Downpipe problems

kjhansen

Member
Joined
May 26, 2001
The car is a 1987 Turbo Regal. Mods include:
Precision PT5858 turbo with an adjustable wastegate actuator
TA headers and cross pipe
TA 3" downpipe with internal wastegate and O2 sensor bung
3" MAF pipe/Delphi LT1 MAF sensor /Translator and K&N filter
70mm intake with RJC Powerplate
Racetronics hi-flow 255 fuel pump
Caspers Volt Booster and Hotwire kit
Kirban adjustable FPR
Turbo Tweak 42lb injectors and Turbo Tweak 57 chip
AlkyControl alcohol injection kit
and basically whole lot of other stuff including trans, axles, gauges, frame stiffening etc., etc., etc.

The car ran great, other than hitting 30psi of boost, or more, a couple of times right after I got it and before I figured out what was going on. At 30psi of boost it was very very quick, I have to admit. Even driving below 30psi the car had a lot of power and would spin the tires at 30 mph. This was back in September. I've been driving it since then without any problems, just not above 20psi of boost. I couldn't adjust the boost as you will see, but I could adjust my foot's pressure on the gas pedal. But it was bugging me. I like things to work right.

I discovered that the problem was that the wastegate was stuck in the closed position, meaning boost was not limited. I tried working the external lever back and forth but it would not budge.
My solution was to get a new 3" downpipe with internal wastegate just like the old one, thus avoiding any possible problems with fixing the old wastegate. So I got a 3" downpipe from RJC Racing.

Now, I've been working on Turbo Regals for a long time, so I'm not a newbie. Not an expert but not new to it either. But I'm now 72 years old and my back is really bad. Lying down under a car is very difficult. So after I got the downpipe from RJC I took the car to a local muffler shop and asked them to install the new downpipe. Seemed simple enough.

Multiple problems ensued.

First, the mechanic couldn't get the old one off cleanly and broke a hex-head wrench.
Second, then he broke off the bolt that had broken the hex head wrench.
Third he broke two other bolts. Three out of four.

So when he finally got the downpipe off, he cleaned out the threads and put studs in the turbo. Then he tried to install the new downpipe and it WOULD NOT FIT down to the test pipe. He tried and tried, but it contacted several points on the way down (the passenger-side rear upper A-Arm bushing and the plastic inner fender) and then had too steep an angle to attach the test pipe and line it up with the exhaust. So he called me, explained the situation. I authorized him to reinstall the old pipe. Rats.

Well it was about to get worse.

He finally got the old pipe back in and called me late Friday after business hours and asked me to come get my car. At this point he told me that he had managed to loosen up the wastegate puck and that I should have boost control now. When I picked it up, he locked up and left for the weekend.

I drove out the driveway and immediately noticed that the car had no power, stalled and stuttered just driving on city streets at any speed. On the country roads out to my house it shifted into 4th gear above 45 mph, but stuttered and lugged jerkily when the torque converter clutch engaged.

It was too late to do anything with it, as I had a date with my wife. We went in her car. The next morning I went out and checked under the hood. The number 4 spark plug wire had come off. So I reconnected that and test drove the car. It ran smoothly when boost was low, but didn't have much power. Under WOT it was flat and weak and then BACKFIRED when shifting into 3rd gear!

FYI, while I have a ScanMaster that's the only data reader I have. No data logger. I had TurboLink and WIN ALDL when I had my other Turbo Regal back in 1996-2009, but those went with the car. I tried the new WIN ALDL but all it did was mess up my ECM. So I can't provide a data stream.

Has anybody had any experience with this kind of thing? My best guess is he messed up reinstalling the old downpipe somehow. But how?

Also, if you know any good TR mechanics around Springfield, Missouri (I actually live in Lebanon, Missouri, about 50 miles east of Springfield), please let me know. So far every mechanic that has touched this car has left it worse than when they found it.

Keith
 

John Larkin

Sublime Master of Turbology
Joined
May 25, 2001
Backfire is an indication of rich air/fuel ratio. Do you think you can wrestle the downpipe back out? That would be best, studs sound like a problem to work around and get the downpipe lined up. You basically "unscrew/twist" it out of the side of the engine bay. Just to be sure I am clear, are the downpipe holes fixed and threaded properly? I would pull the plugs on that side of the engine and make sure none are cracked on the porcelein. Also note the color of the insulator and the electrode for any soot or deposits.

TR mechanics in MO I am not familiar with any. I think you still have a sticking wastegate arm or the puck is getting cocked.
 

