Hot Start issue and Jumpy idle. Related?

[EXI]

Very cool. A 3rd Gen Site! Glad I found it as I am frustrated and new to my 3rd Gen.


I am stumped. I have a hot start issue on my 89 EXI with only 70,000 Miles on it.

Replaced over the last month:
-Fuel Pump
-Fuel Filter
-Distributor
-Coil
-Wires
-Cap
-Rotor
-Batt terminals
-Main Relay RZ-0028 (Tried two of them)
-Throttle body cleaned last night

When Hot outside temp 75f + She cranks but will not catch. After 6 attempts she will eventually catch. The shop I took it too said that when they diagnosed it had a weak spark that would come and go and that the fuel press was good.

Also at the same time I will be sitting at a traffic light at 900RPM. All of a sudden it will go up to 1100 and start pulling me. When I go to accelerate it stumbles and then goes. Does not happen at every light. Sometimes also when slowing down it will hicup.

Could the hot crank issue and the idle be connected? New to the EFI but in my early readings could it be the EVAC acting up? What does it look like?

I went to the wreckers today and noticed that all the PGM FI had this little box removed from them bolted onto the intake on the front. What is that? Mine has bang marks on it like someone pounded on mine.

My mechanic wants me to buy a new ECU but I am not convinced.

Help?

[InAccordance]

possibly... note the word possibly idle has to do with the idle air control valve.
It runs off engine coolant and if your coolant is low, will cause your idle to act ass whacked.
also, you can adjust the idle through it by taking to cover off the top with 2 phillips screws and using a coin, turing the thing inside it up and down.
all it does is allow air to pass through when engine is at idle to keep it running as your throttle body closes completely.
as for the hot start, i dunno... any number of things can cause that.

[kentwat]

You could check this thread a try to describe what is missing a little clearer.
https://www.3geez.com/forum/showthread.php?t=73490
Welcome.
Does it start just fine when its cold? I'd verify all grounds are clean and in tact also.

[Shilo]

I'd defiantly check into cleaning out the idle air control valve to help with your idle problem, but I doubt that would cause the hot start issue. Also check the coolant lines going to the idle valve for leaks.

[EXI]

Back to a heat wave today so back to trouble shooting.

Spark - yup
Fuel -yup
Injector pulse - yup

Unplugged the coolant sensor and put a paper clip in conector and voila.

Fired right up. Conicendence? Will report back.

When she cranks and cranks you can smell fuel. Almost like it is flooding out. I am hoping the sensor is buggered and it was flooding it out when it is hot.

With the paper clip in the connector the car thinks it is 100f out and not to add more fuel.

The Engine light is on and I have not tried a cold start yet in bypass but deffinalty interesting.

[Dr_Snooz]

Are you getting any codes?

[rc00netzero]

Sounds like a bad temp sensor or an air bubble in the coolant system - It seems it is a common issue. As I understand it, they can fail to register proper temp, but since the 3g ECU doesn't check for abnormal reading (like the temp sensor registering cold when the engine has been running for an hour), instead, it just watches for too high resistance. This means you can have a bad sensor and still not get a code 6. If the sensor reports cold engine when the engine and air temp are hot, the mixture will be set too rich (flooded engine) causing the hot start failure. Both the Intake air and coolant temp sensors increase resistance as temp drops, so by shorting the coolant sensor you told the ECU the engine was hot. Note: If your starting problem also happened when the engine had not been run for several hours (engine cold), but the air temp is hot, the intake air temp sensor might be the real culprit.

[rc00netzero]

I went to the wreckers today and noticed that all the PGM FI had this little box removed from them bolted onto the intake on the front. What is that? Mine has bang marks on it like someone pounded on mine

I'm not sure what that is - need a much better description, or a pic.

[EXI]

There were no codes when it was happening.

Cold start was always fine.

Sprayed extra fuel in the intake when hot an no go.

When starts up little puff of wht ( unburned fuel )

So still on the assumption of it flooding out when hot but need a couple of days of driving to confirm hot start is gone.

[EXI]

3 days of stop start driving at 95f outside.

Temp Sensor for the EFI replaced on Thursday.

I presume the computer was flooding it out when it was hot out.

So for those who have changed their RZ-0028 Relay and you still get a hot start don't over look the EFI Coolant sensor.

I will take it on a long drive tomorrow to see if it fixes the iratic idle. Checked the coolant level and it was good.

[w261w261]

Your coolant level can be ok and you can still have issues because of a bubble in the system. Are you a brand new 3G owner? If so, and you haven't bled the system, it's important to do so. The bleed valve is a small bolt near the thermostat and the Temp sensor. There's plenty of threads on here on how to do it, but be sure to let the little fountain go for awhile to get all the bubbles out.

Sounds like you replaced the TW sensor. That and the main relay are mandatory replacements at this point. If you're prowling the JY rip the driver's door panel off and get the window relay that's back there. I think it's white. The symptom of failure there is a window that goes down but not up. It will happen eventually to you.

[EXI]

Thank You W261. New owner of the 3G but learned to drive on my parents 3G when it was brand new. My parents have owned every gen Accord.

I own a TSX as well but I get more compliments on the 3G cause of the flip up lights. Everyone loves them. I know it is silly but it brings a smile to my face every time I turn on the lights at night.

Yup looks like the temp sensor was the failure in my case. It also affected my idle and hot start. Was cheap part too which was cool.

[nb0]

Cleaning the idle air control valve (IACV) usually does not work. You have to buy a new one.