mike1986fyrbird

Alright.
Finnally got my new engine in and its having the same problem the old engine was having.
Its a surging/rough idle ONLY when the est (tan wire) is connected.
It idles fine and doesnt surge or jump/fall rpms when the ESt is disconnected.
Base timing is set to 8*btdc.
New parts:
Everything from the valve covers down (minus sensors)
IAC valve
PCV
TPS Volts are fine and within spec.
New cap, rotor, wires, and ignition coil.
When the car is idling with the est connected it will show about 20* at idle, but it jumps around quite a bit, like 5 degrees and this is when it seems to surge and run rough.
It also surges when cruising down the road.

Any ideas?
Thanks

Nixon1

It's odd that the motor doesn't like the electronic advance.... How is your fuel pressure?

mike1986fyrbird

Fuel pressure is fine and is set at around 43psi at idle with vacuume disconnected.
The plugs read fine as they are all a light tan color.

kirk158

my thoughts are distributor lose move crank with socket while watching rotor do both move at sametime no slop..... and do you have a spare ecm to swap out

mike1986fyrbird

No spare ecm.
There is no slop on the dist and the gear is new.

Nixon1

How does it drive running on just base timing? Any missing, backfiring, loading up? Have you put it under load to see how it responds?

mike1986fyrbird

I havn't driven it around with just base timing as its raining and I havn't put the hood back on the car yet.

I connected a vacuum gauge up to the intake. This is with the EST connected.
It reads about 18 and goes to 16 when the engine surges(within idle spec on the gauge).
When its in gear it and the idle surges it goes between 12-16(within gear spec on the gauge). I'm asuming the vary in the vacuum is because of the drop in the idle.
Havn't checked it witht he EST disconected - is this som,ething I should check?

Nixon1

Shouldnt make a difference....vacuum is vacuum. Your vacuum sounds okay anyways....

Might try disconnecting the IAC valve, and reconnecting the EST and see what happens?

Also how is your EGR valve? I cant help but wonder if the thing is stuck in closed loop.

mike1986fyrbird

EGR valve is deleted. (Holley stealth ram intake) and is also deleted in the chip.
The car does go from closeed - open look. I verified this by jumping the 2 connections on the ALDL connector and letting the car run. It flashes fast then starts to flash slow when it changes loop.
I already tried disconnecting the IAC and having the EST plugged in and it made no difference.
I'm stumped.

Nixon1

So am I man... All I can say is...when it dries up, drive it and report back of any strange symptoms, aside from the expected sluggishness from little advance.

kirk158

thoughts are check the egr with engine running pull or push the egr valve in/ up and see if motor stumbles ...thats good ..also icm has control over situation from what I have read here. i have a rubber hase 1/2 " that I use to find vacum leaks like at the brake booster

Nixon1

Scroll up...already been covered

mike1986fyrbird

Ok, So I tried out a new ignition module and it does the same thing.
After I turned it off I took off the intake piping. I opened the throttle blades by hand (engine off) and smoke started coming out that smelt like gasoline.

Any ideas?
Engine specs:
Holley Stealth Ram Intake
Comp xe268 cam with 114 LSA
24 LB injectors
43psi Fuel pressure with the line off.
I changed the injector constants in the chip from 22lb to 24lb for the LT1 injectors.

Nixon1

Smoke coming out....of an EFI, multiport manifold? Is she running rich enough that she's puddling fuel in the lower manifold? Uhhhm.....well you have no EGR...is your PCV system closed and properly routed back into the intake? She doesn't have any blowby does she?

mike1986fyrbird

I set timing to 0* base with the EST disconnected. I plugged the EST back in and it ran fine with slight lope (the cam? comp xe-268)
Maybe the timing mark is off? The timing cover is MR.Gasket along with their timing mark for a 7" balancer.

Any way to check this without a piston stop tool?

mike1986fyrbird

I have the PCV valve on the drivers side valve cover that connects under the plennum. The drivers side has a breather that connects to the throttle body liek the stock configuration.

The thing is - it doesnt seem to be running rich because all of the plugs look like a nice tan color.

Nixon1

Do you have the factory harmonic balancer, with the rubber seal? These are known to 'slip' and the outside can actually spin on the rubber, causing an out-of-time reading. My old 91 V6 timing reading was off the chart, I suspected this was the reason but never fixed it.

I'd suggest look into purchasing a new harmonic balancer.. A lot of companies make solid, 1-piece balancers that are great...I bought one for my 302 and it's a nice piece.

mike1986fyrbird

I checked the harmonic balancer before I put it on the new engine. The timing mark was lined up perfect with the keyway.

EDIT - Also, when I had the car set at 8*btdc it would take about 3 or so seconds to start and it seems beter now. Hmm?