TurboBuRick

Moderator
Staff member
Joined
Feb 18, 2006
Who knows what happened to the car but it’s always best to find someone who specializes in the turbo Buick’s. These cars can be very challenging. It takes a experienced turbo Buick mechanic to diagnose and fix correctly.
Unfortunately there are not a lot of those around anymore.
I’m in Chicago south burbs. I fix a lot of Buick’s that come from other mechanics that could never seem to fix but I am pretty far from you.
hopefully someone will chime in with a closer option.
 

kjhansen

Member
Joined
May 26, 2001
Who knows what happened to the car but it’s always best to find someone who specializes in the turbo Buick’s. These cars can be very challenging. It takes a experienced turbo Buick mechanic to diagnose and fix correctly.
Unfortunately there are not a lot of those around anymore.
I’m in Chicago south burbs. I fix a lot of Buick’s that come from other mechanics that could never seem to fix but I am pretty far from you.
hopefully someone will chime in with a closer option.
Backfire is an indication of rich air/fuel ratio. Do you think you can wrestle the downpipe back out? That would be best, studs sound like a problem to work around and get the downpipe lined up. You basically "unscrew/twist" it out of the side of the engine bay. Just to be sure I am clear, are the downpipe holes fixed and threaded properly? I would pull the plugs on that side of the engine and make sure none are cracked on the porcelein. Also note the color of the insulator and the electrode for any soot or deposits.

TR mechanics in MO I am not familiar with any. I think you still have a sticking wastegate arm or the puck is getting cocked.
I'm still stumped. I did replace the TPS this morning because it wouldn't hold a reading--that's been going on for months though. It wouldn't stay put on the low end. I'd set it in the .40 to .42 range and by the end of the day it would be at .44 to .46. I don't know how that would affect the car's acceleration etc., but it does idle a bit better. .

But... I'm thinking it might be some kind of electrical/ignition problem in addition to the stuck wastegate. Reason is that in 4th gear and torque converter lock-up on a straight, flat road, I get a stutter that feels like a miss. Just cruising, no boost. When the torque converter isn't locked, the expected standard torque converter slippage smooths out the "miss." The miss is new by the way. Didn't do it before this mess started. It's a mess miss.

I reduced alcohol injection level because of the lower boost, and that has stopped the backfire on the 2-3 shift and smoothed out the flat spot in 2nd gear. Still only 7psi of boost.

I checked the passenger side spark plugs and they looked great. There was one spark plug wire loose on the passenger's side and one loose on the driver's side (not counting the one that was completely disconnected). The connections were contacting the plug tops, they just were not on tight. I pushed them on and got a solid click. There feels like a minor improvement in drivability, but it's still not running much boost. Seven psi max, and it's still got a slight miss at cruising speeds—which means at all speeds, it’s just not noticeable until the TC locks.

Oddly, I shut the hood when the engine was running and it stalled. I immediately thought "bad connection a the battery, or somewhere" but the battery connections are tight. It has a Delphi LT1 MAF sensor/Translator, which isn't mounted high enough to get hit by the hood, but I'll check the connections. There is no aftermarket stereo installed, just the stock unit, so no additional wiring at the battery posts. It does have a TPS/TEC box and a Casper's volt booster.

I was concerned that the disconnected spark plug wire might have caused the walls in the #4 cylinder to wash out and cause gasoline contamination of the oil, so I did the old sniffer test (although I didn't do a taste test. Yech). Smelled like oil. Oddly though, the oil is pretty black and it's only been a few hundred miles since an oil change with pure synthetic... and the zinc additive.

I did ohm out the coil packs. The passenger side tower that has the #4 and #1 plugs on it ohmed at 11.6 or thereabouts. The #4 plug was the one that was disconnected completely. The other two towers ohmed in the low 12s. I found what looks like a brand new coil pack and ignition module in the spare parts I got with the car and it ohmed out pretty much the same, but I think I'll try putting it on tomorrow morning. Something's causing this miss.

As far as the boost is concerned I think I'm going to have to fix (get fixed--I don't have the facilities to fix it) the downpipe I have. So far I have $800 in this new downpipe and it still doesn't fit... $500 for the downpipe and $300 total in labor trying to get it to fit. RJC Racing doesn't seem real interested in me returning it, but I haven't pushed them very hard. Anybody want to buy a brand new RJC racing downpipe with the O2 sensor bung already installed? $500 new, I'll let you have it for $400 plus shipping obo. RJC swears it will fit any stock-style headers. Anybody know a shop that will repair an existing wastegate on a generic downpipe? The receipt I have for it is dated 2011 and is from Kirban Performance. They have no records showing who their supplier was in 2011, no surprise.
 

MikeS

Active Member
Joined
Oct 30, 2012
You mention it was hitting 30psi, was it tuned for roughly that much boost? In the second post you said it was hitting only 7psi, was that total at WOT? That would be a significant difference in fueling between those two and could cause some of the issues you described. Are you using a scanmaster to watch 02 millivolts, or a wideband? It sounds like you went from a situation where the wastegate was not opening to a wastegate that is not closing and now bleeding off exhaust pressure prematurely.

