Gentlemen, need some thoughts/solutions. My 87 Limited T just started to buck and cough and surge a little at WOT after I changed plugs from 42's to 44's, new PCV valve, new Idle Air valve and new grommet in valve cover breather. I am running 20lbs boost with 42lb injectors and stock fuel pump and a Lebonte alky kit, which I love. Car ran great before these changes and still does till you start getting into it. Maybe it's a coincidence that this stated happening and has nothing to do with my "Tune Up" ??? Any thoughts in general? What are potential causes? This is just a street car and not a serious racer. Has some other mods such a s t60 turbo, 3 inch down pipe, Red Armstrong 93 chip, etc. but nothing radical. Engine internals are stock, 96K on the clock. Like I said, car ran great before I made these changes. Thanks....
WOT Bucking Problem
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Check the maf pipe. Make sure no leaks between the maf and turbo.
Red Regal T
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Sounds like your ignition module or the coilpak is going south.
Thanks for the replies so far, but I was just thinking, I used a generic PCV valve that I had laying around. It was new and seemed identical to the Delco one I replaced, but had no part number or manufacturer on it. Could this be an issue? Is the turbo Buick PCV valve unique in some way? Maybe I'm losing boost or something? Thanks
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One thing you do not mention is your fuel pressure? 
Do you know anything about the fuel pump - new, old, ever replaced?
You now have larger injectors and a LOT more boost than stock, and know nothing about fuel delivery/pressure?
Start with a fuel pressure gauge that you can view when you are driving, and be sure pressure tracks from 45 psi to 65 psi when at 20 psi boost.
After a few WOT runs with it "bucking", internal damage to the engine is very possible.
With the alchy system, if you do not have ample fuel delivery with the increased HP level, it will quickly cause damage.
It is possible you have an ignition problem, but you need to verify fuel delivery first. No spark at high RPM is not good, but no, or not enough fuel will be expensive.
Do you know anything about the fuel pump - new, old, ever replaced?
You now have larger injectors and a LOT more boost than stock, and know nothing about fuel delivery/pressure?
Start with a fuel pressure gauge that you can view when you are driving, and be sure pressure tracks from 45 psi to 65 psi when at 20 psi boost.
After a few WOT runs with it "bucking", internal damage to the engine is very possible.
With the alchy system, if you do not have ample fuel delivery with the increased HP level, it will quickly cause damage.
It is possible you have an ignition problem, but you need to verify fuel delivery first. No spark at high RPM is not good, but no, or not enough fuel will be expensive.
Thanks, Nick. Unfortunately I have no knowledge of the fuel pump situation, only owned the car for a little over a year. The tank, however, looks like it's never been dropped based on the condition of the straps, etc. I have a fuel pressure gauge under the hood that maybe I can somehow extend into the driver's compartment. At Idle, the gauge hangs around 42 lbs and gooses up past 50lbs when you move the throttle under the hood, but then it seems to drop back down. Not sure what it looks like as boost climbs...One thing you do not mention is your fuel pressure?
Do you know anything about the fuel pump - new, old, ever replaced?
You now have larger injectors and a LOT more boost than stock, and know nothing about fuel delivery/pressure?
Start with a fuel pressure gauge that you can view when you are driving, and be sure pressure tracks from 45 psi to 65 psi when at 20 psi boost.
After a few WOT runs with it "bucking", internal damage to the engine is very possible.
With the alchy system, if you do not have ample fuel delivery with the increased HP level, it will quickly cause damage.
It is possible you have an ignition problem, but you need to verify fuel delivery first. No spark at high RPM is not good, but no, or not enough fuel will be expensive.
berserker6
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Start with the easy stuff. did you check the gaps on the plugs? Double check that the plug wires are all connected properly. If you have a scanmaster are you seeing anything out of order? Like AF numbers.
CaptainInsane-O
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Gentlemen, need some thoughts/solutions. My 87 Limited T just started to buck and cough and surge a little at WOT after I changed plugs from 42's to 44's, new PCV valve, new Idle Air valve and new grommet in valve cover breather. I am running 20lbs boost with 42lb injectors andstock fuel pump
That fuel pump is a time bomb waiting to grenade your motor!!!
Generic PCV could be contributing... do you have a scan tool?
I have an OTC advanced model scan tool that I will hook up. Anything in particular to look for? Sitting in park idling? Driving? Thanks...
You should be looking at your 02 readings while under heavy acceleration to see how your fueling is. There is no way I'd recommend driving the car with a stock fuel pump that can barely keep up with stock requirements. 
You are asking a lot out of that little guy with those injectors and boost levels. Just post some total readings from your scan tool.
You are asking a lot out of that little guy with those injectors and boost levels. Just post some total readings from your scan tool.CaptainInsane-O
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Here's a guideline for what numbers you should see on the scan tool:
Quick Reference Page For the '86/'87 Turbo Regals and '89 Turbo T/A
I'd STRONGLY recommend backing way down on the boost before going WOT with that pump in there again.
Quick Reference Page For the '86/'87 Turbo Regals and '89 Turbo T/A
I'd STRONGLY recommend backing way down on the boost before going WOT with that pump in there again.
Thanks, let me check out some readings and see what I've got...You should be looking at your 02 readings while under heavy acceleration to see how your fueling is. There is no way I'd recommend driving the car with a stock fuel pump that can barely keep up with stock requirements.
If I need to replace the fuel pump what would be the best choice for this car? Thanks...You should be looking at your 02 readings while under heavy acceleration to see how your fueling is. There is no way I'd recommend driving the car with a stock fuel pump that can barely keep up with stock requirements.
Hi, just ran some number from my OTC 4000 scanner. These are at idle (750-775 RPM in Park), no time to drive it tonite:
02 Voltage 47-68
02 Cross counts 14-40
TPS 40
MAF 4
INT 118-136
BLM 155-158
LV8 31
IAC 41 cold, 24 hot
MAT 031 C
EGR 50%
Fuel Pressure, 233 stock regulator "Static" 49psi, (41psi w/Vacuum line attached)
Spark plugs are new 44TS at .045 gap (changed from 42TS, same gap)
New generic PCV valve
What's puzzling is that the car ran strong with 20lbs boost before I changed the plugs and PCV valve. Couple more things as I try to reconstruct all this. Car ran strong for a few blasts right after I changed these things but only got up to 18lbs, not 20 like before. Then it started bucking after a few more blasts and I found a a plug wire was not completely seated. I secured the plug wire and it now runs great up untill higher boost. Could that plug be acting up under load now? Or other plugs because of increased heat range? I raised the heat range because the owners manual calls for the 44 plug at .045 gap, no other reason. Thank you for any thoughts or ideas.
Red Regal T
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Red Regal T
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If you borrow another coilpak/ignition module combination, it only takes five minutes to install it on your car and try it out. If your car accelerates at WOT smoothly, then your unit is the problem.
Might be your plug gap too. Gap them down around .032 and try it.
Are you running alcohol? What are you doing to run 20 lbs of boost?
Might be your plug gap too. Gap them down around .032 and try it.
Are you running alcohol? What are you doing to run 20 lbs of boost?
John, thanks for the advice. I am running the LaBonte ISG-25 alky system. Installed it about a week ago and all was fine until my "Tune Up". This alky system is perfect for what I need and is well made...no knock at all at 20lbs with a Red Armstrong 93 chip and 93 octane. Thx, Ken
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