Throttle problem

Hi ViperKing,

I think your timing is part of the issue. Looking at the spec it should be between 8-12 degrees BTDC. If you are sitting at 1 then that would cause a lag in acceleration.

We always set timing as close to spec as possible first then adjust the carburetor. If you are setting the timing at 1 degree because that is where it runs the best, that is great but your carburetor is not adjusted. So you need to set the timing around 10 degrees to start and then adjust the carburetor so that it runs better. If you need to go +/- 2 degrees after that to get it to run really well then that it fine.

If you timing is not right then this is why you are not getting much change from your carburetor settings.

The progression should be timing, idle speed, air/fuel setting for smoothness, then go back to timing if needed to get that rolling idle.

Let me know what happens after this and we can go from there.

My timing is at 12 with the vacuum advanced hooked up, 1 with it unhooked.

Yeah. You want it at 8-12 base timing. That means you set it with the advance unhooked. Then the vacuum advance will set advance it the amount it needs. The spec is 8-12 base timing and having it that low will cause a lag in acceleration.

The only other thing that will cause a lag on acceleration is the carburetor is not adjusted properly or the carburetor passages are clogged or restricted.

Again, I would set the timing more advanced than 1 degree because your combustion is happening just as the piston is coming to top dead center. This will do two things, cause the engine to be less efficient and down on power due to not maximizing the power from the combustion because the piston is already traveling down before the expansion of the combustion takes place.

You want the ignition to ignite the air fuel mixture about 10 degrees before top dead center so that as it begins to ignite as it finishes compressing and then really explodes as the piston begins to go down.

Also, if the ignition happens to close to TDC then it will actually push the piston down at TDC which will damage the crank bearings.

may I ask where you're getting those numbers from? My Haynes manual says to do it based off of a sticker under the hood but there is no sticker and everything I've read has said between 0 and 5.

I got the information from Alldata. Even if Alldata is wrong 0-5 is very low. I would suggest trying it as I stated above because you aren’t going to hurt anything. Worst case we put it back to where you have it and try something else. However you said yourself that you can adjust the carburetor to make any difference. Normally that is because timing is off.

Let me know what you find and we can go from there.

Well I set the timing to 12, it's got better response but it's still got a miss at idle and surges. Any idle below 900 is horrible. I put the idle fuel mixture back to factory settings.

Also something I forgot to mention, the engine is estimated to be a 1985 model and I did my best to keep all the engine components around that year. I was able to do it for the most part except for the solid metal vacuum lines, those are from an 1980. My friend also wanted to due away with all of the emissions stuff so we did, I did my best to block off everything except the distributor, the booster, and the charcoal canister. It does have an EGR and I've tried running it with and without it connected to vacuum. With how many vacuum connections the carburetor has, could misplaced vacuum lines be an issue? I've looked at countless vacuum diagrams but cant find anything close to the set up he has in his truck. Are there certain things that need to be connected? If so could I run them to straight vacuum or do I need the different jets and valves in between?

Oh boy. The misfire and surging based on all that definitely sounds like a vacuum leak. However, let's just start at the basics and hook up a vacuum gauge and see what the needle is doing. It should be very steady and not bouncing at all. If it is moving around, get a video of it and send it over so I can see what it is doing and we can go from there.

If it is steady then we can move on from a vacuum leak and look at the EGR operation and canister. If you still have that hooked up, do you have a purge valve or did you eliminate it?

Vacuum has stayed very steady between 17-21 (depending on idle) goes down and back up smoothly on acceleration, spikes cleanly when letting off, so I know there's no leaks.

There's no purge valve anywhere, EGR has one port, EGR filter has two ports, canister has two ports, distributor has two, and carburetor has twelve if I'm not mistaken.

Okay. Just to clarify. When the vehicle is idling with the current issue you are having, what does the needle do? Can you send a video of it just idling?

Next time I'm with the vehicle I'll see if I can get a video to send. Also something else that slipped my mind. The engine does run very well when I restrict half of the air flow into the carburetor, however the idle spikes dramatically when I do so, and adjusting the idle doesn't lower it.

And while thinking about it my friend did remove the gas tank to clean it out and replace the hoses. I wasn't around when he did it, and I know he hooked the fuel line up to the wrong pipe, and he used to much extra hose making it very difficult to fallow where the others go to see if they are hooked to the correct lines or not. I know one goes to the canister, two go to the pump, and I'm not sure what the fourth one goes to, he said there was only three connections on the tank, but there are four lines going back to it.

Okay. So we have a lot of things that need to be tracked down. If blocking off air causes the engine to run better that means you are getting to much air from other places which would indicated a vacuum leak. So the video of the vacuum gauge at idle will help confirm this.

As for the lines to the fuel tank, one may be a vent line however, we will need to get your friend back over to run through that with you just to confirm what each are.

I tried asking him where they all went and he had no idea, he just connected them where he thought they went.

But if it has a vacuum leak, why wouldn't it idle down with the screw all the way out and the air flow restricted?

