New stroker idling rough - running rich?

[bulfo4]

We put a 4.6L stroker into our 1996 XJ and it drives, but it feels like it should be driving better. Getting it running was a challenge (previous thread: http://www.jeepstrokers.com/forum/viewt ... =15&t=3527). Additionally, we swapped to the 99+ intake, headers, and 24lb mustang injectors, but we didn't put on a bigger throttle-body YET, nor did we add map adjuster yet (sounds strange, but wanted to see how it ran before and after the 63mm tb)

Here's what it's doing:
- low vacuum - like 12" instead of 18-22"
- rough idle, but runs well above idle
- slight over-heating
- white smoke puffing out of the valve cover

Things we've tried:
- new IAC, MAP, O2 Upstream, O2 Downstream, new fuel pump (good pressure to the rail), new temp sensor on the back of the head, new distributor and cam sensor, new crank sensor, properly indexed (and quadruple checked), new ECM (which has been reset each time we've changed things).
- checked for vacuum leaks a number of times by shooting starting fluid on any hoses / fittings with no result. To see what we should be looking for, we shot a little into the air intake and throttle body which instead of revving it up more, choked it and killed it.
- took it to the dealer and they saw the same thing and recommended swapping the 24lb injectors back to the stock ones
- swapped injectors back to stock and it runs better (less smoke, a little better vacuum, a little smoother idle, but still rough).

- From our actron code reader:
No Codes
Abslt TPS - 15.3
RPM 762
Clac Load 6.7
Map "HG - 12.1
Coolant - 196
IAT - 196
IGN Advance - 17.0
ST FTRM1 - 0.8
LT FTRM1 - 0.0
MPH - 0
02S11 - 0.360
ST FTRM1 - 0.0
02s12 - 0.700

Next:
- Seems like maybe the bigger TB and the bigger injectors probably ought to go hand in hand, so we have a new TB on order, as well as a MAP adjuster on its way too for fine tuning.

Questions:
- Anything else we should be looking at to get the air/fuel mix better?
- What types of numbers should we be getting from the code reader?

Been working a lot so I haven't had much time to work on the Jeep. Hope to do more after the weekend.

Thanks!
Tom

[bulfo4]

Update

New 63mm Throttle body got here and I put that on and it seems to run a little bit smoother. There's almost no smoke coming from the valve cover. The vacuum pressure is up to about 12 instead of 9-10. Still is pretty rough though. I haven't had time to fully wire in the MAP adjuster yet.

Anyone have any ideas or suggestions? Maybe some numbers from a code reader we should be aiming for?

Thanks,
Tom

[gmakra]

Look at yiur IAT intake air temp something is wrong with that sensor, location wiring something cause if your reading 196 your in Hades

[SilverXJ]

Here's what it's doing:
- low vacuum - like 12" instead of 18-22"
- rough idle, but runs well above idle
- slight over-heating
- white smoke puffing out of the valve cover

What cam is in this? That vacuum is awful low. Was the cam degreed in?

White smoke = coolant. Are you sure it is white and not grey? Grey = oil, black = gas. Rings could not be sealing 100% yet.

Look at yiur IAT intake air temp something is wrong with that sensor, location wiring something cause if your reading 196 your in Hades

If it was sitting and idling hot with the IAT in the stock location, then if could possibly be that hot.

[CobraMarty]

IAT - 196

That's about right for idling with stock air box or open element under the hood. Boy that's hot. Need cowl intake. But it's not your running issues. Maybe just need to let it 'break in' more.

[bulfo4]

IAT - 196 - you guys are right about it being hades! I misread the pic from my phone or mistyped it in, IAT was actually 126. We have a snorkel on it and an air filter canister that both allow more airflow than stock. Good catch. Doublechecked the other numbers and everything else is correct.

The engine came from Golen engine service (they've been super helpful so far but we're all stumped). The cam's a Comp Cams Hydraulic Tappet (have to admit I don't know what that means). We went with a long block rather than building it ourselves because we figured that was a bit over our heads. (Unfortunately, we're somehow still over our heads anyway). It's supposed to be a great engine, lots of good talk about them, and they make a lot of em. (http://www.golenengineservice.com/docum ... %20LB.pdf/) Not sure if the cam was degreed in or not. We did the 20 mile break in with Joe Gibbs break in oil like we were supposed to though.

The smoke is almost if not totally gone away now that the 63mm tb is on there. It was pretty white and didn't feel oily or smell sweet like coolant. It was suggested by a friend that could just be some condensation evaporating off.

The vacuum part of this whole equation seems to be really confusing. We've sprayed around and checked for leaks and keep coming up with nothing.

For letting it break in more, or letting the computer adjust to changes (has been reset a couple of times), how long are we talking about before things settle into place and the computer's adjusted? Drove it to work and back, about 30 miles, and it still wasn't happy.

Before I get new tags I have to get the emissions tested. I was going to wait till this gets fixed, unless there's some info you guys think the emissions place could give that's useful.

Thanks! T

[SilverXJ]

The smoke could be some condensation, but it should have burnt off with the cam break in. There are also several versions of Comp Cams for this engine.

On the vacuum, what does it idle at? If the idle isn't high I would doubt a vacuum leak.

I don't think its a PCM learning issue nor a break in issue. The rings should have mostly seated during cam break in and while the PCM takes time to learn it wouldn't effect the vacuum to this extent.

May do a leak down test? Or re check the compression test as it should have come up from 90psi.

[bulfo4]

Thanks for the suggestions, SilverXJ.

For the vacuum, it's pulling pretty steadily 11-12" at an idle speed of 778rpm. We're at about 5,000 ft elevation which I understand subtracts about 1" per 1000 feet (if I read correctly). On the vacuum gauge, it says 'late ignition timing' for 14-17", just below the green area of 18-22", and adjusted for altitude, we ought to be in the 'late ignition timing' category. We'ved re-indexed this engine more times than I can count and +/- 1 tooth it either won't start at all or runs REALLY terrible. This makes the think it should be indexed correcly (and we've doublechecked that we're not 180 off).

Someone at work had suggested maybe the exhaust was blocked up so I disconnected the headers from the exhaust and the vacuum wasn't any different and everything else was about the same.

It's not sounding terrible any more, and starts fairly reliably. The pita 3-fan kit we installed, when it's unplugged gives it about another 1" of vacuum, and we thought about taking the 3-fan kit out and going back to the zj fan clutch/stock electric setup we had before.

We'll try re-checking the compression wet/dry and see what those numbers look like, and I might see if this week I can get the equipment to do a leak down test.

Any more suggestions are greatly appreciated.

Thanks!

[bulfo4]

Not too productive of a weekend. We took out the 3-fan kit and after some hiccups, went back to the ZJ fan clutch and stock electric fan. This approach to cooling worked pretty well before the new engine.

Drove it around and it gets hot on moderate hills (nothing serious), and at stoplights, but cools off quickly going downhill or once there's airflow again.

Vacuum's probably 3-4" low which the gauge says 'late ignition timing'.

Feels very under-powered, like a stock engine that doesn't have much oomph left in it - nothing like a stroker.

And from the outside it's not too noticable, but inside the vehicle, it shakes a lot more than it should, especially at idle.

Going to try to re-index it again for kicks, see if I missed something there, and if the compression gauges will cooperate, will check compression.

[ossme]

Interested to see how things will end up.