;helpPlease help! Im lost again! I have an 81' that just came out of the shop because the check engine light would not shut down after the car was off. The mechanic said it had something to do with cross wiring when i installed a new radio. Problem- the car hesitates in every gear, similar to when you dont let the clutch out properly in first gear, but in ever gear. Ive already replaced the ecm once, do you think i blew it some how. Please help, this car has been nothing but a money pit for me!
81' Hesitation while in gear
- Thread starter cheftl13
- Start date
Cheftl,
first of all, is your Vette automatic?
And if so, are you saying that when the car shifts it feels like or as if it had a manual clutch being released? In other words, it is not a crisp shift, right?
If this is the case, then what most likely is causing the problem is the lock-up solenoid in the tranny. When it weakens, the solenoid cannot positively close the lock-up port, and the drive line acts as if there was a manual clutch. Pretty straight forward repair ( drop the tranny pan, and the solenoid is right there); however, often the very same solenoid is hard to find even through Chevy dealers. They have one which you will have to re-wire like the one that you take out off your tranny. The reason for this is that the one available is the one that locks-up the converter on the final gear (3rd or "D"). The L81's lock-up in 2nd and final gear. So keep the one you remove and make sure you take note which cable leg comes off which shifter pressure switch to get the right performance back in the tranny. Place a tag or piece of tape to identify each cable lead. And then simply add an identical leg as in the old solenoid to your new solenoid.
GerryLP:cool
LVMYVT76
Well-known member
Probably could not be as simple as low fluid level.
- Thread starter
- #4
its standard. think of it like this. You know when you release the clutch wrong without enough gas and the car starts to buck, it is doing that in every gear, but seams more like its not getting enough gas. But like i said, it was perfectly fine until i put the new radio in, i messed up a cluster on the board, that was repaired. and now its acting like this.
Have you thought of disconnecting the radio wire conctions to see if your theory is correct?
- Thread starter
- #6
Hib Halverson
Technical Writer for Internet & Print Media
Diagnosis via the Internet is pretty tough in a situation like this but I'm going to guess that the problem is not the ECM. The engine would likely not run at all of if the ECM was faulty.
It's possible that the radio installation messed up the engine controls but not likely. The most recent post about the radio being disconnected....you didn't say how the car runs with the radio disconnected.
It's possible that the radio installation messed up the engine controls but not likely. The most recent post about the radio being disconnected....you didn't say how the car runs with the radio disconnected.
- Thread starter
- #8
Coincidences do happen. :ugh
So, do the following things:
1) Remove air cleaner and look down the carb, and make sure that the plates are fully open by actuating the throttle lever. You may have to manually push on the choke plate open to see the throttle plates below it. They should be vertical or nearly so. Observe to see if there is a ring of dirt near the location where the throttle plates contact the venturi tunnel.
2) Clean carburetor by running engine and shooting carburetor cleaner down the throat of the carb. You'll only be able to do this on the primary side. When there is NO load on the engine, it it very hard to get the secondary valves to open (maybe unlikely to open??
). 3) Understand that if your idle system side of the carb is not adjusted correctly, when the engine reaches main system engine speeds (1200 - 1300 rpms), the engine will use-up the mixture from the idle system before it transfers to the main system, and this causes problems as well (typically a bog-down and lean condition). For example, if you have the wrong settings at idle or perhaps have a vacuum leak, or even timing is set way-off where it should be, this could cause the setting of curb idle to open the throttle plates too much in order to maintain that idle speed, so now the throttle plates have a gap between them and the venturi tunnel instead of contact with it. So, check your idle settings carefully to ensure that your base settings are not throwing everything else out of whack down the line.
If the steps won't fix up the problem, then do the following separate troubleshooting:
a) Hesitation during light acceleration:
- 1) Check for intake vacuum leaks (to include the hoses that connect to the intake in one way or another).
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- 2) Do you have some bad fuel in your tank? (don't laugh, it happens..:L)
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- 3) Check your exhaust-manifold heat control valve for sticking/inop.
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- 4) Cogged air bleeds / passages (you already sprayed carb cleaner down the throat and it didn't help in the initial steps above, remember?
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- 5) Wrong timing setting; Again, see the very first 3 steps.
- 1) Wrong setting or failure of your accelerator pump.
GerryLP:cool
By the way, in case you could be right about the radio issue (causing some electrical problem), did you run a fault code check on the computer to make sure that you didn't short something in it?
GerryLP:cool
GerryLP:cool
LVMYVT76
Well-known member
could it be that you cat is beginning to stop up?? any way to unhook it to see if that takes care of it??
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