Car runs very badly (and dies) when it warms up/cooling fan turns on (SOLVED)

688 Views 26 Replies 6 Participants Last post by mossin_90, 15 d ago

noahec2000

Discussion Starter · 1 mo ago

Hello everyone first post on this forum, coming from the club xterra forum

would like to say I tried searching for some solutions but still confused as what it needs to fix this particular issue. so ill start with some context

bought a 91 crx si with the original motor, and for the most part it would turn on and stay on rather well, old owner stated it ran "a bit rich"

First three weeks were solid motor wise, despite the idle going down for a second then coming back up quickly, it pretty much never died, unless i stalled it because i suck

FRIDAY- While leaving college in the morning, somebody throws a tangerine at my windshield (don't ask why), so i peel out pretty hard, not a clutch dump, but pretty close, i lost traction. Car ran normally and never really died. Later that night while driving up to LA, i noticed a bogging, detonation, misfire? sound while the motor was under any load, not catastrophic, but noticeable. The on the way back to OC, same thing happens. during warmup, it drives beautifully, but once hot it bogs a bit.

SATURDAY- Heading back up to LA to a friends house to install a hybrid racing short shifter, bogs/misfires/detonates? even worse than it did on Friday (after warmup), didn't die on freeway because i kept up the speed. it only died when i got off the freeway. It would not even hold idle anymore. Temperature was good, had plenty of fuel, just was not running right. Limp it to the house and find out it threw code 3 for the map

SUNDAY- we put an ebay MAP on it and it still runs really badly, it then threw the code for the EACV, which we proceeded to clean with carb cleaner. attempted to do idle relearn, but it just isn't happy when the car gets hot(not driving) especially when the fan turns on for the radiator, it basically kills it at idle

My friends are pretty competent mechanics, but the car is fooling us and not giving us any clues we could put together. Just wanted to hear what yall think the issue could be. I was thinking it hooped the timing tooth but that seems unlikley, but at this point ill try anything out

Thank you very much, i look forward to posting more on the forum

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mossin_90

· #2 · 1 mo ago

Welcome to the community
There are a few things to check.always start with the cheapest alternative first.

If your problem is idle, check:

1. Idle Air Control Valve, test it with 12vdc, and make sure it's clean.

2. Inspect distributor cap and rotor for signs of tear and wear specially that white= grayish caked over the DC contact pins.clean the rotor/button as wel. If you see its all beat up replace them both with new parts.

3. Check timing as well, SI marks on the cam gear is read at a different position than a Dx/ base model. SI top dead center mark is at or around pointing to 7:00 clock position.

4. Chances are the Fast Idle Throttle Valve(FITV) might need adjustment.

5. Don't forget to inspect and clean ground terminals at battery and chassis and transmission.
There are plenty of posts related to all those points I mention, and chances are you will see a few vids on YT as well.

Gl

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noahec2000

Discussion Starter · #3 · 1 mo ago

mossin_90 said:
Welcome to the community
There are a few things to check.always start with the cheapest alternative first.

If your problem is idle, check:

1. Idle Air Control Valve, test it with 12vdc, and make sure it's clean.

2. Inspect distributor cap and rotor for signs of tear and wear specially that white= grayish caked over the DC contact pins.clean the rotor/button as wel. If you see its all beat up replace them both with new parts.

3. Check timing as well, SI marks on the cam gear is read at a different position than a Dx/ base model. SI top dead center mark is at or around pointing to 7:00 clock position.

4. Chances are the Fast Idle Throttle Valve(FITV) might need adjustment.

5. Don't forget to inspect and clean ground terminals at battery and chassis and transmission.
There are plenty of posts related to all those points I mention, and chances are you will see a few vids on YT as well.

Gl

Thank you, I'll give all of these a look

Will post back when resolved

jwharnish

· #4 · 1 mo ago

noahec2000 said:
Hello everyone first post on this forum, coming from the club xterra forum

would like to say I tried searching for some solutions but still confused as what it needs to fix this particular issue. so ill start with some context

bought a 91 crx si with the original motor, and for the most part it would turn on and stay on rather well, old owner stated it ran "a bit rich"

First three weeks were solid motor wise, despite the idle going down for a second then coming back up quickly, it pretty much never died, unless i stalled it because i suck

FRIDAY- While leaving college in the morning, somebody throws a tangerine at my windshield (don't ask why), so i peel out pretty hard, not a clutch dump, but pretty close, i lost traction. Car ran normally and never really died. Later that night while driving up to LA, i noticed a bogging, detonation, misfire? sound while the motor was under any load, not catastrophic, but noticeable. The on the way back to OC, same thing happens. during warmup, it drives beautifully, but once hot it bogs a bit.

