Miss/sputter during hard accel

[BlackMetal]

Just wondering if you ever found a solution?

No not yet, it's been too damn cold here to even want to spend 5 minutes out in the garage.

I probably will be switching to a 3.5" MAF with translator, so that should take the OEM MAF out of the question. Ignition coils/module still makes the most sense to me, so I might change those eventually. I still have to check the grounds like 'onefastcar' is talking about. It also looks like I have 2 leaky injectors so maybe there's a chance that under hard boost the injectors aren't doing their part.

But as I said, can't really make any progress while it's 8 degrees outside. Screw Chicago. I'll give an update whenever I make some progress.

 

[rking]

Still have the same problem with mine !! New coil, new module, new plugs, checked main ground coming from battery to the engine, checked I believe 4 grounds near the pass rear head, 13.7 volts on scanmaster when driving. Never shows knock. Plugs looked pretty good when I removed them!!! I have no idea where to go next!!

I will take any opinions, PLEASE!!!

 

[rking]

Just to maybe give you another option. On my old 84, I once had a crank trigger start to go out. Odd, I know, I thought that they either worked or didnt, but mine would break up and sound just as our cars are right now. I am going to put a new crank trigger on today with a new O2. I will let you know if any improvements!

 

[rking]

Just wanted to let you know that I found my problem. The crank sensor was going out, starting rubbing the wheel. That was it. You might want to check it, easy to look at, easy to fix, also something that you might never consider. HTH

 

[Bird of Prey]

so, where is this crank sensor? i have similiar problems with my car...

matt

 

[Jerryl]

so, where is this crank sensor? i have similiar problems with my car...

matt

This is a HA config but the crank sensor is in the same location on the IC'd cars.
http://www.turbobuick.com/forums/at...753d1120969316-basic-hotair-info-sensors1.jpg

 

[GN138]

I have the same exact issues. Start the car, let it warm up, drive it a bit and about 1/2 way to work it starts sputtering. After the car cools down (6+ hours) it will do the same thing on the way home from work.

I replaced coil and ignition module, plugs and wires.

If I start my car and unplug the CAM SENSOR then the issue goes away.

 

[fuzzyGN]

Mine has been doing the same thing. We have checked EVERYTHING that made sense. All ignition components, fuel pressure and volume, translator in place of stock MAF, all wiring, etc. etc. The only thing left is stuff that doesn't make sense; the cam sensor. I am charging my battery now but it HAS to be it, I have replaced everything else. For the guy with the Dutt neck, make sure to thouroughly check the bump hose at the transition point as they will crack. Hopefully this weekend I will get a chance to replace the cam sensor and give it a test run.

 

[Bird of Prey]

erik, please let us know if it was the cam sensor!!!


matt

 

[Blazer406]

Have you checked the battery cable going to the starter.... under the pass side header? Mine was shorting out (due to the engine torquing over) during hard acceleration sometimes... and when it shorted... it was killing the power to the ECM... and it would stumble.... then it would unshort almost instantly... and pick right back up... like 1/4 of a second later. I like to have never figured that out.

HTH

 

[Bird of Prey]

ok guys, i'm so happy i can't tell! I wanna hug my car all night now...

I just changed the spark plug wires and the stutters are away! So awesome! i'm happy....

good luck for your problem-solving!

matt

 

[BlackMetal]

Some of our supporting vendors are having great deals on ign modules and coils right now...but 20 other possibilities have been mentioned in this thread and I'm worried it won't be the solution.

ASAP I'll be doing 009 injectors, new MAF, alky kit, and a new TT chip to match it all, and maybe I'll get lucky and it'll not happen after that.

 

[Evans Ward]

Before you upgrade with all those mods mentioned, you might consider finding the problem and/or changing only one thing at a time. That logic will help you troubleshoot and diagnose much easier. Take up whoever said you could borrow some of their spare parts. I'm in agreement that it sounds like possible MAF or ignition module difficulties. Not throwing any codes??

 

[TurboBuRick]

Some of our supporting vendors are having great deals on ign modules and coils right now...but 20 other possibilities have been mentioned in this thread and I'm worried it won't be the solution.

ASAP I'll be doing 009 injectors, new MAF, alky kit, and a new TT chip to match it all, and maybe I'll get lucky and it'll not happen after that.

Scottie, we need to find the problem first, before the mods. Call me and we'll hook up.

 

[Blazer406]

Some of our supporting vendors are having great deals on ign modules and coils right now...but 20 other possibilities have been mentioned in this thread and I'm worried it won't be the solution.

ASAP I'll be doing 009 injectors, new MAF, alky kit, and a new TT chip to match it all, and maybe I'll get lucky and it'll not happen after that.

Have you had a chance to check this battery cable I mentioned? The only way I found it was with a datalog showing the battery voltage dropping very sharply all of a sudden while under hard acceleration.... this would cause the momentary stumble.... and then it would unshort itself... and pick right back up like 1/20th of a second later..... I would only get 2-3 frames (in DirectScan) where the voltage had dropped out.

 

[BlackMetal]

I haven't had too much time to check out everyone's suggestions. Busy with work lately, and on my days off I'm either busy or it ends up being 5 degrees outside and I can't work on the car. Hopefully we're seeing the last of winter and I'll be able to spend more time in the garage.

No, I wasn't implying that I would slap on all those mods at once and pray for the best, just mean that if I can't figure it out, at the very least I'm already planning to change the MAF and get rid of my leaking injectors, so if nothing else fixed it before then, maybe I'd get lucky.

I did look at the battery cable going to the starter and couldn't see anywhere that it would be shorting out but I guess I could try driving the car and watch for a voltage drop.

Rick I know you'd be happy to lend me a hand, I'd just have to find the time to make the drive out there (and again, catch a break with the weather).

 

[Blazer406]

I did look at the battery cable going to the starter and couldn't see anywhere that it would be shorting out but I guess I could try driving the car and watch for a voltage drop.

You would likely only see it on a direct scan log..... the whole event was shorter than 1/4 of a second. I would only get 2-3 frames maybe on DS.

HTH

 

[TurboBuRick]

Rick I know you'd be happy to lend me a hand, I'd just have to find the time to make the drive out there (and again, catch a break with the weather).

Sounds good Scott, hopefully we get some warmer weather soon. I actually took mine out last night for a little cruise. I jones to drive that car. Just got my new fullthrottle boost solonoid hooked up and working. The Maf-T-pro is a really a neat tool. I can adjust fuel, timing and boost now right from the cockpit.
You have my number, give me a call or shoot a PM when your ready.
We'll talk to you soon.

 

[jsta6]

 

[GNRick]

My OTC 4000 found the cause of my sputter. TPS sensor was bad. I could set it at .4 volts at idle and over 4 volts at WOT with key on, so I never suspected it was bad. During the run it went from .4 volts to 1 volt to 2 volts to .9 volts to 3 volts. The new TPS sensor fixed it.