Will Cams Make My Car Shut Off(see inside)

[spadepro22]

So I got a fresh rebuild and just about everytime I'm coming to a stop the car shuts off like I took the key out. Push in the clutch and the car shuts off, let the rpms drop and it shuts off. Would the kelford 272s cause this problem just with injector global and deadtime set? Most of the time it cranks back up, but some times I have to turn it over and over. Once it starts it idles ok and if I push the clutch in at idle the rpms drop some.

 

[DRTredHEAD]

Are you still using the MAF or are you SD? If your maf make sure you havent clamped your maf too low i did that once on accident and the same thing happened. Its in your air flow tune somewhere. Your engine is seeing more air from the cams and if you haven't tuned for it thats what will happen.

 

[okm12346]

My car did this right after the rebuild, maybe for the first 2-3k miles. I had hard cold starts and when i let off the gas it would stumble and die, and the FIAV/ISC was blocked off. I had the habit of tabbing the gas pedal right before it drops to 1k rpms so the engine finds itself. In my opinion, it was due to the new/fresh surfaces matching and the extra friction from the new parts - rings, bearings...etc. It was all fine after some time. Same with the clutch and dropping rpms - it disappeared after time.

 

[YanDsm]

I think that it's a mix of lightweight flywheel and cams. I suggest to rise your idle speed to atleast 1000rpm and increase the Coasting FC offset until it stops to stall. That's what I did on mine and now it never stall.

 

[spadepro22]

I have it idling around 800rpms. The bov isn't recirculated but will be tomorrow. Please don't flame me and say thats the problem(worked fine before the rebuild). I know it has alot to do with it and will be fixed tomorrow if I can find the right pipe to fit. I just think that even in reverse it stalls and its just more than the bov.

 

[Calan]

Post a log of it dying while coming to a stop.

How many miles are on the rebuild?
How did you break it in?
Where is the WB sensor mounted?
Have you thoroughly checked for boost and exhaust leaks?

 

[spadepro22]

Post a log of it dying while coming to a stop.

How many miles are on the rebuild?
How did you break it in?
Where is the WB sensor mounted?
Have you thoroughly checked for boost and exhaust leaks?

115 miles on rebuild, broke it in by boosting up to 10 psi and 2,500 to 4-5k couple times then a 90mile ride home. Wb sensor mountd behind steering wheel in the middle(in front of factory oil pressure). Boost leak after o2 where the o2 and downpipe meets. Can't seem to fix it. It was there before the new motor and I put new gasket and OEM bolts. PR said there flanges probably aren't warped on the recirculated o2 housing. Being after the o2 doesn't seem like it would make it stall and it didn't stall on the old setup. 4ply couplers from ets everywhere with t- bolt clamps, new biss o-ring and tb gaskets. New injectors and seals.

 

[Calan]

115 miles on rebuild, broke it in by boosting up to 10 psi and 2,500 to 4-5k couple times then a 90mile ride home.

Just two pulls to 4 or 5k and then an easy 90 mile road trip? So you didn't follow the motoman method, with plenty of engine braking from around 5k or so like everyone recommended in your other thread?

Wb sensor mountd behind steering wheel in the middle(in front of factory oil pressure).

Huh? That makes no sense.

Are you talking about where the gauge/display is? If so, that's irrelevant... where is the sensor mounted?

Boost leak after o2 where the o2 and downpipe meets. Can't seem to fix it. It was there before the new motor and I put new gasket and OEM bolts. PR said there flanges probably aren't warped on the recirculated o2 housing.

Depends on how far from the sensor it is. It's not "causing" the stall, but it isn't helping any. Try harder to fix it.

 

[spadepro22]

Calan;Just two pulls to 4 or 5k and then an easy 90 mile road trip? So you didn't follow the motoman method, with plenty of engine braking from around 5k or so like everyone recommended in your other thread?

We did 10 miles of them and I did some on the way home. Bboosted several times

Calan;Huh? That makes no sense.

Are you talking about where the gauge/display is? If so, that's irrelevant... where is the sensor mounted?

Yes in front of the gauge display and the 02 is in the front 02 and I'm using v3 to sim narrowband.

Calan;Depends on how far from the sensor it is. It's not "causing" the stall, but it isn't helping any. Try harder to fix it.

Correct not helping and I've tried new bolts, gaskets, tried tighting the bolts evenly to keep the downpipe lined up on each side. What else to try? Believe me, I want the stupid car fixed and a professional shop has done all the work.

