Bucking, jerking and clunking @ low RPM from a dead stop......

[99gst_racer]

This is starting to scare me. I just pulled my car out of storage. It's been up on jackstands for the past 4 months. Here's my problem. As soon as I let off the clutch (in 1st gear) from a dead stop, the car jerks around REALLY bad and there is a horrible clunking sound. It does it a little bit in 2nd at low RPM's too. Mostly in 1st when taking off from a stop though. As soon as I let off the clutch and give it a little gas, it feels like I hit fuel cut 3 or 4 times and then the car goes. I know this isnt a fuel cut problem, I'm just trying to give you guys an idea of the feeling. The clunking sound sounds like a car driving down the road with only one loose lugnut holding each wheel on. This has nothing to do with boost, it all happens below the 3000 RPM mark. Is there any DSM expert out there that might be able to give me some help, advice, or pointers...... ????

 

[fertez_turbo]

I'd check the tranny fluid.

 

[leet]

Is it a mechanical clunk, or a clunk from the car trying to stall?

If it's not mechanical, try checking your ignition system.

 

[99gst_racer]

Originally posted by fertez_turbo
I'd check the tranny fluid.

I just changed the tranny fluid out. Now it's running BG Syncroshift.

Originally posted by leet
Is it a mechanical clunk, or a clunk from the car trying to stall?

If it's not mechanical, try checking your ignition system.

I do believe it's mechanical, and I dotn think it has anything to do with the motor.... BUT, I am going to check my ignition now that you remind me..... Other than plugs and wires, what should I check?? And where can I get the CAPS on my ECU replaced?? ( I think they're bad) Can they do it at DSMlink?? Thanks for the replys

-Paul-

 

[dsmturboawd]

i have the exact same problem. most the time the car runs great. every once in a while, when the car is under any load at all, it will studder and hesitate really bad. when i say load, im saying any kind; like if i were to start going from a stop without even comming close to building boost, the car would hesitate.

wires and plugs didnt help. no ic leaks. i was thinking coil pack, but those either work or they dont from what ive read.

ill go swap out my mas for one thats in the basement. other than that, any ideas?

 

[dsmturboawd]

could be fuel filter, i put some fuel cleaner in today and it helped a bit from what i can tell so far.

ill be replacing my power transistor and coilpacks tommorrow for shits and giggles.

 

[99gst_racer]

Originally posted by dsmturboawd
i have the exact same problem. most the time the car runs great. every once in a while, when the car is under any load at all, it will studder and hesitate really bad. other than that, any ideas?

Many times when people have problems with hesitation under load have leaking CAPS on the ECU. Get 'em checked out.



My problem is total different. I dont have hesitation. When I let off the clutch, it feels like I'm going over 12 speed bumps at 30 mph. Thats not hesitation. And I'm definately not under any load.

 

[racer]

shit man I have the same shit,feels like im going trough speed bumps and it does it only under 2500-3000 rpms even that Im N/A.We have check every ####in part.Plugs and wires,fuelfilter has like 4k only,fuel preasure is steady at 44psi at idle and it rises perfect when open trotle,timing good(with timing gun),trotle position censor works perfect,
steper motor is new (4-5k miles on it),MAF good(they dont go bad),ECU and all caps on it good.It started doing this from like 4 moths ago.Im starting to think that it is some kind of mechanical problem.My mechanic couldn't find anything.I dont even think that there are many ppl that could have any ideas.Hope someone comes up with someting soon.

 

[fireredGST]

Change your spark plugs , I have the same problem , and many of the guys on the board have told me this should do the trick.

 

[racer]

but they are good.We check them very carefully and all good.Aint that.I have aftermarket 8mm wires.They are expencive.I dont wana just buy new one if im not sure that it is the problem.The are very good.Look like brand new.Im sure they'll never get bad.So i gess I should just put new plugs only but i doubt this will fix the problem.

 

[99gst_racer]

Originally posted by fireredGST
Change your spark plugs , I have the same problem , and many of the guys on the board have told me this should do the trick.

Yeah I am going to give it a try. I ordered some new plugs through Slow Boy and they came today, but nobody was here to sign for them, so hopefully, I'll get them tomorrow. I'll let you guys know if it fixes the problem.......

 

[fireredGST]

Originally posted by racer
but they are good.We check them very carefully and all good.Aint that.I have aftermarket 8mm wires.They are expencive.I dont wana just buy new one if im not sure that it is the problem.The are very good.Look like brand new.Im sure they'll never get bad.So i gess I should just put new plugs only but i doubt this will fix the problem.

Actually you have a N/T , so I don't really know. I was referring to the guy who said his car bucked and had a GST.


Maybe your N/T has a clogged fuel injector ? That happened to me a little while back when I had my ford probe.

It was bucking horrbily, and I was losing alot of power, turns out 2 of my injectors were clogged.

