Horrible miss need help!!!

JohnnyBeGood · Sep 18, 2012

I posted this on PSN but I do alot of poking around here and know there is alot of knowledge and experience on here as well so I figured I'd go ahead and through it up here too.

Quick run down of my truck's problem. Mods are in sig.

The truck started having a miss at idle and low rpm about a month ago as well as what sounded to me like "injector knock", so I replaced the injectors with a set of rosewood 160/100's and also installed an adrenaline hpop and intake/pre-pump kit new vcg uvch and orings on the entire fuel system, as well as some beans custom tunes. The truck had kinda of a slight miss and just general rough running. I assumed this was just because of all the air in the oil and fuel system so I really didn't think much of it. However it has now been over two weeks and roughly 400 miles and the truck has actually gotten worse. It has a horrible miss which sounds to me like it may even be on multiple cylinders. At first I thought it might be a tuning issue as some tunes seem to run worse than others however I changed the oil this past weekend and also had the drivers side vc off just to take a peak and see if maybe an injector plug wiggled loose or something. After I changed the oil(and with the driverside vc still off) I started the truck and it ran much better. It still had a slight miss but sounded much smoother and didnt stumble at start up. So I turned it off and was tinkering with my driveshaft for a bit, then when I went to leave it started running like $h*t again. It being intermittent and slowly getting worse tells me it isn't the tunes so I assumed it must be an electrical issue, so I pulled out the multi meter and ran the resistance tests as per thie service bulletin http://www.gbreman.com/docs/techbulletins/GB_Tech_Bulletin_103_Ford_IDM_Replacement.pdf
and everything seemed to be within spec
Drivers side
(inj#2)3.6ohm
(inj#4)3.7ohm
(inj#6)3.7ohm
(inj#8)3.6ohm

Pass Side
(inj#1)3.6ohm
(inj#3)3.6ohm
(inj#5)3.6ohm
(inj#7)3.7ohm

I'm stumped and don't know what else to try. Heres a video I made yesterday after work. I need this thing fixed it's my DD and I don't like driving it like this but don't have a choice. Sry for the essay just desperate for help.
http://www.youtube.com/watch?v=MpGg3KLkUdU&feature=plcp

David N · Sep 18, 2012

Sounds just like my truck... When you go from split shot injectors to single shot injectors, the tone of the motor changes alot. It sounds normal to me.

Or maybe I just can't hear it?

JohnnyBeGood · Sep 18, 2012

I know it changes and it definitely has much more of an old school "mechanical" tone to it but it really feels like a horrible miss fire. Sometimes worse than others. Sometimes I'll pull up to a stop light and it'll be loping and missing so bad that it's shaking the whole truck like my old drag car with a .620 lift cam did. It feels like it runs worse then when I first did the swap and has alittle less power. And if you're cruising at light throttle some times you can feel it stumble and buck.

BDP Tuner · Sep 18, 2012

When it is running bad is the ICP jumping around?

Also have you check fuel pressure and do you plan on putting a RR fuel system ?

TARM · Sep 18, 2012

When did it very first start? It seems by your posst it started before the injects hpop etc... did it start maybe right after a hard run?

Point is if it was doing it before then its doubtful anything you changed is the cause as it had no effect on the actual issues themselves.

I can clearly hear the knock and the stumbling you are referring to. When you walk around the engine. What bank does the knock seem to be coming from?

Have you tried swapping a known good ipr with yours?

Have you tried unplugging the icon to see the effect?

A was suggested already have you checked your fuel psi? Make sure its ssteady as well not surging.

I did have that same type of stumble when my fuelab pump went bad. Not the knock though.

TARM · Sep 18, 2012

Going thru the video again it sounds like the knock/miss is noticeable when you are over on the passenger side bank.

woodduck97 · Sep 18, 2012

Sounds just like my motor. How many miles are on it?

JohnnyBeGood · Sep 18, 2012

TARM said:
Going thru the video again it sounds like the knock/miss is noticeable when you are over on the passenger side bank.

Its funny you say that cause when the stock AD's were still in there it had a slightly louder knock coming from the drivers side.

ithumpwheniwalk · Sep 18, 2012

woodduck97 said:
Sounds just like my motor. How many miles are on it?

yep, mine sounds absoutely identical... same tick on passenger side and everything. mine doesn't miss though :shrug:

JohnnyBeGood · Sep 18, 2012

BDP Tuner said:
When it is running bad is the ICP jumping around?

Also have you check fuel pressure and do you plan on putting a RR fuel system ?