I was wrong, vacuum gauge was lying to me. I noticed the tube I was using had collapsed in on itself under vacuum and wasn't reading properly. now the needle is vibrating rapidly between about 17 and 22.

Oh yeah. So that needs to be perfectly steady before we can do anything else. That is why you are not able to adjust the mixture screws and make any change. Plus, that is affecting your idle issue as well.

Obvious statement is we need to plug all vacuum leaks and then go back through the setting timing and adjusting carburetor.

I plugged all vacuum connections except for the vacuum advanced, the timing stayed the same and the needle is still fluctuating.

Okay. If there are no vacuum leaks then this seems like a valve issue. Worn valve guides will cause the rapid fluctuation like this but you said you just rebuild the engine. Did you replace the valve guides?

Before you do anything else with this, monitor the vacuum gauge and then retard and advance the timing back and forth and see where the needle becomes steady. There is a chance that timing could cause the fluctuation so this is the old school way of setting timing, by using a a vacuum gauge.

Head was new from the machine shop, new valves, seats, springs etc. Just checked valve adjustment and a few of them were off, got them all readjusted with the engine hot, about to fire it up and see what happens .

Went to start it and the battery died almost immediately, ran through a rabbit hole of diagnostics. going to have to get a new regulator tomorrow and try again.

Okay. Just post an update whenever you have one. I will wait to hear back. Thanks

New regulator didn't help, there is an issue in the wiring harness, put in a internal regulatory alternator and got the charging system going good. Got it started up, tried adjusting the timing. All I got was higher or lower vacuum. The needle would start to calm down while moving the distributor, but after letting it settle the fluctuations would go back to the same as before.

I checked valves for any major play in the guides. All of them were very tight with no noticeable movement.

Also I've noticed when I plug and play different vacuum connections on the carburetor to different vacuum tubes the needle either gets a little steadier or much worse.

Okay. You want to take your reading from manifold vacuum after the carburetor. Can you hook into one of those vacuum lines and resend the video? If that gauge is acting differently then that explains why your guides appear to be okay.

It is connected to direct intake vacuum, I think it may be changing with the fluctuation of rpm.

Okay. Yes if RPM is ranging then vacuum will as well. However, I just re-watched that video of the vacuum and that is swinging wildly and the RPM sounds steady.

Can you send me a new video with your timing set around 8 BTDC and at idle and lets see what it is doing?

Basically, things just are not adding up that if you don't have vacuum leaks and the valves are not the issue then we are missing something in the conversion from one engine to another.

With or without advanced hooked up, and what rpm would you like to see it set to?

Okay. I have to back track a little because I just realized I have been looking up specs for a 1980 2.4L but you said you have a 1985 engine, correct?

So for a 1985 2.4L 144.4 22R-E engine the base timing spec is 5 BTDC and for a 2.4L 22R engine it is 0 BTDC.

Do you know which you have? If not, I would set it at the more advanced number because you said it seemed to run better with more advance.

You always set base timing with the advanced unhooked.

So I attached the chart for timing on the 22R engine which says it should be 0 BTDC at 600 RPM.

For the 22R-E engine it says 5 BTDC at idle and idle spec is 750 RPM.

The next document is the timing advance specs. You should not need to adjust this but you can check your advance is accurate. So set your base timing and then run the engine at 2500 RPM and you should see the timing with the range of the last column.

This also has your distributor number on it which should help identify which engine you have. Clearly it is going to be a 2366cc engine but I don't know which one to tell you to look at so you will need to look for the ID number on the distributor.

This is all to get your timing set properly. Once it is set, send me a video of the vacuum gauge and we can go from there. I hope setting this timing properly will resolve most of this issue but we have to try and "back door" this to figure out which engine you have. Let me know and we can go from there.

Sorry for the confusion.

Sorry for the multiple posts but I just found the actual procedure for a 1985.

Give this a read and let me know what happens.

That's the original way I had it set, it's a 22r, re is the fuel injection version. I originally had it at about 1 degree with no advanced, and a total timing of 32 at about 3k rpm, it sits at 12 with advance connected. But only when its connected to manifold vacuum, when its connected to the carburetor it doesn't advance any. I know you always set the distributor with the advanced unhook, but I didn't know if you wanted to see the vacuum with it hooked up or not

Oh. Ok. Yes. Vacuum reading with it hooked up. Thanks

Welp, ended up getting rid of the OEM carburetor in exchange for a Weber 32/36, set the timing to about 2 deg, that's where it seems to like the best. And now its running beautifully, it still has the shaking vacuum needle, but at this point he doesn't want to sink the money into redoing the whole top end, especially with how much he's already had to put into the build, the needle did steady out a little bit and is now only shaking back and forth between about 4 in hg

Ok. Great job. That makes sense. It was a vacuum/air leak but just not in the area we were looking. I am sure there is something else leaking but as you state, if it is running well then i wouldn't worry about it.

Thanks for the update and using 2carpros.