Shaking / Bogging Getting Worse, Has Me Worried

[Sean]

Driving with my grandpa today, 60-70 degrees F outside, car is stone cold on start.
Car is fine until temp gauge shows one eighth up from C.
Car bogs at 2.1 k rpm in any gear and or speed. Slowly slows down because i can’t accelerate (going about 35 mph) because any throttle input during this time leads to the car actually decellerating and just a touch more throttle leads to shaking of car, like engine pulls hard, then engine brakes, then pulls hard, etc.
Once car heats to normal temp normal operation resumes.
In 100 F + weather the car did a similar thing on the highway with a horrid exhaust leak / sound that never happened again as of yet.

This did happen before often when the car is warming up then its gone almost instantly (going 45 mph in that instsnce) but this latest one threatened to make the car undriveable.

Any ideas?

Topic

[Greg]

Major misfires or plugged exhaust or low fuel pressure come to mind

[Sean]

[quote=”gmule” post=159072]Major misfires or plugged exhaust or low fuel pressure come to mind[/quote]

Could this be timing belt related? Also found out this motor has the egr port cover that i can clean out. Low fuel pressure, i get how that would cause an issue, however why would it depend on engine temperature? Will need to buy vacuum gauge for that exhaust check…

[EricTheCarGuy]

I don’t recall seeing where you listed year, make, model. That would be a good start. From there are there any check engine codes?

I’d forget about the timing belt and EGR and work off the evidence you’re presented instead. I cover the procedures here.

http://www.ericthecarguy.com/faq/solving-automotive-performance-issues

Good luck and keep us posted.

[gabe collins]

I’d start with engine codes and even if possible live engine data

[Sean]

[quote=”EricTheCarGuy” post=159106]I don’t recall seeing where you listed year, make, model. That would be a good start. From there are there any check engine codes?

I’d forget about the timing belt and EGR and work off the evidence you’re presented instead. I cover the procedures here.

http://www.ericthecarguy.com/faq/solving-automotive-performance-issues

Good luck and keep us posted.[/quote]

Oh i thought leaving it in my signature would be ok, its a 94 accord LX 4 door.

I have read that info linked there before, so I’m guessing I should find out which system is the cause.

However, my real issue here is that I am stumped on what could even cause this tiny window of issue. Its only at one temperature range that this happens. The car has an OEM thermostat that I myself installed so it comes up to temp quite quickly. Therefore passing the tiny temperature range really quickly. I was hoping that I could be pointed to the system that could cause such an issue.

[Sean]

[quote=”sisterwillys1940″ post=159111]I’d start with engine codes and even if possible live engine data[/quote]

no engine codes its OBD1 Honda 94 Accord, so shorting out the connector just leaves the light on no flashing.

[Sean]

I think what the best course of action here, because I cannot replicate this problem unless the car is moving, is to take a video of me driving until it starts happening and quickly pull over before it heats up to check around for certain things. Will do that right now, in fact.

[Sean]

Took a video, it happened very shortly. You can also hear quite well the exhaust leak/rattle I have been trying to find.

I am hoping this could shed some light on this issue. If not and you wish me to check a certain system, just tell me and I will use my FSM to do a full diagnostic on that system. Currently i have 0 clue where to start beside exhaust restrictions, I saw your video on that so all I need is a vacuum gauge.

[video]https://www.youtube.com/watch?v=5Z3UQcazaL8[/video]

[zero]

What kind of shape is the ignition system in?

You mentioned something about an idle valve? It’s a good idea to fix any known issue before going after other issues. Even if they don’t seem related, they may be.

[Sean]

[quote=”DaFirnz” post=159136]What kind of shape is the ignition system in?

You mentioned something about an idle valve? It’s a good idea to fix any known issue before going after other issues. Even if they don’t seem related, they may be.[/quote]

I just replaced rotor, wires, plugs, (NOT CAP YET), and all oil seals in the distributor.
Dist and rotor are both Honda OEM, Tek kind.
Wireset and plugs are now NGK iridium (they were cheaper than the copper)
^ this improved my idle IMMENSELY. However i did notice alot of slop on the distributor bearing… I might have to go buy a new one from the junkyard.

Idle air control valve was dirty from a botched air-filter by the previous owner. I resolved that and cleaned the intake as best I could.
Idle was incorrectly set, I followed the Honda procedure to set it correctly. 750rpm when warm.
The part I was referring to was the fast-idle-valve it is improperly set, being too quick to let the idle down on warm ups.

Only thing I can think of on this car is when I was timing it how the distributor even on full clockwise rotation, is still 5 degrees off of the red mark.
Also of note, when timing I noticed the red mark would jump up and down, aka wouldn’t be in the same spot every time.

The ECT sensor for the ECM (plug under the distributor, two prong) when I was taking the dizzy out to replace oil seals, I found the previous owner had cut off the sensor’s connector, and twisted and taped two spade connectors on, I couldn’t afford to get the connector from the junkyard at the time, I am going tomorrow to the JY to get more parts for my car. Muffler included. (hoping to cancel that exhaust rattle / leak.

I was gearing up to do a timing belt seeing as how the dizzy was not adjustable into-spec. However this issue takes precedence now because of how it affects the driveability of the car.

Of note: only time this happens it seems is:
accelerating near 20-40 mph.
car is just past the C on temp gauge, warming up.
taking or taken a right turn.

Possible fuel starvation from fuel pump comes to mind, happened on my 97 Neon, however that is not a temperature dependent item.

[Sean]

Well I guess since I can’t even afford the vacuum gauge now I am just going to let this slide.
Thanks for all the help i guess…

[EricTheCarGuy]

Don’t mess with the timing as I don’t believe it to be a timing related problem. If it was, it would be a problem all the time. Since it’s temperature related, and you have issues with the coolant temp sensor wiring, I would say that’s your prime suspect. I’d do what I can to make sure that sensor is functioning properly and that the cooling system is free of any air. Air in the cooling system can upset the coolant temp readings.

BTW the coolant temp sensor is extremely important when it comes to calculating the fuel mixture. A malfunctioning sensor, or improper signals to the computer from the sensor can cause the problem you describe.

[Author]

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