Well, my Iroc lives! It has been in storage for 2 1/2 years, but after fluid changes she cranked up...although it stalled a couple times. I did not change the fuel. Here is the problem, under light acceleration (less than 1/4 throttle, between 1-2.5 RPMs) the car surges/bucks and when I come to a stop it feels like it will stall and sometimes does. The surging/bucking doesn't happen as often when the car has been driven for a while. Lastly, the surge/buck feels like: when you are driving stick and you decelerate but forget to downshift...but the surge is more forceful...kind of like a beginner on manual learning to get out of first. Any thoughts? The car is a 1987 305 TPI, 5sp with March pulleys and Hypertech chip. I'm pulling the chip and 160 thermostat this week. Thanks!

 

Sounds like the torque converter clutch isn't disengaging. Did you change the transmission fluid & filter?

Less likely, the engine is complaining. Full tank of fresh gas and a new fuel filter would seem to be in order.

 

No, I didn't touch the tranny. My mechanic is going to give it a look on Friday and I'll have him check the torque converter clutch. New fuel and filter will also be added...didn't want to tackle that in my garage. Thanks!

 

Agreed about the torque converter. Although the only thing is the converter will only stay locked in 2nd gear and up. Can't lock in first.

 

Wait a minute, I missed the part about "5sp".

You don't have a torque converter. Are you saying it does this as you come to a stop with the clutch depressed?

Perhaps you have a clutch hydraulics issue.

 

Ooops, how did I miss that one...guess you can tell I'm pretty much a novice. Yep, the car is a 5sp. The clutch is not depressed when it happens -- the car is in gear and under light acceleration. Paying closer attention today, it seems like the RPMs are dropping and then surging. Car undergoes a big time jerking feeling...like a begginner on stick is driving and having trouble getting out of first. Any thoughts? Thanks!

 

Do a complete tune-up: plugs, wires, cap, rotor, fuel filter, air cleaner.

Let us know.

 

Will do!

 

Maybe I can speed this up!

I have the same exact problem and I just did complete tune up except the fuel filter.
Just like 87rediroc, if I try to hold a constant speed in 1st through 3rd, I have to accelerate just to stop it from bucking/surging. It happens a little in 4th but it’s not that noticeable.
I'll also throw this in, let us know if this happens to you too 87rediroc.

If I give it a little gas and move, let's say less than a car length like being stuck in traffic or parallel parking, the car wants to stall and very often does. Giving it gas doesn’t help much either. And if it does stall, it takes about seven or eight crank revolutions to start her up again. If I shut the engine off normally for a few minutes, she starts with no problem. Only when she stalls does it worry me a little when trying to start up again.

I have a 305 TPI and 5-speed combo too and I’m going to check my fuel pressure tomorrow.

Thanks.

Scott

 

Thanks Scottlb9. Our problems sound very similar...and I must applaud your engine/drivtrain combo. The only difference appears to be that increasing gas did not make it feel like it would stall, my car felt like it would stall when I was decelerating and the car was out of gear. I replaced the plugs and fuel filter and it does not really do it anymore. I think it might have been a product of some shady gas and the fact that the car sat for 2 1/2 years. It is my daily driver for the summer, so I will see how it goes this week. However, it did not surge last week. Please let me know how your fuel pressure reads, I'll be installing a fuel pressure regulator in the coming weeks.

 

Two words...Fuel Filter.

87rediroc and everybody else who searches,

I changed the fuel filter today just to rule it out and quite possibly, prepare for a fuel pump replacement. No need for the fuel pump because the filter was all I needed.

No more surging, no more stalling and, a comfort to cruise in any gear at any speed.

87rediroc, I haven't check my fuel pressure yet but I'll PM you when I do.

Scott

 

Never mind that last post! The filter change made it only run nice for a bit because she's now up to her old tricks again.

Nevermind moving, if I hold it around 2000 RPM's and then take my foot off the gas, the RPM's fluxuate between 1000 and 400 and sometimes stalls!

Back to the drawing board.

Can anybody in here point me in the right direction?

Thanks.

Scott

 

You guys really have to get your respective fuel pressures posted up. And '87, do like the Kid says and change your fuela and filter.

 

I had this same problem with my 86 305 with 5-speed. The car had set for 4 years. I changed the air filter, oil & filter, and put a new battery in it, and it started right up. I had basically no gas in it, so I didn't empty the tank, just filled it up. And it bucked when cold until revs were >2000. Last weekend I changed the fuel filter (and put in a nice 170 degree thermostat ), and now it runs fine. If you change the filter but haven't run a couple tanks of clean gas through it first, you're just going to crap the filter up again. I'd go spend another $3 and try again.

 

YEP --- Try another fuel filter!!!

If it works for a short time again then your problem is cr*p in the tank that keeps plugging up the filters.