SATURDAY- Heading back up to LA to a friends house to install a hybrid racing short shifter, bogs/misfires/detonates? even worse than it did on Friday (after warmup), didn't die on freeway because i kept up the speed. it only died when i got off the freeway. It would not even hold idle anymore. Temperature was good, had plenty of fuel, just was not running right. Limp it to the house and find out it threw code 3 for the map

SUNDAY- we put an ebay MAP on it and it still runs really badly, it then threw the code for the EACV, which we proceeded to clean with carb cleaner. attempted to do idle relearn, but it just isn't happy when the car gets hot(not driving) especially when the fan turns on for the radiator, it basically kills it at idle

My friends are pretty competent mechanics, but the car is fooling us and not giving us any clues we could put together. Just wanted to hear what yall think the issue could be. I was thinking it hooped the timing tooth but that seems unlikley, but at this point ill try anything out

Thank you very much, i look forward to posting more on the forum

You say on Sunday we put an eBay MAP on it. These cars are not normally tunable. What ECU are you using? You check plugs, or O2 to see if they are rich?

noahec2000

Discussion Starter · #5 · 1 mo ago

jwharnish said:
You say on Sunday we put an eBay MAP on it. These cars are not normally tunable. What ECU are you using? You check plugs, or O2 to see if they are rich?

We just put a working OEM MAP in because it threw that code when it died, as far as ecu goes it's the original one as far as I know

We popped some new plugs in for sh*ts and giggles but the old ones looked fine

The O2 sensor looks new, but that all I know about it, I didn't pull it off just peeked at it

msc

· #6 · 1 mo ago

My top guess is that the timing belt jumped a tooth or two. This is known to happen some times under a hard acceleration.

Unless you know for sure the timing belt has been replaced in the past 10 years or 75K miles you should plan on replacing the timing belt. You will also want to replace the tensioning pulley and spring along with the water pump at the same time.

Mike

Reactions: 1

noahec2000

Discussion Starter · #7 · 1 mo ago

msc said:
My top guess is that the timing belt jumped a tooth or two. This is known to happen some times under a hard acceleration.

Unless you know for sure the timing belt has been replaced in the past 10 years or 75K miles you should plan on replacing the timing belt. You will also want to replace the tensioning pulley and spring along with the water pump at the same time.

Mike

Waiting for the weekend to arrive to do all this. Thanks for your response

The belt was my guess too

noahec2000

Discussion Starter · #8 · 25 d ago

Well I finally got around to working on the car today, and was about to check the iacv but now she won't even start cold, had no luck getting her to start

The main relay seems fine I hear the fuel pump and a click

I also wanted to ask if the d16 motor has a FITV, I didn't see a hole for it in the throttle body so I'm guessing not

Digging deeper

noahec2000

Discussion Starter · #9 · 23 d ago

I have excellent news regarding my car

Got home and measured the EACV across the pins, 11 Ohms(passed 8-15)

No continuity between EACV case and pins (good)

Have 12 volts at the connector with key on and no volts when key off, that checks out too

New O2 sensor installed

Rebuilt distributor with duralast coil, rotor, and cap(note these parts)

I went to start my car and it literally jumps to life in a quarter of a second, so that was great

Did the idle set procedure and it sits just fine at like 700 ish

Went for a test drive and all seems to be perfect, no more misfiring under acceleration, holds idle perfectly, even the rpm needle doesn't jump like crazy, until...

I do a reasonably hard pull (what started this whole problem in the first place), and boom, car is shaking under acceleration and seems like it's misfiring like before, but it would still hold idle thankfully

Lady's and gentlemen, I believe the problem was the distributor the whole time, because I literally recreated my problem by accelerating hard (I'm like 80 percent sure)

Do these duralast parts, distributor wise, just not last? I guess not

I will tear apart the distributor tomorrow and share my findings. Hopefully I find that it's beat up and broken, cause that will basically solve my problem

Thoughts and opinions and appreciated

Thanks

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ale5six1

· #10 · 23 d ago (Edited)

mossin_90 said:
If your problem is idle, check:

1. Idle Air Control Valve, test it with 12vdc, and make sure it's clean.

2. Inspect distributor cap and rotor for signs of tear and wear specially that white= grayish caked over the DC contact pins.clean the rotor/button as wel. If you see its all beat up replace them both with new parts.

I second checking these 2 items from Mossin, as my CRX has had bad idle/misfires for these reasons over the years.

