42 replies to this topic

[TexanIdiot25]

I've got an '87 CRX HF, all stock and carb'd 1.5. Currently it has a missfiring problem when the motor is under load (high throttle or applying throttle in the lower RPM ranges of the higher gears). It comes and goes sometimes, but is usually pretty consistant. When I 1st bought the car, it was so severe that it could barely make the rolling freeway hills with out over heating and missfiring, but after a new rotor, and plugs (Cap did not fit, the pickups were rotated like 45 degrees...), the problem almost disappeared. Driving it around right after the tune up work, valve adjustments and tracking down the vacuum leaks and it drove fine. Started driving it daily now and the problem is still there, but no where near as severe as when I 1st bought the car. It's worse during the day when hot, and not near a problem at night when it's cold out. Plug wires seem fine, no arcing when sprayed with water, but what else would cause this? Are the emissions systems jacking up?

[enduser]

Change your wires. Just because you don't see an arc or short does not mean the wires are still good.
The wires need to be within a certain ohmns. They could be out of spec and worn out.
Change the wires.....

[EuphoricBlue]

Quick question, where do you have your vacuum advance lines hooked up to on the intake end?

[TexanIdiot25]

Quick question, where do you have your vacuum advance lines hooked up to on the intake end?

They are attatched to what seems to be the factory location. Though, not sure which one to pull off to check to see if it's actually working, and won't try it until I have some spare vacuum lines

[redsautorehab]

replace the cap and the wires. i have a brand new set of ngk wires in stock. $45 shipped. sorry, i don't think i can get the cap. my supplier shows three caps for 87, and all 3 exclude the hf model. i do have a cap for the non-hf, but i am not sure if it will fit or not. $3.50 extra if you want to try that cap.

[Bubba]

I agree that you need to change your wires too. There is a small chance that you need to replace the 5 wire oxygen sensor. What type of MPG are you getting? You should be getting in the 40's with mixed driving, 50's with highway driving- if you are only in the 30's and the misfire isn't very noticeable most of the time, then the sensor may be bad.

Does your upshift light work?


One more thing- In your original post you mentioned that you could "barely make it over the hills without overheating and missfiring..."

IMO- misfiring would have caused a loss of power, but it (a dead cylinder) should not cause overheating. When my head gasket was going bad and the engine was getting close to overheating, I developed some really bad spark knock misfiring (sounds like shaking marbles in a tin can).

Does it ever run hot now (more than 50% on the gauge or boil after a shut down? Or does it ever fail to suck coolant back into the rad as it cools down? (the rad should ALWAYS be full to the brim when cold) If so, you may need a head gasket.

[cbstdscott]

If changing the wires does not help.... check your cam timing.

Yes, I catch a lot of crap for making this suggestion. But if your timing belt is old there is a chance it has slipped a tooth causing ignition timing issues.

Scott

[Gabe87CRX]

Caps - http://www.rockauto....p;parttype=7120

Make sure you chose the right one.

Edited by Gabe87CRX, 27 May 2010 - 01:28 PM.

[TexanIdiot25]

replace the cap and the wires. i have a brand new set of ngk wires in stock. $45 shipped. sorry, i don't think i can get the cap. my supplier shows three caps for 87, and all 3 exclude the hf model. i do have a cap for the non-hf, but i am not sure if it will fit or not. $3.50 extra if you want to try that cap.

If you can compare them, the one I had had the contacts rotated 45* compared to the HF one. So, for example the contacts were placed in an X instead of +, for lack of a better explanation.

I agree that you need to change your wires too. There is a small chance that you need to replace the 5 wire oxygen sensor. What type of MPG are you getting? You should be getting in the 40's with mixed driving, 50's with highway driving- if you are only in the 30's and the misfire isn't very noticeable most of the time, then the sensor may be bad.

Does your upshift light work?


One more thing- In your original post you mentioned that you could "barely make it over the hills without overheating and missfiring..."

IMO- misfiring would have caused a loss of power, but it (a dead cylinder) should not cause overheating. When my head gasket was going bad and the engine was getting close to overheating, I developed some really bad spark knock misfiring (sounds like shaking marbles in a tin can).

Does it ever run hot now (more than 50% on the gauge or boil after a shut down? Or does it ever fail to suck coolant back into the rad as it cools down? (the rad should ALWAYS be full to the brim when cold) If so, you may need a head gasket.

Wires were on the weekend to-do list

Currently getting 37.3 mpg on the last tank, with this miss fire. This is with having to wring it out in 1st and 2nd to get up to speed with out putting enough load on the motor in a higher gear to missfire. Third as well, if getting on the freeway.

Upshift light works, seemingly properly

It started climbing to 3/4 on the temp gauge, that's when I would pull over and let it cool off. I know these Honda's habit of shredding head gaskets if over heated, so I stopped before getting the red. Other than that, I've been driving it for a bit over a week, with no cooling issues in this TX summer heat. I do pizza delivery, so if it was still an issue I would assuredly have ran into it last weekend, it's abit hard driving.

Rad is always full, at least the two times I've checked in the last week.

Caps - http://www.rockauto....p;parttype=7120

Make sure you chose the right one.

I ordered through RockAuto, actually. I believe it was a BOSCH cap, but the contacts inside were rotated 45*. This is the one with the terminals facing up, when installed, not to the side like stock. Don't have the part with me for the the Part # at the moment though

Edited by TexanIdiot25, 27 May 2010 - 02:36 PM.

[Madkore]

I would also suggest that you check your distributer vacuum advance with a vacuum gauge. to make sure it is functioning correctly.
The rubber diaphragm in the vacuum advance can crack and lose vacuum.

MK

[TexanIdiot25]

Would the quick and dirt method of unhooking the vacuum lines (and plugging them) to see if the idle changes, apply to this car?

[Bubba]

Yes- the idle speed should decrease when you unhook and plug the vacuum hose. If idle speed increases, then your advance diaphragm was bad and you plugged a vacuum leak (just leave the hose plugged).

[EuphoricBlue]

If you can't source it by the vehicle model, you might want to check and compare similar year Accord caps.

I was at a yard doing some distributor voodoo with an Accord and Civic DX distributor to make one working one, I wanted to use the Accord cap since the wire posts were lined up on the side instead of sticking out the top. (would make for better wire organizing) Well I couldn't use it on the DX because the posts were off, if memory serves correctly they were 45* off, otherwise the cap looked like it would mount.

[badpenny]

If changing the wires does not help.... check your cam timing.

Yes, I catch a lot of crap for making this suggestion. But if your timing belt is old there is a chance it has slipped a tooth causing ignition timing issues.

Scott

I have to agree with Scott on this. plus Euphoric, is dead on, there is a model (83-85) accord, SOHC that has a similar cap to the civic/crx, and yes, it is off by about 45 degrees difference. Easy way to tell, get the cap off, get the cam to TDC (align those marks on the cam to the head) while you are at it, check to see if the block is there too.

[Sinic]

What plugs did you use? Did you change to colder plugs? I see this a bunch with modular fords. Don't use the Bosch platinum +2, +3, and +4s. For some reason when they are used I see the same symptoms. Also when tuning my numbers are all over the board.