1996 honda passport has trouble starting when clutch is pushed in.If you try to drive it before the

Charles_61

When it’s cold and you go to start the car with the clutch pushed in if you leave the clutch pushed in it’s real rough idling and sometimes will bog down or just die. now soon as it turns over if you let the clutch out it’ll stay started until it warms up. If you try to drive it before the engine warms up it’ll just die soon as you push the clutch in! Any help would be awesome thank you

Mr_Shiftright

Do you also put the car in gear when this happens?

Charles_61

No that’s with it in neutral. As soon as it turns over you have to release the clutch or it will just keep on cranking and won’t start. As soon as it starts to sound like it might turn over you have to release the clutch. Then if it does start and is ideling if you push the clutch in at all it will bog down and die if you don’t release the clutch again. It will continue to do that until the engine gets to normal operating temperature. I know it sounds crazy but that’s what it does. After it warms up you are good to drive where ever you want. Thanks

Mr_Shiftright

This may be a case of correlation and not causation. Why don't you plug in a scan tool and see if anything is up with that. Also check for engine vacuum leaks, which will indeed seal themselves up sometimes once the engine gets warm enough. Vacuum leaks can certainly throw off the idle. I'd suspect the intake manifold as a possible source of leaks. You can test the seams with some carb cleaner or Brake Kleen. If you squirt in a certain area and the idle changes, you have a leak.

I'm thinking that maybe pushing the clutch in creates just enough drag on the engine to lower what is already a critically low idle speed.

Charles_61

Ok I will check that out! Thanks bud

thecardoc3

Do you know how to check the crankshaft end play? If the thrust bearing has worn it's possible that stepping on the clutch is pushing the crankshaft forward and away from the crankshaft position sensor causing the signal to drop out.

thecardoc3

https://forums.edmunds.com/discussion/55105/honda/passport/1996-honda-passport-has-trouble-starting-when-clutch-is-pushed-in-if-you-try-to-drive-it-before-the#latest

So I was wondering if you all saw this response from a few days ago and considered just how hard it was to figure out the first time any of us ever encountered similar failures?

Do you know how to check the crankshaft end play? If the thrust bearing has worn it's possible that stepping on the clutch is pushing the crankshaft forward and away from the crankshaft position sensor causing the signal to drop out.

Mr_Shiftright

Didn't think of that but it kinda makes sense---helluva lot of end-play though. ;

It does go to show that on old, high mileage cars, anything is possible and the weirdest things can happen.

I saw a similar symptom years ago---again on an old car. Know what it was? The clutch pedal was actually acting as a ground to the electrical system, so when you pushed the clutch in, you lost the engine-to-frame ground!

Not the first thing that pop's into your head, is it?

thecardoc3

I have seen that. That's one of the reasons that we preach test the right way each and every time.  In short (not a pun because it is an open ) I would see a command signal voltage go high and would quickly associate losing the ground with the clutch application . On a car lIke the OP here, seeing a loss of spark / injection command without an issue related to system voltage or the ground would have me concentrating on the ECM and it's inputs. What you find there is the ability to change the amplitude of the crank sensor signal voltage by stepping on the clutch pedal.

Mr_Shiftright

I had forgotten that even a Honda this old used a CKP--Honda was one of the very last holdouts to use carburation.

thecardoc3

Iirc, the Honda Passport was an Isuzu....

Mr_Shiftright

Yes, up to 2002--an Isuzu Rodeo