 

[HIGHPSI4]

As for the down pipe leak, you may have to find out what part of the flange is hitting first and how big is the gap that won't seal. Have you losened up the whole exhaust so that you can move it around to adjust the gap? If the leak is facing the engine then you can not lift up the exhaust more to close it. If you have to, you can clean both flange surfaces and take some material that will transfer from one surface to another (like chalk) and bolt the DP up with out the gasket. Take the DP off and see where the gap is and then grind the DP flange in the contact area to reduce the gap. Some people have heated up the flange and bent it some to allow clearence in the contact area.

 

[spadepro22]

Recirculated bov today and set idle to 1000rpms and it helped some. Still cutting off when the rmp drop when coming out of gear if I don't keep it reved to a certain level. Here is a log, Im pretty sure it was cutting off in here at least a couple times.

 

[Calan]

No log in that last post, but your previous one shows no airflow calibration, stock DA tables, etc.

 

[JusMX141]

If you changed nothing about your tune when you installed the cams, then the answer is yes.

Increased cam overlap will draw in more air and lean out your idle to the point where you may need a complete re-tune. This is why it's not wise to install cams on a car that has the stock ECU and no way to tune.

If you have a wideband it will tell you right away whether your idle got lean on you or not. A lean idle will also make the engine "lope" like crazy until you add some fuel.

 

[MY1GDSM]

Obviously you want to address any mechanical issues or things like the leaking down pipe. But the short answers to the actual threads tittle and question.

If this is not the case v is No... .

No airflow calibration, stock DA tables, etc.

This ^ is the your problem more then anything IMHO...

You can't have the expectation (not necessarily saying you do) that you can modify your car and still have the "stock" tune and just toss in a global and dead-time number. I see time and time again people post logs of there cars un-tuned asking why their cars are doing things like this. And most don't want to accept the fact that if the car is tuned correctly these things won't happen flat out... . They think that like a lot of Dsm quirks it's something that they have to live with or is caused by something directly that can't be remedied... .

 

[T is for TURBO]

Obviously you want to address any mechanical issues or things like the leaking down pipe. But the short answers to the actual threads tittle and question.

If this is not the case v is No... .



This ^ is the your problem more then anything IMHO...

You can't have the expectation (not necessarily saying you do) that you can modify your car and still have the "stock" tune and just toss in a global and dead-time number. I see time and time again people post logs of there cars un-tuned asking why their cars are doing things like this. And most don't want to accept the fact that if the car is tuned correctly these things won't happen flat out... . They think that like a lot of Dsm quirks it's something that they have to live with or is caused by something directly that can't be remedied... .

^ Good advice ^

I would never want to run my car on global and dead time adjustments alone. Mine ran like total shit until I got all the quirks worked out. TB shaft seals replaced, TPS properly calibrated, proper throttle cable tension, properly working ISC, properly set BISS. Plus, the dead times I ended up using were fairly different from the "recommended". Can't over look the small stuff. Once it was all inline, the car ran beautifully! Also, it makes WOT tuning 100x easier, when everything else is inline.

 

[spadepro22]

It was tuned on the old setup, and I know it will need retuning . I'm asking to see if the cams is whats causing the stall problem as I'm trying to work all of the bugs out so a can get a good tune. Was told I'd be fine running off global and deadtime for break in.

 

[T is for TURBO]

It was tuned on the old setup, and I know it will need retuning . I'm asking to see if the cams is whats causing the stall problem as I'm trying to work all of the bugs out so a can get a good tune. Was told I'd be fine running off global and deadtime for break in.

So long as your A/F ratio is okay, than yes, it should be fine, if you're doing the motoman method. I followed AMS' break in instructions, so I spent the extra time getting my base tune dialed in.

But now that you're broken in, go over your base tune. you changed you're airflow characteristic, so you will need to re-base tune. Are you running a MAF still? or SD?

 

[spadepro22]

Are you running a MAF still? or SD?

Maf.

 

[T is for TURBO]

Maf.

Right on. On my setup (HKS 272/272) I had to do a significant amount of tweaking to get it right. Mine never died, but the idle was real rough and had a lot of misses. I'm not familiar with kelford cams, so I can't comment on their behavior. Curious, what kind of vacuum are you pulling @ 1,000 rpm idle?

 

[spadepro22]

Right on. On my setup (HKS 272/272) I had to do a significant amount of tweaking to get it right. Mine never died, but the idle was real rough and had a lot of misses. I'm not familiar with kelford cams, so I can't comment on their behavior. Curious, what kind of vacuum are you pulling @ 1,000 rpm idle?

10 on vacuum, what about you.

 

[trillatl]

The following tables illustrate how variations in lobe separation angle and cam timing will effect the behavior of the engine in which the camshaft is installed.

Technical Specs & Information

 

[T is for TURBO]

10 on vacuum, what about you.

More than that. I think 14. I'd have to look at one of my old logs to verify that.