Nixon1

As far as running rich, you'd be surprised. The number one cause for a surging problem, is excessive fuel pressure. My old motor ran rich too, and the plugs always came out fine....but it was still running very rich, and my surge disappeared when I reduced fuel pressure. Try setting time like it was before, 8 degrees of base advance.....then reduce your fuel pressure by around 5 psi, slowly.... Rev it up a few times, and see if it clears out and stabalizes... It may take a little while to take effect, it may not. All depends on how loaded up it was

Nixon1

Slow cranking comes with advanced timing. Cars always fire up faster with very little advance...that's why ignition boxes for race cars have a starter retard

Mike...call me crazy, but I'm gonna put my money on youre running rich.

mike1986fyrbird

Plugs look ok, but I still may be running rich I guess. But why? hmm?
Upon further investigation, the computer likes to switch back and forth between closed and open loop. I am running a 160tstat, maybe I'll have to search the boards and see what I need to adjust in the prom to fix that.

Nixon1

Just FYI, 160 is a little too cold for computer controlled cars. That may be causing your open/closed loop problem. Id suggest a 180.

mike1986fyrbird

I just tried lowering fuel pressure and it didnt make a difference. Hmm

mike1986fyrbird

Alright just checked my fuel pressure again.
Key one (prime) goes to 40+ psi and immediatly drops and doesnt hold pressure like it should.

I unhooked the return line and primed it. It seems to come out of there as fast as it would go in the feed line.
Any ideas?
thanks

Nixon1

Well the return cycles excess fuel back...so it pouring out is no surprise. Look for fuel line leaks, youre obviously having a major fuel pressure loss somewhere. The NORMAL culprit for this is a broken or stuck injector which could be flooding the intake port on shutdown, possibly causing the gasoline smell youre describing

mike1986fyrbird

Hmm.. This is messed. I checked it again and it was fine and it didnt loose any pressure.
I tried it a few times and it held pressure.
Kind of weird.
I guess i'm going to have to buy a cable to datalog.

Nixon1

I'm not too familiar with the makeup of the fuel system but maybe there's some kind of check valve on the return-side of the system that's not holding and allowing all of the fuel to drain back to the tank. But if it's still holding normal pressure when youre running it, it shouldnt really affect driveability I wouldnt imagine... Sure it wasnt just leaking out your gauge anywhere?

I'm kind of at a loss as to what to tell you at this point, man. Without really digging into it and being able to get my hands on it, I just don't know...

kirk158

Any way to check this without a piston stop tool? [/B][/QUOTE]

bring to tdc insert screw driver see if piston is up all the way up or plug hole with rag will blow out when near top .......check mark

1FSTZ28

Surging problems/Bad idle problems are some common problems that the HSR causes. I have been having the same problem every since i installed the HSR, i also had about 5 SES codes so i started replacing sensors. I ended up replacing the IAC, MAF, MAF Burn-off relay, MAF Sensor relay, Fuel Pump Relay, CTS, etc.. Still throwing a code 33. I have a custom ordered chip on its way and i will be driving to Ohio to get a CUSTOM dyno tune/chip from the same person i am ordering the chip from. I guess my whole point of this is if you dont have a custom chip from what everybody has said you need a custom chip. Just my 2cents

mike1986fyrbird

It did the same thing on my last engine with the TPI set-up. I thought it was the fuel injectors and I replaced them on my currect set up and it still does it.

1FSTZ28

I would recommend trying to get a custom chip/tune to see if that helps. That is what i am doing.

Johnny Blaze

iTrader: (15)

Sounds very familier. I have been having similer problems with mine after the stealth ram swap.

Got a stumble problem, can't figure out.

Had a chip burned from a guy here.


1FSTZ28, can you give me the contact info of the place you are taking your car to in Ohio for the tuning? Feel free to pm it to me.

Rob Wade

You may have a tear in the diaphram in your fuel press. regulator. The vacuum will suck fuel into the plenum. Also messes up the fuel pressure and your now sending fuel down the runners that shouldn't be there. I would install a new diaphram. I'm assuming also that you have already checked for vacuum leaks @ the intake right?

Brianbajnuth

Was this problem ever fixed? What was the solution? I have the same problem

86LG4Bird

iTrader: (1)

whelp....10 year old thread........chances are he won't see this
But.......I had the identical problem a couple of years ago. The ECM was bad.

CashMunson

iTrader: (1)

I had the same problem, my distributor was off. The first thing I would do is pull #1 plug, bump the motor until it blows your thumb out of the hole, remove the distributor cap and verify that you are at tdc with the rotor. If that's not it, then it could be the ecm or prom.

Brianbajnuth

My engine runs perfect with the est wire disconnected. The engine wouldn't run properly with or with out the wire in or out if the distributor is off?