Pullig

Im looking to get some outside advice ive done everything ive known possible to remedy an issue I am having.

setup is this b18c forged flat top cp pistons eagle rods, type r head with ferrea 100lbs springs and ferrea valves. edelbrok intake manifold
GSC Turbo cams Degreed in plus 3 deg exhaust minus 3 intake
ngk 7 resistor plugs gapped .020 110octane on NEPTUNE
go-autoworks pro ram horn kit with 62mm turbo

Motor was prev tuned on stock type r cams around 30lbs of boost
added these cams and no im getting a strange misfire hesitation at low vtec enagement vtec engagement anywhere from 4500-5800 misfire hesitation vtec set at 6k runs good and hard boost isn't crazy 11-14lbs
I had vtec set on my type r cams at 5k no problems
afr is 11.7 during this issue and it happens no matter if I partial throttle engage or full throttle engage

im still on stock ignition setup

Pullig

ive tried pulling 5deg of timing out of the area this is happening no change.... ive added 4 deg no change im at a total loss on this

LightningTeg

You probably shouldn't be arbitrarily throwing 4 degrees of timing at it unless you are reading plugs or on a dyno. Good way to blow the motor.

This is tuner issue. curious why you have the cams not at 0 - 0?

Javcolin

As far as i know, and i just bought a set of GCS's they are drop in, no degree needed, actually there is a post from The Shodan, that shows a video with the cams set to 0-0 and a video with some sort of dedree on them. and you see a big diference, from one and the other.

Worth having a look at that post.

TheShodan

iTrader: (14)

Correct. These need to start of at 0,0 unless the head/block had been milled to adjust for that change. They shouldn't be at the settings that they are at initially. That can cause a big problem.

Pullig

Head and block has been milled. It's been sleeved. Also I know how to read plugs. Another thing this isn't happening at any type of boost pressure Plus I'm on race gas. I'm not too worried for short duration Not like I'm beating it too hell. Like i said it does this at partial throttle engagement.

I degreed the cams exactly where the spec card said to place them.

Pullig

Also having to take a car to a dyno and it not being ready because of mechanical or electrical issue is not something I want to. Which is why I messed with timing trying to figure out if I could get some type of improvement.

The motor is sound mechanically. 170-180psi comp across the board. Runs rather well beside the issue I have described

TheShodan

iTrader: (14)

The misfire is what's sticking out to me. I'd check for the ignitor/distributor setup. I know it may be stock, but here, I'd look into adding in some digital ignition and external coil to enhance the stock system without resorting to coil-on-plug, which may be much more outside any budgetary concerns.

Dark_Teg

A lot of times issues at part throttle that cant be tuned out are TPS related. Your sensor could have a dead spot.

TheShodan

iTrader: (14)

I would only concur if they are using some sort of after market TPS or the wires are somehow compromised. I've never seen random misfires from Denso TPS sensors. I'd look at the area of "spark" first before going to the TPS hardware. If the TPS is off, then that's more software related, which means more than likely that the issue is surrounding the area that is more tuning related. you know?

Dark_Teg

Sometimes an engine bogging down is misconstrued as a misfire is what I was getting at, but you are probably correct.

Pullig

Stock type r throttle body with stock tps. Already went through full range of motion no issues. Like I said moving vtec 6k or higher completely fixes the issue. Honestly timing and fuel is very similar between 4800 and 6k Even fuel.

I already have icm delete and digital ignition setup sitting in some boxes ready to go on. Just didn't want to complicate this situation. I may try to put the cams at 0 - 0. But didn't want to just go moving them around when It's safe now.

wshuculd

Put it on the dyno. My gsc cams are set at 0. Your tuner needs to spend some time dialing in the cams. When mine was breaking up I put a new igniter in and fixed the problem

Pullig

well it could very well be an igniter issue. But I just find it hard to believe when it ran just fine before cam install. At this point I'm not trying to make the most power or be optimal. I just want the thing to run right that way I'd feel more comfortable before spending time and money on a dyno.

TheShodan

iTrader: (14)

It's also more about reliable/repeatable power. You more than likely need to see about the igniter and for your tuner to check timing via the software, not physical.

LightningTeg

The sudden change in VE could be blowing out the spark. My buddy had the same problem on his old distributor and Pro 1s

Pullig

man I hope so. I guess the next course of action will be to install icm delete with the Mallory dig 6 see what it does

TheShodan

iTrader: (14)

I'd do that anyway.

Pullig

Just to update. Upgraded Ignition setup installed with icm delete.

1. Problem is still there exactly the same issue as before.
Decided to do a test advance intake cam in 2 deg slightly better
so I'm assuming it's going to be cam position related


Issue 2.
I did not wire the tach output from ignition box Tach works ecu reads rpm

but have an issue in the upper rpms where the tach is dropping out
do I have to wire in the tach output wire?

In all the times I've dealt with digital boxes, I always had the tach output wired up. I'm not a wiring specialist, but from working with some people on these, yes. Hook those up.

As for the camshaft timing relation, it's more than likely you weren't at theoretical 0,0. But did you change timing via the software as well?

Pepe14

Youre probably not active anymore but any resolution to the issue?

Pullig

Vtec is just set too low with my ram horn smallish 6262 turbo setup. Raised vtec to 6k rpm good to go. You could probably lower vtec with a larger turbo and bettter top mount manifold.