Thee_Antic

Alright..just got a TON done on my car. Intake manifold, cleaned EVERYthing..throttle body, fiacv, the thingy attached to the manifold, head, put a gsr oil pump on, moroso oil pan..anyways. A lott of **** got done.

Everything is put together correctly, checked twice etc. etc.

Primed the engine beforehand because of the oil pump..

Now heres where the "fun" **** starts..I go to start my baby..it cranks, and "technically" runs for .5-1 second then dies. My guestimate is that its around 1k rpm?

Well when I crank it with throttle, it revs up..I assume if I keep giving it throttle it would stay running...but Im a *****, so I let off the throttle and it dies right away.

The stupid PO was running an OBD2 throttle body gasket..which probably had all sorts of vaccumm leaks going on..I now have the correct OBD1 gasket..but maybe he tweaked the car to run with a vaccumm leak?

I'm guessing I just need to adjust the idle..but I have no idea how..I'll be researching that now.

Also its possible, yet unlikely, that I got the sensors on the fiacv, tps and that other one mixed up..would this cause the problem?

Thanks for the help.

Thee_Antic

Theres also a sensor right below the middle of the intake manifold that I have no idea where the plug is..or if there ever was one..

Not sure if that has anything to do with my problem but figured I would let yall know

Former User

1) Information about car and engine
2) CEL codes
3) Pictures of said connector and colors of the wires

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Provide all pertinent information about your car and engine:

Thee_Antic

Oh ****, my bad.

1994 Del sol, fully built all motor b16a.

No engine codes..but for all I know he just unplugged the light..



Its #2, knock sensor. I did a search and a lot of people leave them unplugged...so nevermind lol.

Thee_Antic

The idle air screw is all the way closed, and so is the throttle plate.

Not sure if thats normal or not.

frankenghia

idle screw all the way in is not correct. throttle plate should look pretty much closed if not appear to be completely closed. Back the idle screw out and try to start it. Does the cel come on for a few seconds and then turn off when the key is turned to the on position?

Thee_Antic

Hmm..still nothing.

Former User

Someone may have messed with the throttle stop screw, which should never be done. If so, the throttle plate may now be fully closed when the throttle pedal is not pushed down, rather than open about 9%, which is normal.

joeshmo

It seems odd that it would be open 9% at idle, as opposed to just allowing the IACV to handle all of the idle air (as one would assume it is there for.) So I am to understand that the IACV is just a supplement to the 9%?

Former User

Not sure why you would assume this^.

Correct.

joeshmo

I would assume that considering the name (IDLE AIR control valve.) One would think they would say Idle air supplement valve or something like that. But now it makes sense why an engine wouldn't die if you hold your finger over the IACV hole. Sorry for the slightly off topic post, I was just curious!

Former User

Yeah, most air for idle comes past the throttle plate. The IACV is primarily for fine tuning purposes. So "control" means fine tuning rather than "complete idle air control".

Thee_Antic

Still no luck, Im going to look up how to adjust the throttle plate because its obvious the PO screwed around with it.

I'm pretty sure I flooded the engine, going WOT while yelling at my car to just "****ing start!" probably wasn't the best idea..

Yeah, plugs are soaked..oh well.

Former User

If the PO tampered with the throttle stop screw, consider replacing the throttle body because re-adjusting the stop screw can be very tricky.

Thee_Antic

A couple hours messing with a screw > $250 throttle body

I can't imagine it being all that impossible..

Former User

You almost surely could pick up a used TB for much less than $250. But anyway, good luck.

Thee_Antic

Got it started, turned out to be fouled plugs.

Took a little time to adjust everything on the throttle body, got the idle to 1k happily.

Only problem being that after taking it for a test drive, idle went down to 500 and started bouncing. Up and down 500-1000k. Not sure what it could be, I cleaned everything and there is a difference when I unplug the Iacv (I think that means its good)..

Opinions?

joeshmo

I had a leak in my IACV gasket, causing a surging idle from 1-2k rpm. Did you reset the ECU yet? Engine has to re-learn idle.

Thee_Antic

Hehe, woops.

I'll reset it tomorrow when I switch out to my ngk iridiums and do a little tuning.

One thing that I did notice, when the this was happening the walbro fuel pump was kind of doing the same thing. It slowed down with the engine and vice versa. Not sure if it has anything to do with it..

If that doesn't fix it you'll be hearing back from me lol

joeshmo

Make sure those iridiums are gapped properly. The ones in my engine when I bought it, weren't (they were NGK iridiums.) You need a special gapper tool that won't damage the electrode. I don't really know if the ECU would be able to cause a fluctuating idle like that, but it could be the IACV opening and closing all the way, trying to find an idle point which would be controlled by the ECU (I think.) An ECU reset wouldn't hurt.