surging problem with 91 civic b16

[dj30224]

hey i have a 1991 honda civic with a b16a engine in it and my car idles fine for a couple of seconds then it starts to rev up and a down i changed the iacv but with one from a d16a6 manifold and its still doing it is it because i changed it from a d series manifold or could it be something else making it rev up and down any help would be highly appreciated

 

[BigNate]

B and D are diff. they have different voltage rates, and resistance. possibly causing that idle. replace it with a B one, and if thats still not it, check your wiring and Fast idle Thermo Valve if your car has one.. on the bottom of the TB. has two nipples on it for coolant flow.

 

[LS_VTEC]

Its your FITV. Remove the two coolant lines (get small vise grips to lock the return line closed so you dont spill coolant all over), Unbolt the valve assembly, then shake it. If you hear a rattling than the internal plunger is loose. Two philips head screws hold down a plate on the valve. remove that plate and the plunger should come right out. As for putting it back in correctly, you need to press it back in firmly and turn it clockwise to thread it back on. There should be a white plastic piece at the end of it. Using a flat head screwdriver, after it is actually threaded on, turn it more until moderately tight.Put it all back together and back onto the engine. Re-connect coolant lines and start it up. Your wild idle should be gone.

 

[LS_VTEC]

B and D are diff. they have different voltage rates, and resistance. possibly causing that idle. replace it with a B one, and if thats still not it, check your wiring and Fast idle Thermo Valve if your car has one.. on the bottom of the TB. has two nipples on it for coolant flow.

B and D series IACV's work exactly the same. They are also interchangeable. Valves are mechanical. They use mechanical energy to do work and send the ecu signals electronically. Like a speed sensor, for example.

 

[dj30224]

ok but like i said iv changed it to a good iacv and it still does it could it be my ect

 

[LS_VTEC]

Hard to say without diagnosing it in person but check your FITV. Could be an IM gasket as well, problems with the cooling system etc.

 

[dj30224]

i was told it could be the ect sensor (engine coollant sensor)

 

[dj30224]

well i changed the ect sensor but that didn't fix it.

 

[dj30224]

ok im not getting any help iv changed my iacv again still surging map sensor,also has been changed BUT HERES A QUESTION MY FUEL PUMP WASNT GETTING NO POWER SO IM STRAIGHT WIRING IT RIGHT NOW COULD THIS BE THE PROB CAUSE IT WASNT SURGING BEFORE I CHANGED THE FUEL PUMP

 

[p1s70np0w3r]

hook a vacuum gauge up to your car, i bet you got a vacuum leak...

 

[Uncle Buck]

well since you did all the work with checking sensers in the coolant area itself..... just simply check your coolant level.... hondas tend to surge when low on coolant and thus the rpm goes up and down

 

[haveasoda]

ok im not getting any help iv changed my iacv again still surging map sensor,also has been changed BUT HERES A QUESTION MY FUEL PUMP WASNT GETTING NO POWER SO IM STRAIGHT WIRING IT RIGHT NOW COULD THIS BE THE PROB CAUSE IT WASNT SURGING BEFORE I CHANGED THE FUEL PUMP

Have you got the surge fixed yet? What are the RPMs it is surging between? Mine surges only when they drop below 1300, then it will surge from 1000-2000, I have gotten sick of messing with it, tried a coolant change, new knock sensor as well as checked everything else that was suggested (TPS, O2 sensor, vaccum leak). I am taking my car in to the shop, I'll let you know what they tell me.

 

[BrokenRex]

please update when you get this sorted out. the D in my rex did this for about a month before it stopped starting up all together. not that it matters anymore, but i'd like to know why it was happening. i've heard other hondas do this when idling next to me at a stoplight, so it can't be all that uncommon.

 

[sleeper88]

I just bought a 90 hatch with a b16 and its doing the same thing. I'd like to know what the shop finds out too.

 

[goldgreen90ef]

Its your FITV.

fitz valve for the win!!!

 

[sleeper88]

My FITV was stuck opened. I bypassed it and closed it and it idles like it should. So FITV will never bother me again.

 

[Zorro]

Surging-Bad TPS?

hey i have a 1991 honda civic with a b16a engine in it and my car idles fine for a couple of seconds then it starts to rev up and a down i changed the iacv but with one from a d16a6 manifold and its still doing it is it because i changed it from a d series manifold or could it be something else making it rev up and down any help would be highly appreciated

I had that same problem. Then figured out it must be my throttle position sensor. I bought one on ebay ($17-free shipping), but waited a couple of weeks to install, after it stranded me at my son at a Burger King. At that point I wasn't getting anything at all. I just wouldn't start.

So, I've the TPS about a week, but had not yet bought the TB gasket. I would prefer to do it during the day. My wife was out of town on her way home and got in last night at 11pm. It's 4am now. It didn't take that long, I just had to work on her car, afterwards. Anyway, follow the instructions on this thread: https://hondaswap.com/general-tech-maintenance/how-remove-honda-throttle-position-sensor-tps-58326/ . I did the dremel method of making grooves on the "rivet" bolts. But because it was after midnight, I'm reusing them until tomorrow after work when I can get some new ones that I can use with a socket.

I got the TPS on, and it's idling at about 1800 now because I haven't calibrated it with a multitester. But, I think I'll just my wife sit inside and watch the tach and set it that way. But after about 6 weeks....NO SURGE!!!

Good luck!