Exhaust leak is fixed, new plugs and wires are installed and the car seems to run fine as far as not running stinky rich anymore. I think it was just unburned fuel from the burned plug wires. Still can't get into boost without it breaking up though. I used the AC delco 43 plugs, gapped at .029. I'm building a hotwire harness for the pump, because I can do that for free, and I want to check what my fuel pressure is doing when I get into boost, so I'll be buying a gauge I can read while driving. If I can eliminate fueling as the issue, I can redirect my efforts back at spark. I do want to get a new MAF sensor and translator, but I'm still broke.
Hot air to intercooled...tuning after the fab work.
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keith theriot
Turbocajun
- Joined
- Jun 15, 2010
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- 117
you may have a leak in your intercooler piping, if you blew a hose or have any crack in the line it is not reading it thru the maf. may want to check that closely
Everything is brand new, but I'll triple check it just in case.
Checked all the intercooler plumbing and it's all good. I did notice my exhaust was starting to change tone though, and I suspected another exhaust leak. Sure enough, I found that it was starting to leak pretty good at the crossover pipe on the passenger side. I pulled down the crossover pipe, made some gaskets out of 1/16" 5056 aluminum (soft) by punching out two 2.5" slugs, then punching out 2" out of that. It left me with a 2" inside diameter washer that I could smash in that joint. Sealed the crossover pipe good! Now the "misfire" problem is even worse. The car builds boost so quick even at part throttle that it starts breaking up even sooner. Anything over 8 inches of vacuum and it starts to miss. If I hold it at 5 inches, it seems to run smooth but less power than at 10 inches of vacuum. My new ignition module and conversion harness should be here by Monday. Until then, it drives like a dream at 1/4 throttle or less, lol. My MAF reading doesn't jump around, even when it starts missing, and the MAF passes the tap test, so I'm thinking (and hoping) the ignition upgrade will fix my problem. My 02 readings are between 835 and 850 mv at full throttle until it breaks up, then it goes high for a split second then gets pulled down to about 750 before going back up. The ECM is clearly getting boned by the unburned fuel when it's missing and trying to compensate and bring it back into line.
I may have got the issue. I suspect my BOV is leaking. Time to ditch it and put in a block off plate and see what happens. If I ever decide that throttle response isn't what I'd like for autocrossing, I'll put a better one on that doesn't leak. Thanks, Keith, for suggesting that it may be a boost leak. I think you may be right!
keith theriot
Turbocajun
- Joined
- Jun 15, 2010
- Messages
- 117
if it is building boost so quick why are you still seeing vacuum? At idle you should be seeing 15-20 inch of vacuum, from there at any throttle you should be seeing less vac and then going into boost. you may want to try another gauge. if you are over boosting it will seem like misfire and causing damage to engine.
I should clarify.... If I mash the throttle, even from a dead stop, it hits 5 psi almost instantly and then starts going nuts with the missing. If I'm cruising (where I have better control over monitoring the gauge) I notice I can hold at about 10 inches before it starts going south. even at 5 inches or zero vacuum, the engine is not at all happy. Yet at any time if I mash it, instant boost. And by the way, I removed the BOV and fabbed up a blank to block it off and I don't hear that boost leak sound, but the car still behaves exactly the same. And the problem is not with the gauge, I assure you. It's a calibrated US Gauge I borrowed from work to help diagnose this issue. Back to square one. I was really hoping blocking off the BOV flange would at least help.
No disintegrations
Well-Known Member
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- Dec 27, 2015
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- 1,055
by now the plugs may be fouled black, but i've lost track. They look good?
I just put new ones in last week. Not even 100 miles on them. I can pull the 3 easy ones later to check up on them, but my O2 usually reads 790-830 mv when I'm cruising on the highway, so they should look good.
No disintegrations
Well-Known Member
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- Dec 27, 2015
- Messages
- 1,055
That's fairly rich for just cruising around. Just don't overlook the plugs, because if you swap out a bad part it can still run poorly with bad plugs hiding the fix.
Plugs still look fine. Pulled out 1 and 3 while I was under the hood doing the ignition module and coil upgrade. So the new module is in and working and I also ordered a MAF translator and LS1 MAF from TT that should be here on Saturday. Also, I put extra grounds on the engine from the ground terminal on the driver's side fender and double checked my grounds from the negative terminal to the body and frame. If the new MAF sensor doesn't make this thing run right, I'm gonna be out of ideas. It literally runs like it did when I had a coupling pop off. It's gotta be a MAF issue. There are ZERO boost leaks now, 100% for sure.
Got the new LS1 MAF in with the translator and it's like a new car. No more stumbling, no more missing. I currently have it running 8-9 psi and it feels really good. I'm gonna start here with the tuning process. Right now at 9 psi my 02 readings start off at 830mv and as RPM continues to rise, it drops to 770 before I get out of it. I can't do a full pull, which is a bummer right now. The good news is that I have the fuel pump hotwire kit, just haven't installed it yet. So that's gonna be happening this weekend most likely. Once I can sustain 830mv, I'm gonna start turning up the boost until I reach the next point I can't keep up fueling with, or 16 psi, whichever comes first.
I do have to say though, I'm very happy with the throttle response and how fast it builds boost. Throttle body relocation is a MUST when intercooling a hot air car.
I do have to say though, I'm very happy with the throttle response and how fast it builds boost. Throttle body relocation is a MUST when intercooling a hot air car.
OK, I guess this is the finale to this saga. I found time to get the fuel pump hotwired and that solved the fuel dropoff issue. I was able to crank the boost up to 16 psi and now this car is running GOOD! Not super quick but it just pulls and pulls. If I was planning on keeping the car long term, I'd start upgrading the trans/converter and put steeper gears in the rear end to help get it out of the hole. I can only brake torque to about 2 psi with the stock converter, so it's a little doggy on the launch. Takes about 60 ft to hit over 12 psi, which is where it really starts to pull. On the highway it's a beast. Drop the throttle and by the time the trans downshifts the turbo is already pumping out 8-9 psi and it jumps to 16 within a second. I'm so glad I went with 3" for the DP.
So it all started with a guy who wanted to trade me this Regal for my POS Vette, and now tons of fab work later and another $2500 bucks ish, I got a fine running TR.
So as it stands now, the TR has new OEM head gaskets, 3" DP, external WG, 3" full exhaust, FMIC (vertical core), relocated TB, LS1 MAF with Translator, Turbo Tweak chip with 42 lb injectors, hotwired Walbro 190 fuel pump, '86-'87 style ECM and ignition with caspers ccci hotwire kit, Scanmaster G, and a buttload of custom fab work. Once the body and paint work it done, time to sell it and pay off the debt I went into to get it done and use the rest to get myself into something else.
So it all started with a guy who wanted to trade me this Regal for my POS Vette, and now tons of fab work later and another $2500 bucks ish, I got a fine running TR.
So as it stands now, the TR has new OEM head gaskets, 3" DP, external WG, 3" full exhaust, FMIC (vertical core), relocated TB, LS1 MAF with Translator, Turbo Tweak chip with 42 lb injectors, hotwired Walbro 190 fuel pump, '86-'87 style ECM and ignition with caspers ccci hotwire kit, Scanmaster G, and a buttload of custom fab work. Once the body and paint work it done, time to sell it and pay off the debt I went into to get it done and use the rest to get myself into something else.
Addendum...... Found a very minor exhaust leak on the driver's side crossover tube. One of the bolts backed out a little. Barely audible. Tightened it up and now I can brake torque to at least 6 psi, after that the rear tires break loose anyway, so now it gets out of the hole just fine. Still need a shift kit and a trans cooler at least though to help the trans live.
