1995 accord idle surge.
 

Ok so first off, my 97 accord got stolen right after I did another head gasket on it and replaced the smaller timing belt. Awesome times.

Replaced it with a 95 accord I picked up for 300 bux. Bought it with a known issue of idle surge. According to previous owner it's had new head gasket (I can see the tab of what appears to be new hg) head machined, new timing belt, and new IAC.

Car came with a new throttle position sensor since it still had the surge issue. I've installed that, tightened the fitv, and bled the cooling system, surge persists.

Since it doesn't have odb2 my code reader is useless, but we did jump the connector and it gave us code 4, crank position sensor. I got no problem with replacing that, but I doubt that is the cause of the surging idle.

So whats left? I've visually looked and listened for vacuum leaks haven't found any. When it is surging I can hear what sounds like a flap getting slammed opened or closed in the airbox or air tube somewhere. (not sure if thats relevant) I've seen posts indicating that it could be a map sensor, but thought I'd seek advice here before I just go changing another part.

I gotta get this car up and going for the ol lady cause we're sharing my truck right now, and we really need the fuel mileage of the honduh, and I gotta get her the hell outta my truck.

Thanks in advance!

Does the idle surge at idle? You can pull of the snorkel from the throttle body and use your finger to cover the lower port that goes to the FITV. If the idle stabilizes, then your FITV is likely the issue.

A code 4 can be from the crank sensor, the wiring, or possible the ECU. The crank position sensor is inside the distributor on the 95 accord, so check the wiring inside the distributor and the electrical connector before replacing it.

I'm with PA - rarely do the TPS or MAP sensors fail on these even though many seem to replace them all the time :shrug:

Be sure the coolant is properly bleed of air, clean the FITV and the IACV....be sure the coolant hoses to them are clean and allowing coolant to flow. Then since there is strong evidence work has been done to the head, you really need to check for any vac leaks....doing a HG replacement many will get the intake gasket wrong or the injector seals...then there are other sources...other gaskets, vac lines, ect.

Rock on! Thanks guys! I'll see if I can get a mini torch over here and try to hunt down a vacuum leak.

We've had the throttle body on and off about 4 times now, the kids are getting good at it. I'll check the distributor wiring for the crank sensor and worst case replace the sensor if I can't find any bad wiring.

Also, if I physically close the throttle linkage, (close it further than the spring does) it stops surging. I'm not sure how to factor that one in...

Finally got to get back on it today... Er, well got a new battery in it so we can start it on demand... We've been waiting on title work and all to get it tagged before I put any more work into it...

Still surges, but today I noticed that it seems like there is alot (ALOT) of exhaust pressure... I'm talking you can stand 4' off the back of the car and it's blasting your pants.

Surge is between 1k-1250 and it does it in gear, once you get going it's ok, but say you go to try to hold a steady pace, and the surge is back... (I think, feels that way on surface streets, not hi-way tested yet)

Still throwing the crank position sensor code, out of money for now so we'll be getting that (or checking the wires this weekend) next payday. Hope to get my brother over tomorrow to help check for vac leaks... Ugh. I don't wanna tear this thing down...

Question: With the previous owner having had the head gasket re-done and the timing belt... Is it possible, that they got the timing slightly off (like a 1 tick)?

The only other thing I can think of is I've seen some having the same issues with a intake manifold gasket issue...

Thoughts?

Ninja edit: compression is 180 on cyls 1-3 and 190-ish on cyl 4

You can always check the mechanical timing. You'd have remove the valve cover, get the crank to TDC, then see if the cam sprockets are at TDC.

Did you ever try this suggestion from my earlier post?

Crap. I think I did but I don't remember the result... I'll re-do and report back.

I do know I did remove the the fiv and tightened it back up with no change. And it surges regardless the temp.

Put new battery in yesterday and it seems it's harder to start and running a bit rougher...

won't really idle, just surges. I'll try to get video... It used to be I could force the butterfly closed and it would settle, but it won't do even that now.

Well, 1 tooth off will let the engine idle and idle smooth (if it actually starts), but it won't really let you rev the engine (it struggles). So if yours will free rev, then it's not a tooth off. I just went thru that in October on my 99 Accord that I had just bought. On it, the harmonic balancer had come loose, and the key walked out of the lower pulley about 1 tooth. It would run, but it was a dog. Fixed it, and it runs sweet.

