87 chevette won't idle:

[Stewart G Griffin]

87 chevette:

Starts ok, but won't idle unless you keep the accelerator pressed about 1/4 of the way down.

Any suggestions?

Can i put a paper clip in ports B and A in the diagnostic connector?

How would you hook up a tach?   The distributor does not seem to have the coil in cap

[zieg85]

First thing I would check if it were me would be the operation of the EGR valve, second would be all the rubber lines for a broken/cracked hose.  Did this issue just surface?

[Stewart G Griffin]

No the issue has been there since i got it.  i am only now getting to it.   i will check all the hoses more carefully.  How do you check the egr valve?   But there shouldn't be egr at idle anyways?

[zieg85]

No the issue has been there since i got it.  i am only now getting to it.   i will check all the hoses more carefully.  How do you check the egr valve?   But there shouldn't be egr at idle anyways?

You are right but if it is slightly open due to carbon build up it won't idle.  The EGR's I have seen are open so you can fit a finger in it and pull it open

[Stewart G Griffin]

No the issue has been there since i got it.  i am only now getting to it.   i will check all the hoses more carefully.  How do you check the egr valve?   But there shouldn't be egr at idle anyways?

You are right but if it is slightly open due to carbon build up it won't idle.  The EGR's I have seen are open so you can fit a finger in it and pull it open

You were right, the service manual said to check egr valve after doing the diagnostic test thing and carb float level.

Anyways, i started it up and now it DOES idle and maybe even a little too high.   The electric choke does not seem to be working as i idled for at least 5 mins.  So it was stuck on hi-step.  Once i manually opened the choke plates the rpm dropped.  BTW the carb is i think a holley 5210 2bbl (1 primary and 1 secondary) and all chevettes had them 78 and up i think.

i'm not sure why it's ok now, but when i bought it it would not idle?   i didn't really do anything except look it over/work the throttle etc.   i bought it in the summertime and it is now 32 degrees and falling, so maybe the choke was too rich for summer and now since it's so cold the engine will run with the choke rich?

Since the time i bought it, it sat for a while and i did not rerun the engine until now.

[Stewart G Griffin]

Actually, i remembered that i fiddled with the "Stepped Speed Control" cannister;  this is sort of like an idle solenoid where if you turn on the A/C in will bump up the idle.

i applied vacuum to it to test it, as suggested by the service manual, and it sounded like maybe some dirt got disloged and all of a sudden started extending/retracting as it is designed to do.  So maybe this was it.  i don't know.

It this case, it is designed to bump the idle up for A/C, power steering if pressure exceeds a certain level and for manual transmissions if the engine exceeds a certain specified speed.

i don't know if all chevettes have this, but 87's do.


2) Would anyone know how to hook up a tach to an HEI WITHOUT the coil in the cap.  i can't see anywhere to plug the tach lead to the distributor cap.

[VileZambonie]

Negative side of the coil.

[Stewart G Griffin]

i know negative side of coil, i was just wondering if anyone had any tips because it's not a simple as plugging into the tach terminal on a more common hei cap.

[VileZambonie]

Well yeah it kinda is since it's the same thing... plugging into the cap is just making the connection to the - side of the coil.

Diagnostic Connector--If Equipped
Location - Mounted in the engine compartment on the left side front fender skirt, on some models.

Tachometer Connection - A tachometer may be connected between terminals 6 and G of the diagnostic connector.

NOTE: Since this is a full 12 volt system, no resistance wire is used.

NOTE: A tachometer connection is incorporated in the wiring connector next to the coil battery terminal on 4 cylinder models.

CAUTION: Never connect a wire directly between the Tach terminal of the distributor connector and ground as this will damage the electronic circuitry of the module.

NOTE: When using a timing light to adjust ignition timing, the connection should be made at the No. 1 spark plug--except when instructed otherwise by procedure.

CAUTION: Forcing foreign objects through the boot at the No. 1 spark plug terminal will damage the boot and cause engine misfire.
.

[Stewart G Griffin]

Just in case anyone cares, which nobody does:   In fiddling around and finding out more, the chevette carb is a holley 6510 which is simply the CCC version of a holley 5210, which in turn, is Holley's copy of a Weber 32/36 carb.   Holley was licensed to produce it.  i think Holley now owns weber.

So, it's essentially a Weber 32/36 carb.

Like the CCC quadrajets, the only thing that is computer controlled on the 6510 is the mixture control solenoid---the needles that move in and out of the jets.  And, of course it needs a throttle position sensor.

i don't think the distributor is computer controlled on a chevette which is good.