorrow...

-Bud

EDIT: Oh yea... I unplugged the MAF tonght again and it acted fine. Revved and idled.. just real rich.

67 Camaro

Replaced the MAF sensor today... idles good and feels much smoother. Replaced the vaccum hose that was busted. But it still died on me once after I replaced it....