Usually a vacuum leak is pretty steady and wouldn't raise and fall. To me that sounds more like an IAC (Idle Air Control) valve. I'm not sure if your engine has 1 or not though (it might be combined with the FITV).
Another thought would be that you've plugged the IAC plug into the TPS, and vise versa. I think I've read that somewhere in this forum that it can happen, and you have had the head and intake off. Maybe??

Went out today and tried that. No change. See videos... er, well I didn't video doing that test, but they show how it behaves.

See I have almost the exact opposite issue. engine will rev just fine, but will not hold idle or steady throttle input.

I can put closing pressure on the butterfly and the idle settles down and idles normal. I'm going to be checking the adjustment on the new tps and make sure it's correct, but I don't see that causing this issue as it was behaving the same before the tps was installed. I'm also starting to suspect the IAC, but a new one was put on before I bought the car, I suppose it could be a bad one but, I dunno.

anyhow here's the vids...
https://youtu.be/ABMZHSZwUUQ

https://youtu.be/ieM-o4pFoO0

Your issue is not the IAC if a new one was installed. Plus you can see the bouncing rpm showing the IAC trying to adjust.

What are the wire colors going to the MAP sensor and the wire colors to the throttle position sensor? The TPS should have grn/blu, red/blk, and yel/blu. The MAP has yel/wht, grn/wht, and wht, yel. Those connectors are identical and it is possible to switch them.

Disconnect the throttle cable from the throttle body and the cruse control cable. It is possible that a bound cable or incorrect installation is allowing the throttle plate to stay open.

Make sure you aligned the TPS with the slot when you installed it. The TPS is slotted, so there is an adjustment where you want the output voltage to be 0.45V and that is the middle wire (red/blk). You would need to back-probe the tps sensor connector and use a volt meter.

This is kinda what I've been wondering because if I turn the butterfly by the wheel, one of the cables comes off the wheel...

I'll check the wire colors and get a pic momentarily.

https://scontent-dft4-2.xx.fbcdn.net...a9&oe=5911C390

https://scontent-dft4-2.xx.fbcdn.net...ba&oe=593E95F3

https://scontent-dft4-2.xx.fbcdn.net...63&oe=593FFDBC

disconnected the cables going to the butterfly wheel. No change.

video link below. I plug the hole in the 10-11 o'clock area of the throttle body and the surge quits, but it almost kills the engine. plugging the hole at the 7-8 o'clock area makes no difference.
https://youtu.be/UBovwGf4Puk

If the camshaft timing is off 1 tooth, it really depends on which way it's off. One way it idles fine but won't rev. The other direction it revs fine but won't idle. Wish I could remember for sure which way is which, but I think if the cam is retarded it'll rev just fine.

Yeah the next steps are to put the intake tube back on, hit the intake with some carb cleaner and see if it's sucking air, if not, then we'll be tearing down to check the gears....

I'd probably double check the timing anyway. When I did the harmonic balancer replacement on my 99, I found that the lower gear had moved to the left 1 tooth. The rest of the marks lined up. That was all it took to keep it from running correctly.
It's a pain in the butt to dig in that deep, but for peace of mind it's worth the extra work.
I know I slept better after replacing the belts once I found the problem. In my case the PO thought it needed an engine.:eek:

When you mention the harmonic balancer that jogged my memory...

If you don't find anything, you can check whether the outer pulley has slipped against it's hub. The pulley is attached to it's hub through a layer of hard rubber, which can get oily or rot or shrink, allowing the outer part of the pulley to move a bit.

The actual timing sprocket on the crankshaft has a timing mark that you can check.

Another check is to remove the spark plugs & stick something down onto the piston. Rotate the engine around TDC and verify that the piston is actually coming to the uppermost position when the crankshaft timing mark is aligned. This is less accurate than the timing mark on the sprocket, but it's a lot easier to do.

I asked about this in an earlier post. Did you try this?

Make sure you aligned the TPS with the slot when you installed it. The TPS is slotted, so there is an adjustment where you want the output voltage to be 0.45V and that is the middle wire (red/blk). You would need to back-probe the tps sensor connector and use a volt meter.

