highway cruising problem

Post by **sjbsuperman1425** » Thu May 19, 2011 5:33 pm

Ok, so my car runs, but when cruising at highway speed its hard to keep a steady speed. Its like I have to be in boost all the time to maintain a speed of 75-80mph and its bugging me...

My timing is good, i set that last night.
It does have a misfire but I have yet to pinpoint whether its the plugs, coilpacks, or ignitor.

Any other ideas?

Post by **float_6969** » Thu May 19, 2011 7:55 pm

O2 sensor? Minor vac leak? Do you have a vac/boost gauge? Does it seem to give you problems right around atmospheric pressure?

Post by **sjbsuperman1425** » Thu May 19, 2011 8:29 pm

Yea it does, it stumbles coming into boost and around atmospheric. O2 sensor was replaced when I did the swap 3 years ago?

Post by **D_Stirls** » Thu May 19, 2011 11:27 pm

I had the exact problem when i first bought my 180 and it turned out to be a faulty O2, it was pulling fuel when it was already lean and then it wouldn't run right until i put in enough throttle percentage to revert to the open loop and run off the Maps.

Post by **float_6969** » Fri May 20, 2011 5:41 am

^This

Or maybe a FPR, but most likely a bad O2 sensor. Do you have a wideband? What do the AFR's look like when it breaks up?

Post by **sjbsuperman1425** » Fri May 20, 2011 9:17 am

Yea I have a wiseman but the shop that installed the bung in the exhaust didn't make the hole big enough so I don't have the sensor in and calibrated yet. That will happen Monday.

On another note, on my way to work today the car drove fine and I had no problems. Cruising vacuum around 5-6" at 80mph

Post by **float_6969** » Fri May 20, 2011 11:20 pm

That's wierd. Now it sounds like an electrical problem. Grounds are all good?

Post by **sjbsuperman1425** » Fri May 20, 2011 11:53 pm

Yup, grounds are all good.

Post by **s13drifter88** » Sun May 22, 2011 10:30 pm

i had this same issue right after i finished my swap. it was a bad O2 sensor

Post by **sjbsuperman1425** » Mon May 23, 2011 10:46 am

im really hesitant to condem the O2 sensor since I replaced it pre-swap and its only been 3 years..

I still haven't gotten my wideband in yet (Wednesday for sure). Any other ideas besides grounds and O2 sensor? I have a little trouble having it start on Cold-starts, but once it gets idling its good and will cold idle at around 1400rpms. But once its warm and in closed loop, it idles around 8-900rpms and has a misfire, and of course the intermittent troubles on the highway im having..

Post by **D_Stirls** » Mon May 23, 2011 10:58 pm

I know you don't want to hear about the O2 sensor, but there is a way to test it. If you unplug the O2 sensor the ECU will run off maps all the time. If you have it unplugged and it still has the same issues then it isn't the O2 sensor.

Post by **sjbsuperman1425** » Wed May 25, 2011 5:25 pm

I will disconnect my O2 sensor tonight and see how it drives on my way to work tomorrow. I also did get my Wideband hooked up and calibrated so I can finally see what my air/fuel ratios are. its pretty cool lol I get an a/f ratio of 14.0 on cold start.

Post by **sjbsuperman1425** » Thu May 26, 2011 10:00 am

Well I left the o2 plugged in and my afr's were around 14.1-15.6 and hit 17 at a couple times when in at about atmospheric..

Post by **sjbsuperman1425** » Thu May 26, 2011 10:02 am

Well I left the o2 plugged in and my afr's were around 14.1-15.6 and hit 17 at a couple times when in at about atmospheric..

Post by **Anu** » Thu May 26, 2011 1:50 pm

An AFR of around 17, was that after releasing throttle? Then it is pretty normale because no fuel is being injected right after releasing.
When it is under load then be very carefull not to damage anything because that is very lean.

Post by **sjbsuperman1425** » Fri May 27, 2011 5:58 am

What about fuel filter?

Post by **sjbsuperman1425** » Fri May 27, 2011 5:13 pm

ok i'm thinking the fuel filter is the culprit. Not only do I have the problems on the highway, but even with city driving, when coming into boost, i get a LEAN misfire/sputter. A/F Ratios of over 16 at this area. I'm leaning towards fuel because its lean. What do you guys think?

Post by **float_6969** » Sun May 29, 2011 7:56 pm

So can you not get into boost at all? Does it lean out and then get rich, or does it break up and you can't get past it?

Post by **sjbsuperman1425** » Mon May 30, 2011 12:36 am

It just leans out around atmospheric. I can boost fine.

Post by **float_6969** » Mon May 30, 2011 8:30 pm

If it was fuel volume related, it would break up at high loads, but be fine elsewhere. I could be a failing FPR, but that's not likely.

Post by **boost_boy** » Tue May 31, 2011 4:12 am

Did you plug the vacuum nipple under the throttle body? Most people don't do that and their cars have strange little problems that they can't figure out because they've over-looked the little things. Sounds like a stinking vacuum leak to me. And the CA18 have a few areas that it tends leak from besides the the intercooler piping

.

Post by **sjbsuperman1425** » Tue May 31, 2011 4:39 pm

i blocked it off, but then again, idk how tight the thing is that I have on there. Replacing the fuel filter seems to help a little bit, but there is still a slight lean around atmospheric. I'll check out the TB nipple tomorrow.

btw, new thing happened today. the tach starts jumping around when i get into boost..damn car lol

Post by **cbh148** » Wed Apr 17, 2013 7:47 pm

bump -- whatever ended up being the culprit?

Post by **sjbsuperman1425** » Mon Apr 29, 2013 3:10 pm

well...its better now...i dont recall exaclty what I did, but I cleaned the grounds really good for the ignitor and all that area and the car runs fantastic. I still have to be almost to atmospheric to old 100-120km (about 80mph) though..which really bugs me. I think i have a couple more grounds to clean. I'm getting 19mph with my car too....i think I may change the O2 sensor like everyone was saying just to see if it helps at all

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