It's James

Sorry for the length, but every detail is neccessary to understand the problem.

I have a 1990 Honda CRX si with a b16a2 engine transplant. It has an Si-R-II ECU, Place Racing external VTEC controller, and an APEXi S-AFC + some more mods.

I came back from college for winter break and my car has developed a strange problem. While I was away, my car recieved new axles and intermediate shaft, as well as battery relocation to the trunk. My car had been started up at least once every 1 1/2 weeks while i was away and did not act out of the ordinary.

Here is the problem:
I picked up my car on a friday night. The car drove fine except when i would give it more than 2/3 throttle. The car would vibrate like crazy (the whole dash would wickedly rattle as well as the driver's side door) until i let off the gas. Also, if i reved it past 3250-3500 rpms the car would also begin to rattle slightly.

The next day i drove it back to my garage to have it checked out. On the way there, If i maintained a certain speed, the rpms would spike sporadically. Ex. I would be going 40mph at in 4th gear, however the rpms would spike from a normal 3000 rpms every few seconds for a split second at a time. And, everytime it would spike, the car would slightly buck. By the time I had made it to my shop, any pressing on the gas would just result in the car dying, as opposed to idling like it normally should.

I figure that the rattling it was doing on friday night, was due to the rpms spiking very rapidly when i would give it 2/3 or more throttle. They spiked so quickly that instead of just making the car buck like it did the next morning, it caused the car to rattle violently because the spikes came in such quick succesion.

Now, what does this mean? That's the problem. I'm not quite sure. Neither is my mechanic. We think it is either a faulty MAP sensor, or distributor. My mechanic has been trying to figure out what it is the past week and has noticed that it only happens when it is hot, not when its cold. Therefore, he thinks it might be the distribtutor, even though the symptoms would lead one to believe it is the MAP sensor.

Before I left for school, when i was driving the car on a daily basis, the car had a similar problem which would occur. The problem was that every once and a while, (not every time, but quite often) when I gave the car full throttle, between 4000 and 5000 rpms, in either 3rd or 4th gear, the car just "fell on its face." I got no throttle response. Pressing the gas pedal gave no effect. Shifting to another gear did nothing either. I then had to turn the car off, and then back on again to regain throttle response.

No one could come up with answer for that problem either. And since it only happened occasionally, i for the most part ignorned it. However, now that i can't drive the car at all, I need an answer ASAP. Could you PLEASE tell me if you have any idea as to what this is. I would be very thankful.

Doodoo

Has it always run this way? Or just after the swap and goodies. You can try removing each add on, slowly returning it to stock.

Seems like a MAP problem. Try to clean it out, it may have some carbon build up blocking the signal just enough.

Could be a Ignition Coil going bad. Take your distributor cap off and do this:
Get a piece of wire. Ground one end to the chassis. Hold the other end NEAR your coil NOT IN IT. Have some one crank the car while you watch the spark arc across the wire. It should be pretty bright. And don't touch anything else or you may shock yourself. My mechanic taught me this one.

Good Luck dude.

Perfectionist

The tach bouncing is sometimes a sign of a failing ignitor module.

litlekikr

I had this exact same thing happen in my '87 prelude. It's carbd. and doesn't use the computer as much as the b16 would but what happened w/ mine is the bolt that holds the cam gear to the cam came out. It was weird but it did the EXACT same thing as what your describing RPM spikes, no power stuttering then dying. If you have cam gears double check that the bolts are tight. I know it sounds stupid but it happens. I've only heard of it happeneing twice and both times it was on an older car, my 87 lude and a friends 86 civic.
Also, the rattling could be caused by your axle. I put a new axle in my vw rabbit and it shook like hell so i replaced it and it fixed the problem. Maybe you got a bad one?
hope that helps.

low-tech assassin

check your timing.....

slowpokesi

okay heres a shot,
on my b16a when my distributor was on the fritz it would only rev to like 3500

i would suggest replacing your plugs, plug wires and distributor cap do a lil tune up, also run some techron fuel injection cleaner through it, and then lastly check the mounts to make sure tehy are all secure that might explane some of the vibrations, also check to make sure that none of your grounds are touching anything, the car could be grounding out.

Spaceballsthelunchbox

It is absolutely, positively your ignitor.
i have had them fail in three different ways.
Once it completely died, period.
Another time it would only let the engine rev to 2000 RPM and then hell would break loose.
An another time it failed intermitently, It would work fine for a few minutes then act up.
Every time the tach did all kind of crazy things, the reason is the the tach gets its signal directly from the ignitor.
So go get one from Honda, I have had bad luck with the aftermarket ignitors.

xjoe

i had the same sort of problem as well, but it was due to ignorance, one of my spark plug wires on the dist was unplugged halfway

CRX-RX

If the motors RPM's are actually spiking, not just the tachs, and all the shaking is happening while the car is driving in gear, and it happened before, you may want to take a look at the clutch.

ThatRicerDaniel

man thats fu**ed .. wish i could help you.

JALOP B16

it sounds like your coil is shot.
when it does it again try hiting the dis with you hand if it goes away for a sec its your coil.

XEF-9X

hahahah thats ****** rad!! that was a good laugh. talk about home made mechanics!!

743

something similar happened to my ls/vtec. i replaced tons of **** and it still never worked. so i took the engine apart to find that a quarter inch peice of my total seal ring broke off and demolished one of my je forged pistons. hopefully your situation isnt this serious. i rebuilt it with oem rings and replaced the piston and it ran perfect.

spankaveli

check and make sure the plug wires are securely connected to the distributor

oh, and yeah, more'n likely the ignitor

It's James

thanks for all of the responses guys. I'll let you know what works.

JALOP B16

hey that **** worked for me, I hit it it stoped sputtering for like a min. So I was like its the coil.......

sgT

SiR and SiR2 ecus are the same.

remember that those do not designate generations, only trim levels that were
available from 90+