As far as the downpipe, I've had to cut and re-shape mine to make it fit perfectly. Maybe check around for a local fabricator that builds turbo system hot sides (i.e. not a generic muffler shop). I'd get the downpipe issue fixed before you start chasing electrical or other problems, that's where this all started.
 

Slow91z

Turbobuick.com Helper
Staff member
Joined
Aug 7, 2003
Sounds like the wastegate is hung open now, the low boost is causing a rich condition under throttle causing the backfire and general lack of spunk...start by checking the adjustment on the wastegate, it could be holding it open if the guy just threaded it way out.
 

kjhansen

Member
Joined
May 26, 2001
The wastegate was hung open as you both said. And no, the tune was not for 30psi, it was for 21psi. In any case, the muffler guy had worked the wastegate until it would turn a little, and that's what happened. It had gotten a little turned and then froze in that position--wouldn't go back. I removed and blocked the boost line that pushes the wastegate open and sucks it shut. Now it's running too much boost again, with the wastegate locked shut, but it's running smooth and well and I'm "adjusting" the boost with my right foot until I get the wastegate fixed. Surely Springfield, MO will have a speed shop that does turbo work. Good suggestion. In our town, the word "import" is a dirty word (except for cheap Kias and Hyundais). There isn't a single import car dealer here. You have to drive 50 miles west or 30 miles east if you want to buy an import or get one serviced. People look at me weird because my daily driver is a Toyota Highlander.... Sacrilege.

The electrical problem turned out to be the ignition module or coil pack, as I thought. Not sure which. The previous owner had included a lot of spare parts and, as I previously mentioned, there was a brand new coil pack and ignition module already assembled. Well, that's a pretty easy job, so I braved the afternoon heat and humidity and put it on and that fixed the electronics.

Maybe I'll head over to "Cruisin' Kearney" in Springfield on Saturday and see if I can find some turbo guys. Kearney is a four lane road through Springfield and the city has made it legal to "cruise" there and hang around in parking lots. No burnouts allowed. Sure, yeah, right. I've actually never been (they stay up past my bedtime) but somebody always posts videos of "Cruisin' Kearney" on YouTube.
Good thing I've got cold A/C, 'cause it gets hot and muggy here in the midwest during the summer.
 

John Larkin

Sublime Master of Turbology
Joined
May 25, 2001
The sleeve the wastegate swivels in is obviously hanging. Unfortunately the arm is welded on. But if you take some good photos of how it is assembled, you can grind the weld off, pop off the arm, clearance the swivel a little, and then have the arm welded back on, you would likely be good to go. I think there is a bushing in there, ATR downpipes used to have this problem. It likely only needs a little bit of sanding to get it right or perhaps one drill size larger (meaning .001 or maybe .002), a light touch.
 

kjhansen

Member
Joined
May 26, 2001
Sounds good, but I don't have the tools or skills needed to do that and don't know anybody that does--certainly not the muffler shop that I was using. This is a relatively small town, and it isn't a suburb of a larger town. We're just out here on our own. In any case, I'm going to check in Springfield, MO, which is about 50 miles west of here to see if there's anybody that might be able to fix it. That's the nearest town of any size. It might be an ATR downpipe--it was sold by Kirban in 2011 and they don't have records going back that far to identify who their supplier was, so who knows?
 

Slow91z

Turbobuick.com Helper
Staff member
Joined
Aug 7, 2003
RJC has a kit to fix it instead of replacing the whole pipe. Part number RJC-WGA https://rjcracing.com/product/exhaust-systems-2/flanges-weld-bungs/

You grind the weld off the arm, drive the old one out, installed the new one dime sized weld and done...Any decent welder should be able to handle it, maybe have a decent repair shop pull the downpipe, you take it to a fabrication shop and then have shop reinstall, sounds like the hard part (seized bolts) has been taken care of.
 

kjhansen

Member
Joined
May 26, 2001
Thanks. This is what I'm going to do if I can find someone who can do it. Our weld shop here in town specializes in stuff that's tractor-size... But Springfield, Missouri is just 50 miles away. They must have something. If they don't, Jason at RJC says to send him both pipes, he'll refund me the new pipe and fix the old one. Assuming the new pipe still looks new enough to resell as new.
 

Pronto

You can't knock them up with spit.
Joined
Dec 9, 2002
TA headers have a turbo flange that has slotted bolt holes. The "mechanic" could have loosened them and "clocked" the dp to fit better. We have done that to get the dp to fit right on several cars. Just a little twist can make a big difference at the other end.
 

kjhansen

Member
Joined
May 26, 2001
He said he tried everything. The new downpipe is on its way back to RJC. I'm taking the old one to a custom shop in Springfield (only 60 miles away) to have the wastegate repaired. I known the old one will fit back on.
 
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