 

[phastalon]

i had the exact problem, and trust me, it will get worse and leave you stranded in a conoco parking lot on your way to work.

there were 2 parts that i had to replace and if i mess up the names, please don't bash me...ignitor coil and ignition switch i believe.

anyways, i was stalling in the lower rpms and i could press the gas all the way to the floor and just stutter until it finally caught. then it got to the point where i could put the gas all the way to the floor and it wouldn't go above 1500rpm

 

[99gst_racer]

My motor seems to be running just fine. It doesnt seem to be stuttering at all. It feels like my tranny is trying to jerk itself off the motor.... It could be something totally different, but I am clueless at this point. I'll try plugs and go from there......

 

[dsmturboawd]

Originally posted by 99gst_racer
Many times when people have problems with hesitation under load have leaking CAPS on the ECU. Get 'em checked out.

never heard of leaky caps in a 2g.

 

[phastalon]

Originally posted by 99gst_racer
My motor seems to be running just fine. It doesnt seem to be stuttering at all. It feels like my tranny is trying to jerk itself off the motor.... It could be something totally different, but I am clueless at this point. I'll try plugs and go from there......

does it do it only when you are moving or does it do it while rev as well?

 

[99gst_racer]

Originally posted by phastalon
does it do it only when you are moving or does it do it while rev as well?

Nope, only when the car starts moving. Thats what leads me to believe there is a clutch/tranny/axle problem...... Got any ideas?

 

[racer]

actualy i get this shit when i first start the car and leave it at idle.It'll bog like every 10 sec or so until it worms up good.Also when moving only under 3000 rpms,feels like i go trough many speedbumps.The other thing is that it doesnt do it all the time.Some times it will not do it for like 2-3 weeks.I duno wtf is that shit but I can not stand it anymore.I'll make this bich my pizza car and will never buy me dsm again.Rx-7 in ma mind or Suzuki GSX-R ^^ (15 grand siting in ma bank)

 

[phastalon]

Originally posted by 99gst_racer
Nope, only when the car starts moving. Thats what leads me to believe there is a clutch/tranny/axle problem...... Got any ideas?

hmmmm...... most of the times with a cracked axle or broken axle there will be a thump instead of a hesitation/jerking. most tranny problems that i know about will either cause grinding or popping out of gear instead of a hesitation/jerking as well. your problem may be a clutch problem but usually you would have slippage instead of hesitation, and the two feel totally different of course.

i'll have to think about it and get back with you, i'm going to look at the manual for now and see what i can find

 

[racer]

do not forget me,I still want good working pizza car. :laugh:

 

[99gst_racer]

Originally posted by phastalon
hmmmm...... most of the times with a cracked axle or broken axle there will be a thump instead of a hesitation/jerking. most tranny problems that i know about will either cause grinding or popping out of gear instead of a hesitation/jerking as well. your problem may be a clutch problem but usually you would have slippage instead of hesitation, and the two feel totally different of course.

i'll have to think about it and get back with you, i'm going to look at the manual for now and see what i can find

What would be wrong with the tranny if it were grinding or popping out of gear?? Just curious...... Also, where the axle goes into the tranny, that's called the CV joint, right?

 

[Zenja]

I'm having the same problem. When I give it gas (especially fairly lightly) at low RPM in a low gear the car will lurch and heave, first at like 2 per second then getting faster and weaker as I accelerate. I'm thinking it might be something with fuel delivery or ignition. Hell, it could be a leak of some kind or something blocking air too. I hate these kind of problems.. there are always so many things to check. Not only that, but there are usually other more important problems to get to first

 

[mark_l]

I've been having the same problem. I kept chasing the problem. Injector upgrade, switched to 2g mas, fuel pump, electronic fuel gauge (to watch fuel pressure in car), went with individual coils, #6 fuel line, and high flow fuel filter. I tried playing with my afc to get rid of it also. After all of this, nothing. Re-chipped EPROM and replaced the caps in a different ECU, same thing. Finally I had the head rebuilt with 1mm oversized valves, bronze guides, dual valve springs, and new lifters. It fixed the problem. The machine shop said that my factory valve guides on the exhaust side were shot. This caused the #4 cylinder to not seal during combustion. When this problem was happening my EGT gauge would rise very fast. It did not happen all the time though. When this would happen I could rev the car up and for say set the valves under no load. Hope this helps.

 

[tboostndsm]

have any of you guys tried doing leak tests on the s pipe coming from the compressor housing to the sidemount intercooler.Mine lookes like it has been rubbing up against something but I havent tested it yet.My car hesitates only under boost in between 7-16psi.It feels like im hitting fuel cut like 5 times at once,but my a/f monitor goes two lights towards lean when it happens.My boost gauge will flutter slightly when it happens also.The mods i have are 3'' dejon intake,1 gen bov,s-afc,uicp,3'' downpipe back exhaust with 2.5'' apexi muffler(no cat),boost/vac,oil press.,and a/f ratio guages.CAN ANYONE HELP ME?

 

[mazdamx6pwr.com]

I'm not sure if this is relevant to the DSM community. But, here goes. The 2001+ Mazda Miata's had a problem with clutch shudder which was caused by defective friction material in the clutch disk not mating right with the pressure plate and flywheel. I have also heard Toyota and Honda have both had this problem with newer models also. Where you have a newer DSM I figured I'd mention it.