Need Help Please.....

[TurboXT]

I am having trouble with my brat, it has a little bit of hesitation or stumbling when the car is up to temp. around say....1500 rpms where the car wants to die out, but if you slam the gas to the floor, the car takes off smoothly, no probelms. Just for the heck of it I tried replacing the coil, that seemed to help a little bit, but it was still stumbling...I replaced the plugs with new NGK's, and it was still the same. So I noticed the distributor cap looked a little strange where it was sitting, so I started the car, and I advanced the timing......hesitation gone.....but THEN it made a loud sort of a cracking rattling noise like a pulley was gonna fly off or a belt was slipping as the revs get higher from about 3000rpm up.....is this knock?? Is it a carb problem?

 

Any help is good, as I know EA82's and ER-27's, but know VERY little about EA81's.

 

Thanks

 

Rick

[buru]

How exactly was the distributor sitting weirdly? If advancing the timing helped it, but then it got worse, you may have broken teeth on a timing belt, or broke altogether. Does it still start and run?

[Phizinza]

As far as I know. There is no timming belt on a EA81. TheEA81 is a push rod motor. (One cam in the middle above the crank, four little rods going to the rockers at each end of the head.) Does it still make the noise? Can you try and fine the exact location its coming from. Try using a screw driver with the tip on parts on the engine and the handle up agaisnt your ear. Maybe you have broken something in your dissy.

[Skip]

This problem sounds fuelish to me.

 

Full throttle (i.e. WOT) action rules out fuel pump or fuel filter.

 

Clogged jet in the carb - good bet.

 

Try a can of "Seafoam" (any good auto part house will have it)

 

Takes about a hundred miles to do it's magic

 

but

 

It is a proven winner for this type problem.

 

Hope this cheap fix helps

[TurboXT]

Yes, there is no timing belt. And what I meant by the disty. sitting weird is it looked like it was fully retarded, or close to it. It may need to be there, but like I said, I am not too familiar with the EA81.

 

 

It only makes this "ripping" sound when I am at WOT, as skip mentioned, so it's hard to tell where it's coming from.

 

I was driving it tonight, and it seemed to run fine one time, but then it seemed to run worse, and have some lag, and even a little surging the longer I drove it.

 

I will definatly try a can of "seafoam" thanks skip!

 

Thanks guys, and if anyone else has any ideas, please post them! Any help is good help!

 

Rick

[Bad Brat84]

As the former owner, I'll share some more history.

The dist. is in the current position as it was rotated to the position at which the brat would run the best. The distributor has been out and checked for bearings, etc and everything looked good. It is super easy to check the timing so use a light to play with it some.

What I found with it getting worse when warmed up is what you've noticed. It can be fully warmed up but until the heat get through all the engine it can run OK. If you turn it off, let it sit for like 10 mins and start it you can duplicate the problem easily. I honestly don't think it is internal to the carb as I played with the other carbs on the brat (the ones you have) and the problem was still there.

In the for sale post you will notice someone commented about an air leak at the carb base and that was where I was focused but not successfully. If you want to play around some more on this try spraying something like starting fluid (or something less flammable) around the base area (after warmed up) and you will see a change in RPM. I looked at the throttle shaft area also. Maybe a small crack in the intake manifold?

Try everything else you can though but here is a little more history for the others.

[TurboXT]

That sounds like it could be it too. I once had an EA82 carbbed wagon, but it had this air leak...and would backfire all the time. I am not getting any backfires, but like I say, I don't know the EA81 that great. I will try the starting fluid around the base though...sounds like it will work for detecting a leak. I did notice that the coolant was really low in the radiator, and the over flow was empty.....that may have had something to do with the problem as well. Still has decent power (for 70 HP), so I think the heads are ok.

 

 

Thanks

 

Rick

[subarunuts]

Sounds like you need to have a look at the accelerator pump on the carb - it enriches the mixture when accelerating off idle. If it does not function, then you'll get exactly the stumble you describe. If the carb has been apart, then good chance the little plastic ball bearing that acts as a check ball was lost and not replaced causing the pump to not function at all. Seen that before. Or the pump seal could be worn down from use. Either way a rebuild kit will have both parts for about $30 at most parts stores. Take the top off the carb and check under the long spring in the accelerator pump bore - the check ball is at the bottom - it's usually black or red plastic. Verify the float settings at the same time as stumbling could be due to improper settings. When reassembling make sure to check the float needle operation as they sometimes get worn and can stick in the open or closed position - best to replace those with new parts as well from the kit.

[TurboXT]

I am pretty sure the former owner (badbrat84) had it rebuilt a CCR as stated in his for sale post, but I am not sure when or anything like that. I'll try the carb/manifold gasket, and check for the accel. pump check ball. If CCR rebuilt it I am going to trust that the float level is properly set and all. I am starting to agree with badbrat more about the manifold leak, as that would make a giant vacum leak of sort......but I'll have to check it out and see what's up with it.

 

Thanks

 

Rick

[TurboXT]

OK, I think I have figured it out, but still need to drive it around to see if the problem still exists!

 

 

I decided to pull the carb off, just for the hell of it, and I found 1 gasket between the plastic spacer and the manifold, and no gasket between the carb and the plastic spacer. And in the bottom gasket didn't have a port cut out for that little coolant port twards the front of the manifold, and it was packed full of RTV. Also I found a hose that had a hole in it that and I pretty sure that is goes to the EGR valve.

 

SO, I made 2 new gaskets with gasket material, and cleaned everthing up, and re-mounted the carb. Also I pulled the PCV valve, it was fine.....but the hose going to it had some junk in it, and may have been plugged up.

 

That's what I found, but we'll see if it works any better.

 

I'll keep you posted!

 

Rick