Engine dies , erratic idle - pic of possible problem

[nope-mx3]

I did the HEI module mod about 1 week ago, and now it runs good, until I press the clutch, then it just idles down and dies (not like when the ignitor module was bad and it died directly, it runs all the way down to 0 rpm, if I blip the gas, it goes up).

Also when it just sits in neutral idling it varies in rpm.
Seems to do this when I let go of the gas aswell in 2nd and 3rd etc.

I`m thinking maybe a hole in the plastic after the VAF, but I`m not sure.

nope-mx3

[PATDIESEL]

could easily be that or you might have messed up something when you did the Hei module. Although I'm not usre what sine replacing it shouldn't have anything to do with the idle.

[nope-mx3]

I`ve had this problem before too, but not this bad.

I dont think it`s due to the HEI module, but of course, I`m not sure.

nope-mx3

[Nallboy]

I`m thinking maybe a hole in the plastic after the VAF, but I`m not sure

Look that accordion-like piece over. I had a crack in mine before I decided to swap. It happens alot, actually. If that's it, I have a pretty much brand new one (only used it for a month) sitting in my shed.

[nope-mx3]

Hmm, I just remembered... when we did the HEI mod, the thing you hook the 3 pin wire onto on the disty, it cracked on the bottom, so it`s a bit loose... easy to wiggle up and down....

Heard someone say a cracked disty cap could create strange problems.



I marked it on the 6 pin, but it`s on the 3-pin, opposite side (on the bottom below the plug)

nope-mx3

[jschrauwen]

Also when it just sits in neutral idling it varies in rpm.
Seems to do this when I let go of the gas aswell in 2nd and 3rd etc.
I`m thinking maybe a hole in the plastic after the VAF, but I`m not sure.
nope-mx3

Nope, if you're still using the accordian type intake tubing between the TB and VAF, then if there is any leak in between there than you could possibly encounter a fluctuating idle. Mixed signals getting to the ECU in that it thinks that the vaccum is lower and therefore lessens the amount of gas to use. It could turn into a progressive situation to a point where it gradually idles down to zero. Coincidentally, a misadjusted TPS could also lead to "idle hunting" as well as incorrect water thermosensor info being sent to the ECU.
If local vehicle regulations permit, perhaps a CAI may be a way to get around the possible crack in the intake flex tube. They're actually very very cheap on ebay and you'll never have to worry about possible degredation of the flex tube again.

[jschrauwen]

Hmm, I just remembered... when we did the HEI mod, the thing you hook the 3 pin wire onto on the disty, it cracked on the bottom, so it`s a bit loose... easy to wiggle up and down....
Heard someone say a cracked disty cap could create strange problems.

I marked it on the 6 pin, but it`s on the 3-pin, opposite side (on the bottom below the plug)nope-mx3

Nope, confirm you're running a ZE?

[DavidOS]

check you grounds as well??

[J0HN_R1]

... Mixed signals getting to the ECU in that it thinks that the vaccum is lower and therefore lessens the amount of gas to use. It could turn into a progressive situation to a point where it gradually idles down to zero...

Although I agree with your next sentence (about the TPS) after the quote, I dont agree with this one.

A hole in your stock intake tube (I have both!) will cause the engine to idle up, not down to the point of stalling. The hole creates a vauum leak, like you said. But the leak causes the VAF to tell the ECU to add more fuel/air due to low pressure, thus 'idling up' to increase airflow and vacuum... It goes up & down because it's saying "OK, more, ok, good, oh-oh more again, ok, good..." except REALLY fast...

[nope-mx3]

I`m running a stock GS.

The problem started really really bad after the HEI mod (and after the accident in the pic).

Before it was probably the bad ignition module in the disty acting up.

It has never been this bad before.
It can be running very nice at idle (around 6-700 rpm), in neutral.
Then, if I just barely blip the throttle, it starts to increase to 2000, then down to 3-400, and up to 2000 etc.

it usually only when I`m driving it drops so low it dies when the clutch is pushed in.

nope-mx3

[J0HN_R1]

I'm having a similar problem, in that my engine wont come down from cold-start/high-idle easily. I can get it to come down, but it wont stay down all the time... This problem has only occured since I had "your problem" of erratic idle. Not knowing where to start, I played with the air-idle screw & the throttle stop-screw were the cable attaches to the TB... The I found out it was caused by the split in my stock intake tube. Quickly 'bandaided' with some 100mph tape, my idle evened out but was high. I haven't been able to TOTALLY cure it, I played with them multiple times with limited success. I can get it to were I want it, but shortly there after it gradually climbs to the 1500rpm area (+/-) and wont come back down with out blipping the throttle alot and shutting all the accesories off to limit parasitic-loss from drive belts...

That said, yes, I have had electrical problems (alternator pooched, got a new/used one) lately probably because my battery is crap! And its a Honda battery, go figure... It was i the car when I bought it. I got a near brand-new Interstate today, gonna chuck it in and hope for the best... Now I just need to search for that dang PIN config and short 2 out to reset my ECU... Hope I dont FUBAR it... LOL

* have you tried a new dist. cap yet...? have you put it back to stock?

John

[jschrauwen]

Saw a neat little trick at the RX Ottawa meet. To determine if you have a possible crack in your intake tubing or a vaccum leak anywhere for that matter. While the car is running, take a plain water bottle sprayer that will give a very atomized spray. Spray in the possible vicinities of the suspected leak and the idle should die down or lower. Narrow your spray pattern to zero in on suspected area. Conversely, instead of using a spray type water bottle, use a can of (lighter refill fluid) butane. Again, spray at all the various portions of the intake tube (ribbing) and if the rpm's pick up you know you have a leak. Use the spray to zero in on the suspected area.