The ICP does jump around in the "heavy tow" tune(which seems to run the best of all 6)at idle it is jumping around between 440-487.

I haven't checked fuel pressure as I dont have a mechanical gauge yet. And I am planning on getting a rr with bowl delete but I don't want to spend anymore money till I get this problem sorted out in case it ends up being an expensive fix.

JohnnyBeGood · Sep 18, 2012

woodduck97 said:
Sounds just like my motor. How many miles are on it?

just hit 190007 as I pulled into work this morning. Have maybe 500 after today since putting it back together.

JohnnyBeGood · Sep 18, 2012

Correction in the heavy tow tune icp seems to be around 520-550. Old numbers were with knock off icp sensor. New numbers are with ford icp.

JohnnyBeGood · Sep 19, 2012

Bump. Any new ideas? I've got a bald spot from scratching my head so much and a knot from banging my head against the wall so much.

golfer · Sep 19, 2012

if it has a miss...and there isn't a constant CEL/SES light on...

then it's either an injector issue, or an engine issue.

since it's not pissing white smoke (like an engine with poor compression on a cylinder would do with 8 working injs...) that leaves the inj(s) as the likely culprit.

the idle honestly doesn't sound horrible for what you have...went up 15cc's in injector volume, but doubled the nozzle size.

but if it has a hard miss under acceleration...probably an inj issue.

JohnnyBeGood · Sep 19, 2012

It seems to stumble and miss more at idle and when you let off the throttle than under acceleration. Its really bad when you let off the throttle in the DD and hot tune. I mean Ugly sounds like its gonna die. And I also don't understand why whenever I first start it it runs like a an detroit thats could. That rough blower kinda idle. It only does it for a few seconds and then it goes to idling like in this vid but it runs really terrible when you let off in dd and hot. Maybe this is just a tuning issue. Wish I didn't have to keep pulling my chip sending it in and waiting over a week. This is my DD I know with extensive mods it takes some fine tuning but damn stage 2's and a hpop seems like a very common set up. I have the cash for more air but I'm scared to spend it. Maybe I should just pull the injectors and send them to jim to have him flow test and inspect them. Maybe time to try a different tuner? I really wanna give matt a try and feel like maybe I should have in the first place but man $235 is a hard loss to swallow plus $175 for the new tunes. Grrrrr

JohnnyBeGood · Sep 19, 2012

golfer said:
if it has a miss...and there isn't a constant CEL/SES light on...

then it's either an injector issue, or an engine issue.

since it's not pissing white smoke (like an engine with poor compression on a cylinder would do with 8 working injs...) that leaves the inj(s) as the likely culprit.

the idle honestly doesn't sound horrible for what you have...went up 15cc's in injector volume, but doubled the nozzle size.

but if it has a hard miss under acceleration...probably an inj issue.

Its definitely not a compression issue I don't think. I've done the cap upside down thing and it vibrates off. There is extremely low blow by. Should I check for maybe a broken valve spring? Could that cause similar issues?

I think I really need to check fuel pressure next.

David N · Sep 19, 2012

JohnnyBeGood said:
Its definitely not a compression issue I don't think. I've done the cap upside down thing and it vibrates off. There is extremely low blow by. Should I check for maybe a broken valve spring? Could that cause similar issues?

I think I really need to check fuel pressure next.

I regulated return and proper fuel pressure will quiet those injectors considerably as well.

And honestly, when I had beans tunes, my truck would romp and idle all funny after a "hard" or "semi-hard" run. Maybe this is what you're describing? I switched to Matt's tunes and it hasn't done it since.

JohnnyBeGood · Sep 19, 2012

Ya screw it I'm kind of disappointed with communication too. I guess that was a $235 lesson :fustrate:

TARM · Sep 19, 2012

Dave,

Could a bent push rod cause something like this or is it most likely injectors related? I guess it would not cause stumbling though would it?

JonnyBeGood,

Are the injectors from Casserly (Full Force)? If there are from one of the main guys on here you should have not issues getting them corrected.

JohnnyBeGood · Sep 20, 2012

TARM said:
Dave,

Could a bent push rod cause something like this or is it most likely injectors related? I guess it would not cause stumbling though would it?

JonnyBeGood,

Are the injectors from Casserly (Full Force)? If there are from one of the main guys on here you should have not issues getting them corrected.

They are rosewoods, I bought them second hand but I have been communicating back and forth with Jim and he said send them to him and he'll go through them and flow test them, I just pay shipping and whatever parts need to be replaced if any. Think when I send my chip to matt I'll pull the injectors and send them to jim at the same time.