Using stock ignition and tuned on crome, base fuel pressure @ 50psi. Using RC 750s. Timing at 16 degrees. Haven't ever had any issues with my tunes so far.

I installed a Blox Intake manifold. Ever since then I have had tons of issues with high rpm breakups during tuning. My old tune with the new mani made me run lean, but everytime we try to add fuel the car noticeably loses power and breaks up after 6000rpms. The only thing that made it run somewhat normal was to pull timing and take away fuel. It seems like my motor will only run normal under very lean conditions now. Plugs are good, distributor is new and injectors haven't ever given me any problems.

I also had an injector leak, which I believe is because of the manifold. Also had a vacuum leak which I fixed before the last tune. I am putting the stock mani back on, and I ordered a new set of oem plug wires.

We have tried to tune this thing twice now with crappy results each time. Any input on this?

 

Datalogs?

If you have the correct information, you can find the problem. I can't see the intake manifold causing an ignition breakup, but without more information, its like having a blind tuner.

 

did your base timing come out of calibration?

ive got a blox im and havent had any issues. um, did you double check all connections and stuff, iacv, tb and crap

 

Yeah I'm going to set my base timing again before we start another tuning session. Hopefully I will get the wires in this week and can go from there. I just check the damn manifold again and there is still a slight leak in the #3 injector. Not sure if its the seal or what, I have some seal coming in the mail too. I don't have datalogs, I will make sure to get some after this next tune. It easy driving until then

 

what's ur fuel system? upgraded pump? what kind of spark plugs and gap? alittle bit about ur setup would help too

 

Walbro Fuel pump, RC 750's at 50psi base pressure. , ngk bkr7e's gapped at 20, we had them at 30 before but wanted to try a closer gap. Its a stock b18b, running 10 lbs, on a t3/t4e 60 trim, 63 ar.

There were no issues before adding the IM. I'm taking the manifold off tomorrow. It still has a leak at the #3 injector.

 

.020 is a tight gap for that boost pressure and power level in my opinion. what about like .026 or .028? thats what im running on my friends gsr and its working very well

 

I put the gap back to .30 today, nothing changed. I'm gonna open open the dizzy tommorow. It has to be the cap, rotor, or ignitor. Or base timing. This has to be ignition related.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jake1220 &raquo;</TD></TR><TR><TD CLASS="quote">I put the gap back to .30 today, nothing changed. I'm gonna open open the dizzy tommorow. It has to be the cap, rotor, or ignitor. Or base timing. This has to be ignition related.</TD></TR></TABLE>

Not really. The issue could be related to fuel aswell. Get a wideband on the car asap.

 

Well the cap and rotor looked fine, there weren't any visible problems anyways. It a new remanufactured dizzy. I noticed the fuel pressure gauge bouncing a little bit at idle, but my idle still isn't perfect, it fluctuates a little, but I can't find any vaccum leaks. We've had the wideband on there. The car feels like its hitting a brick wall after 6k if we run it rich. It feels a lot better running lean (12.9-13.0) and retarding the timing from what it was tuned at before, when it ran perfectly. Obviously I'm not going to let my car run lean.

 

use 0.025 - 0.03 gap
pull some timing and retune afr

it might be breaking up at top end b/c your gap was to small (0.020) and you are dumping way to much fuel

reason why it was running lean before is probably b/c of the increase airflow from the new manifold

 

While your debugging issues,

What fuel pump are you running ? I'd check that as well ..


Modified by TheWickedOne at 1:55 PM 9/18/2007

 

Fuel Pump is what I'm checking next as well. A couple weeks ago I was driving and didn't realize I needed a fill-up. While boosting I experienced major fuel starvation, wondering if this expletived up the pump

*Edit*

I'm starting to think this is it, I did starve it pretty bad twice. It still works, but I should have a new one to throw in by thurs.


Modified by Jake1220 at 4:32 PM 9/18/2007

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jake1220 &raquo;</TD></TR><TR><TD CLASS="quote">Fuel Pump is what I'm checking next as well. A couple weeks ago I was driving and didn't realize I needed a fill-up. While boosting I experienced major fuel starvation, wondering if this expletived up the pump

*Edit*

I'm starting to think this is it, I did starve it pretty bad twice. It still works, but I should have a new one to throw in by thurs.


Modified by Jake1220 at 4:32 PM 9/18/2007</TD></TR></TABLE>

Very good possibility, I'm assuming you have a walbro 255hp ?, It may be difficult to do while your driving, but a good quick test is monitoring the fuel pressure on a dyno under boost. It should go up 1:1, PSI/Fuel Pressure. If your fuel pressure is not increasing, your pump is failing..

Good Luck

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mtber &raquo;</TD></TR><TR><TD CLASS="quote">

Not really. The issue could be related to fuel aswell. Get a wideband on the car asap.</TD></TR></TABLE>

Keyword... WIDEBAND

 

I don't have a wideband, but I have had one on the car twice since I started having these issues. Basically the car started leaning out really bad at around 6k. I thought this was due to the IM that I had put on, maybe it was the IM and the fuel pump. I'm putting in a new pump tomorrow and taking of the IM tonight. Probably going in for the retune fri-sat. I'll keep you updated.

 

Well I'm running well again. Seems like I just had a bad spark plug. So happy thats all it was...

 

I love happy endings

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jake1220 &raquo;</TD></TR><TR><TD CLASS="quote"> I just check the damn manifold again and there is still a slight leak in the #3 injector. </TD></TR></TABLE>

Vacuum leaks at the injector in the intake manifold will cause massive break up issues...I have seen it many times.

 

lol how in the hell do you know your leaning out without a wideband retard.. narrowbads arent accurate for ****.. quite bieng cheap and get a lc-1 or plx m300

jesus they never learn

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by THEDirtyDseriesWOOT &raquo;</TD></TR><TR><TD CLASS="quote">lol how in the hell do you know your leaning out without a wideband retard.. narrowbads arent accurate for ****.. quite bieng cheap and get a lc-1 or plx m300

jesus they never learn</TD></TR></TABLE>

lol how in the hell can you talk **** when you haven't read everything correctly...Did I say I have a narrowband??? retard...

 

i didint see anyhting about wideband..

but i re read and i saw sry for the bullshit..

 

Its all good. But about what Xenocron was saying, I'm gonna keep close watch on that manifold. I'm still not sure if the spark plugs were the main issue or not. I've used a whole can of carb cleaner checking the injectors for leaks everyday since I fixed them, but they still could be leaking intermittently. I'll keep it updated.

 

look for hairline crack in the mani.. i had one in the number 4 runner and you couldnt see it from the outside but damn sure on the inside u could see the crack .. made it idle higher mad ethe turbo work harder and it was missing a lil u top.. . might wanna check the runner with that carb spray

 

I'm gonna have to buy more carb cleaner now. My idle is still fcked up. It fluctuates slightly from 7500-1200. It either that injector only sometimes, or I have a leak from underneath the mani. This is annoying.


Modified by Jake1220 at 3:27 PM 9/24/2007