I have not back probed this yet, but my brother (a genuine tech) aligned the tps when we installed it... but that is first on the list when I get to get back at it... (I forgot to mention it before putting the tube back on and spraying the manifold) It was aligned to where the old one was so I want to rule that out before tearing into the side of the motor...

luckily enough having had to tear into the side of the motor of the accord that got stolen multiple times, we're almost old hats at it now... lol I can tell my 15 and 17 year olds to go tear it down to the timing belt and 45 min later, they've got it done... They'll like this one better I'm sure as all the plastics on this one looks nice, the ones on the old one were chewed and crunchy...

Also, make sure G101 is attached (see pic). You may want to unbolt it and clean the eyelet and bolt with a wire brush or sand paper.

EDIT: It is on the driver's side of the upper intake manifold.

https://www.hondaaccordforum.com/for...-g101-6236.jpg

HELP.

Where the hell is the damn crank position sensor? I re-aligned the timing. surge remained, not as big a surge it seemed, but still remained. still only getting crank position sensor CEL. Took back apart, can't find it at the crank. Can't find it in the distributor.

I'm about to fill this thing with a bunch of .223 holes.

Plugs look like it's running rich. We had me, pops, and little brother, out there working on it today and we're beating our heads against the wall.

PAhonda What is that thing in the diagram?

Its a ground wire

Ok I'll check that tomorrow. (the ground) While we were working on it, it blew the upper radiator hose off... Going to also pull the t-stat tomorrow...

Still trying to find the crank sensor. It's still throwing a code for it. I know it's not behind the crank pulley... I pulled all that crap back apart thinking it was but it wasn't. Took the distributor cap off cause someone had suggested it was there, but it didn't jump out at me there either...

On a 95 the sensor is inside the dist. Doubt you find the part by its self, most of the time the whole dist is replaced. Of course you want to be sure it is bad by testing it out.

It's consistently throwing the code for the crank sensor... I've checked the wiring (will again today when I get back out there) and it seems fine, no nicks or broken wires.

damn distributor is 180bux.... I'll have to see if I can pull one from a junk yard or something...

If the wires are good and the resistance is within spec then more than likely the sensor is done.

At a reach, you could pull the cap. rotor and that "dust shield" under the cap and look to see if there is "rust dust" (tech term there) or something like oil under there. Of so you could try to clean it with electrical cleaner - be sure no power is running through there. The sensor is like a "hall effect" type of thing so if there is dirt and that in there it could throw off the readings giving you the code.

Pretty sure this will not solve the "surge" issue.

So you think the crank sensor wouldn't be causing this?

Crap. I'm outta ideas. I'm getting ever closer to dragging it to some land and using it for target practice...

You have a ton of stuff going on at once. I think you should take a step back and check some basics. Please report back your findings.

1. Do a compression test on all four cylinders. Pull the fuel pump fuse. Make sure you push the gas pedal to the floor.

2. Inspect the spark plugs when doing this test.

3. You blew off a radiator hose in a previous post. If you brother has a chemical test for a blown head gasket, you should test for exhaust gas coming through the radiator.

Compression is 180 across 3 closer to 190 on the last.
I attempted to find the whole "relearn" for the trottle body and can't find the fuses everyone says to pull. there was no fuse labeled as the directions stated... I'll see if I can get out there again.

plugs look like it's running rich. they are the 4 lead plugs which I'm not a huge fan of, but they show dark.

I haven't got the tester, have the liquid tho, but on the previous accord that came back ok and I still had a blown head gasket.I'm thinking it wasn't on securely which is why it popped off. I don't have any other HG symptoms I've noticed. Will check again.

https://scontent-dft4-2.xx.fbcdn.net...dd&oe=59322F4F

https://scontent-dft4-2.xx.fbcdn.net...ea&oe=59389999

Got the distributor all apart. Shaft is a bit rusty... going to clean it up a bit and throw it back in and see if there is any difference... Considering going to a junk yard to try to find a replacement. But dunno I'm still no closer to having a direction to go on this damn thing. Also going to go look at a 600 stratus later today. Gotta have a 2nd car going, my poor truck is eating fuel.

Well this honduh's saga has come to an end...

I sold it off today for 400 more than I paid for it, running worse than it was when I got it... lol

They got the added bonus of some 15" alloys to go with it. lol

Currently trying to get either a toyota avalon or a stratus. Whichever comes up with the title first... lol