Missing

[Bigg_Billy]

Hello,

I have a 1988 Honda Accord with 185,000 miles. I just put a new head gasket in, wires, plugs etc. Before I started it had just started missing, and after all the work it is still missing. Compression is pretty good, all around 130 psi. Where should I look next? Manual says "missing at idle" and "missing at all speeds" that the EGR might be at fault. What do you folks think?

Thanks,

Bill

:uh:

[mouchyn]

you just put a new headgasket on and the compression is only at 130 psi? i sure hope your gauge is reading wrong. If your gauge is accurate, then your compression is WAY low. Like, out of spec, low. That could either be messed up valves or your rings.

describe the scenario when your engine would miss. that could help us track it down more.

[Bigg_Billy]

Actually it's my son's car and you know how the lines of communication can sometimes be. When I came upon it, it was missing at idle and throughout, and he was loosing antifreeze and didn't see any leaks. So I put in a new head gasket. Agreeably I should have done other work but the car had been running fine *(and we didn't have the $), until it just started missing. Also I just found the thermostat stuck wide open yesterday, so i'm going to put a new one in tonight. I'm wondering if that is connected to the missing as well, as I noticed a vacuum sensor valve on the thermostat housing.

Bill

[mouchyn]

when was the last time you did a normal tune up?
is this a carbed accord or a fuel injected accord?

continue the tune up:
distributor cap
rotor
fuel filter

if you have a multimeter, you can test the ignition module and the ignition coil.

was the 130psi compression even across all pistons? what were the individual compression test results?

[Bigg_Billy]

Carb Model, just put on cap, rotor, wires, plugs, 1@135, 2@140, 3@135, 4@145. Haven't done a fuel filter but it runs fine at full throttle, just misses at idle or when you back off while shifting. Would agree my compression gauge may not be the best, but the pistons are all fairly close. Oh and there is a good spark, 3/4" no problem.

[NXRacer]

could be your rotor. if you replaced it with non-honda replacement parts that could be the problem to your missing idle. Another member elightened me to the fact that aftermarket rotors arent as good as OEM honda ones and can cause you to have a bad idle. I replaced mine with one from the autostore and i'm pretty sure its giving me a miss on idle too. I'm gonna go down and get an OEM one as soon as i get paid and see if that makes a difference.

[Bigg_Billy]

Checked the EGR valve last night and it is good. The manual mentions vacuum leaks as a reason for missing, I've checked around but can't see a problem. Could the PCV be causing loss of vacuum? Been reading a little, could a bad distributor cause this type of problem?

[Bigg_Billy]

I need help. 1988 Accord atuo, carb. 185,000 mi. The car was running good but antifreeze was disappeariing, and the car recently starting missing at idle and through all ranges. Took a compression test and all cylinders were around 140. Figuring it was the head gasket, I removed and installed a new one. Head wasn't cracked or warped. Put it back together with new plugs, wires, and it is still missing. Removed the EGR and it is working fine. Did notice upon looking around and pulling off hoses that there wasn't much vacuum to be had. Notice the thermostat housing vacuum sensor was open, didn't know if it should be shut until the car warmed up? Going to check the PCV and check the valve lash adjustments? I don't know, where else should I be looking? Been reading a little, could a bad distributor cause this type of problem?

Thanks,

Bill

:werd:

[mouchyn]

yes to the PCV

yes to the distributor.

check 'em out

[A20A1]

I combined your "Missing" threads.

[A20A1]

Notice the thermostat housing vacuum sensor was open, didn't know if it should be shut until the car warmed up?

It's a thermovalve... it's not a vacuum sensor but a coolant sensor.

The thermovalve on the thermostat should be open when cold, this bleeds vacuum. Then when the motor warms up it should be closed.

You also said you didn't nottice much vacuum... the amount of vacuum will be determined by the seal of all the gaskets... the demand of the motor and the amount of throttle... and lastly where you plug in to get the reading.

Manifold vacuum will be high at idle when the throttle is closed... around 24"
at the same time venturi vacuum which are usually ports found in the center of the carb body will pull much less vacuum.

Add more throttle and manifold vacuum drops and venturi vacuum increases.

[Bigg_Billy]

Well I replaced teh PCV and things got better, but they ran a lot better when I blocked the PCV altogether. I'm going to do a vacuum test, but in reading up about PCVs, they mention that exccessive blow by can really effect vacuum by pushing a lot of pressure through the PCV diminishing vacuum. So at 185,000 miles I may be needing rings.

:sad2: