Engine is in ... Next question Options

[914_teener]

All yes basically

Others will chime in but....


Valves or timing would be my first quess.

Doesn't sound right.

[Amphicar770]

Just did the "spin test" on two of the pushrods and they pass. Too tired and frustrated to deal with the others right now. They are a major PIA to even reach with engine back in car as the exchangers are in the way and I have no desire to remove those and the muffler again.

I sure wish it had been something as simple as crossed plug wires. Any other simple checks? Could rotor be installed wrong? (I doubt it, just groping at straws).

Right now I am going, "Why did I sell the MR2 Turbo that never needed anything more than oil changes".

[914_teener]

Just read that you have a Pertronix.

Do you have a stock setup that you can throw in to rule it out?

[Amphicar770]

It has had the Pertronix (or equivalent) in there since before I bought it. No problems before I pulled the engine.

This morning I quickly connected timing light pick up to each plug wire and they all light up. Did not have time to check timing. I thought about putting old cap, wires, rotor back on but that seems like a long shot.

Unless some electrical but not connected I think everyone is right. Either ignition timing is way off or (more likely) I mucked up the valve adjust or reinstall of the rods (I was pretty certain they were seated properly but who knows). This weekend I will spin test the rods as suggested and check ignition timing.

I'll continue chasing down ideas anyone has so keep em coming. If I do need to pull the valve adjust assembly again it may be time to pay someone to do it. If I mucked it up with engine out, I doubt I will do better with engine in. If any of you who can do this in your sleep happen to be near collegeville, PA do let me know and I will gladly pay for your assistance. Else, there is a shop not too far that I can trailer it to.

Thanks for the advice and moral support!

[Dave_Darling]

A stock valve adjustment means that, when cold, the rocker arms will have play that you can feel when the cylinder is at TDC. So you don't have to try reaching the pushrods, just wiggle the rocker arms. If they wiggle, there is play. If they don't, then the valve is probably being held open.

--DD

[r_towle]

A stock valve adjustment means that, when cold, the rocker arms will have play that you can feel when the cylinder is at TDC. So you don't have to try reaching the pushrods, just wiggle the rocker arms. If they wiggle, there is play. If they don't, then the valve is probably being held open.

--DD

Sorry Dave but I will need to correct this.

You can adjust the valves with the pushrods not seated properly so the rockers feel fine.

If you would like to confirm that the pushrods are properly seated, you will need to see if you can freely spin them because if you do spin one that is not seated properly, it will fall into the seat....

But, I noticed you are about the bring it to a shop for the final setup....

[MarkV]

If you hooked a timing light up to each plug wire and got a signal then your problem is probably not spark. The engine sounds like its running on 3 cylinders, Try pulling plug wires off one at a time while it is running to see if you can isolate the cylinder. It could be that you have a loose connection on one of the injectors. If you have a push rod that isn't in the cup the amount of thread exposed on the adjuster screw should look different than the rest of them.

[Frankvw]

Try removing the wires to the plugs one by one when it is running, if it gets worse, place it back, not the one. If no difference ...check that cilinder/valves and/or sparkplug.-->in this case injector......injector seated properly ?

[ChrisFoley]

Pull the injector connectors out of the injectors one at a time while the engine is running.
They should each affect the rpm equally, except if one cylinder isn't firing.

[Amphicar770]

Thanks all. I will try the suggested (although probably can not get to it today). I will be a happy camper if it turns out to be something as simple as a loose injector connector!

[Dave_Darling]

You can adjust the valves with the pushrods not seated properly so the rockers feel fine.

Shoot, you're right! Completely spaced that aspect, which was the original thing we were talking about in the first place!!

--DD

[Amphicar770]

Hi All,

OK, new clue.

Just pulled the injector connectors.

Pulling #3 AND #2 had no change. Pulling #1 and 4 made engine want to stall.

Now, what does it mean?

Thanks,

Mike

[Frankvw]

Issue concentrated on 3 and 2. Check if spark reaches cilinder since you mentioned the wires itself had spark. Since the wires give spark (you mentioned that was ok )...it is after the distributor...so check injectors and sparkplugs first.
Get the plugs out and see if they give spark attached to their corresponding distributorwire.

[Amphicar770]

Just connected a spare plug to wire #3, started car and touched it to ground. That one is definitely sparking. Have not tested #2 yet. (Been sneaking out to garage while spouse yells, "are you ready to go yet").

[Frankvw]

You proofed the spare works...not the real one. :-)
Now...get dressed and make the wife happy !

[MarkV]

I don't know much about d-jet but I believe the injectors fire in banks of 2. I am not sure but I think the injection points in the bottom of the distributor control the pairs firing. You could have some problem with the injector points or the connector to the inj points or FI harness. Have you checked all of the injector grounds? Whatever it is it is probably something simple.

[stugray]

...

Did not see anything unusual when I removed valve covers. Rods are seated in rockers. I did not rotate engine but some have play, others do not as would be expected based on engine position. When I did do valve adjust, none were off by very much.

Did you actually perform the valve adjustment procedure when you adjusted them?
I would say that proper valve adjustment is key.
It would help you diagnose if there is a real problem and costs the least $$.

So you have been running it on & off, but is it still backfiring, or did it only do it a few times?

[Amphicar770]

Yes, I did do valve adjust after I replaced the rocket rod "tubes" and reinstalled rockers.

I have only run it briefly a few times. It has not backfired at idle since the first couple of times but did have some when I press accelerator. Missing is definitely still there even without backfire.

[stugray]

Yes, I did do valve adjust after I replaced the rocket rod "tubes" and reinstalled rockers.

I have only run it briefly a few times. It has not backfired at idle since the first couple of times but did have some when I press accelerator. Missing is definitely still there even without backfire.

And what did you use to identify Top Dead Center (TDC) when you set the valves?
Was the distributor installed and did you verify where it was pointing when you were at TDC #1?

[Amphicar770]

Yes, I did do valve adjust after I replaced the rocket rod "tubes" and reinstalled rockers.

I have only run it briefly a few times. It has not backfired at idle since the first couple of times but did have some when I press accelerator. Missing is definitely still there even without backfire.

And what did you use to identify Top Dead Center (TDC) when you set the valves?
Was the distributor installed and did you verify where it was pointing when you were at TDC #1?

Yes, used distributor, flywheel marks, straw in cylinder. I was pretty paranoid about having it right. Most of the valves required very minimal if any adjustment.

That said, it was first time ever adjusting valves son the possibility that I mucked it up is always there.