And I'll add a 3rd option, check for small coolant leaks as they can cause inconsistent idle as well. Mine was a small hose that looped over the intake and went from the block to another hose and it had a small leak at a connection point.

4th idea, try to bleed air out the cooling system. This is done by parking on a uphill driveway and running car with radiator cap off and squeezing all the coolant hoses you can find to push the air out of them and into the radiator. ( you may have to do a couple heat cycles of this, to get all the air out)

Reactions: 1

mossin_90

· #11 · 22 d ago

Have you made sure the engine is not flooded.

if it smells like raw fuel at the tail pipe after a few cranks check for a stock open fuel injector, bad fuel pressure regulator( make sure its vacuum hose is tight) or bad engine coolant temperature senor.

Reactions: 1

noahec2000

Discussion Starter · #12 · 22 d ago

mossin_90 said:
Have you made sure the engine is not flooded.

if it smells like raw fuel at the tail pipe after a few cranks check for a stock open fuel injector, bad fuel pressure regulator( make sure its vacuum hose is tight) or bad engine coolant temperature senor.

I do smell fuel, but I suspect my test pipe is the reason why as it's not absurd

If my distributor is not at fault for the issue at hand, I'll be sure to check these items (although I couldn't find ANY vacuums leaks)

Thank you for your 2 cents

mossin_90

· #13 · 22 d ago

Pull spark plugs and see if they are fouled. All full of black soot.

noahec2000

Discussion Starter · #14 · 22 d ago

4

Gas Font Automotive tire Vehicle Auto part

Tire Automotive tire Bicycle tire Bicycle wheel Bottle

Automotive tire Bicycle tire Automotive lighting Rim Writing implement

Gas Auto part Rim Metal Bicycle part

mossin_90 said:
Pull spark plugs and see if they are fouled. All full of black soot.

Inspected cap and rotor, seemed fine

Test drove and it stalled after 30 minutes of city driving

waiting on my ngk coil to basically rule out distributor

Wires look good, no corrosion on either side

I pulled the plugs, and I have photos, these only have about 30 miles on them (replaced when first encountered my troubles)

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ale5six1

· #15 · 22 d ago (Edited)

noahec2000 said:
I do a reasonably hard pull (what started this whole problem in the first place), and boom, car is shaking under acceleration and seems like it's misfiring like before, but it would still hold idle thankfully

Lady's and gentlemen, I believe the problem was the distributor the whole time, because I literally recreated my problem by accelerating hard (I'm like 80 percent sure)

Being that the idle is good and it hesitates or misses only under hard load, AND b/c it stalled after warming up, I am heavily leaning towards distributor (I had the same exact problem before)
b/c you inspected the distributor and it seemed okay, I would try a new set of spark plug wires from a local shop and see if that fixes the problem. If issue continues just return them.

Another possibility, would be something to do with fuel. Are you using old or bad/low quality gas by chance? Next time you fill up, use premium and see how it does?

noahec2000

Discussion Starter · #16 · 22 d ago

ale5six1 said:
Being that the idle is good and it hesitates or misses only under hard load, AND b/c it stalled after warming up, I am heavily leaning towards distributor (I had the same exact problem before)
2nd idea would be something to do with fuel. Are you using old or bad/low quality gas maybe? Next time you fill up, use premium and see how it does?

We filled it up with 91 from shell and a different station that I usually go to to rule out that possibility

Waiting on that coil to hopefully rule out distributor, because everything about the distributor seems fine, like the shaft that spins the rotor doesn't really wobble at all so the bearing seems fine

After all this I'll follow up on what mossin said with the coolant temp sensor and fuel related problem, but the spark plugs seem fine so I don't know

Will post back on the new coil

Reactions: 1

msc

· #17 · 22 d ago

Another common distributor problem is the ignitor. Often when this goes bad the tach will give erratic readings.

Mike

noahec2000

Discussion Starter · #18 · 22 d ago

msc said:
Another common distributor problem is the ignitor. Often when this goes bad the tach will give erratic readings.

Mike

I'll go ahead and swap it out and see if it does the trick

noahec2000

Discussion Starter · #19 · 21 d ago

2

Look what I found when replacing the ICM...

Motor vehicle Automotive tire Engineering Personal protective equipment Auto part

Motor vehicle Automotive tire Automotive design Engineering Gas

I don't know how I missed this before, but that might as well be the issue (I'm hoping)

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mossin_90

· #20 · 21 d ago

Get the cables fixed up and check the inside terminals on the distributor cap and the rotor.

On a side note, those spark plugs looks like you are running lean. And I mean almost on fumes.
They should have a bit of a light brown at 1/3rd around the ceramic piece.

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