backfire problem, please help

[jazzmaster218]

Hey I just purchased a 1987 Buick Regal Turbo T. I'm the second owner of the car, which has 81k miles on it. All original except for the exhaust, which is a flowmaster, and an aftermarket chip. I seem to be having a problem with a backfire though. It's very irregular though because it only happens after the car has been started and ran numerous times during the day, say about 4 to 6. The car will run amazingly for the first 3 starts but then it starts to act up. It studders like it wants to stall after being hard on the turbo and then off, it then tends to backfire and stall out. Does anyone know what could be the cause of this? The turbo spools up and boosts fine. I know there is an aftermarket chip in there, but that's it. Please help me out, I really want this car to run well, it's an amazing automobile.

 

[chris j. 87gn]

first, try not to "slam the door" on the turbo, it's not a good thing! back fire thru the intake or exhaust? smoke? need more info... you need to get/have or borrow...scanmaster, direct scan or some scanner to see whats going on.. fuel pressure gauge,prefferably one you can see while driving to see what the press. is doing when event occurs. all of this you probably already know but with out it your flying blind. post more info!

 

[jazzmaster218]

back fire through the exhaust,a little smoke out the tail pipe when it happens. Then it stalls out. I'm not a mechanic and don't know much about this kinda thing, I'm just looking for advice to give my mechanic who can't seem to figure out what's wrong with it. It was throwing a cam sensor failure code but we replaced the cam sensor, and now we're out of ideas.

 

[ES1]

Where are you located?
Maybe a member can scan it.

 

[jazzmaster218]

i'm located in West Islip NY, which is in Suffolk County on Long Island

 

[TurboGN]

Most check the coil, under load, first. Then the coil module. Then the ESC. However, any gremlin can cause such symptoms, e.g., gauge light (or any wire) paddled into the ECM fuse for hot. If your mechanic isn't pulling scan readings then you may consider finding another one. These bufords are very unique to trouble shoot. Please let us know when you find it. Best of luck.

 

[rob86gn]

how much boost are you running? Does the car have a boost gauge? If it's set too high it could be a backfilre from a lean fuel mixture and too much boost. That's a recipe for disaster.

 

[jazzmaster218]

the car boosts all the way up to the red..I don't know what number that is but it goes all the way up. It has an aftermarket chip so it may be running higher boost than normal. I have the original chip and would put it in this second if you think that could solve the problem. The performance is good enough stock for me.

 

[chris j. 87gn]

ok my friend....don't let me discourage you but...the pretty tach. colors and the pretty boost colors are tied into the same unit, assuming you have no aftermarket boost gauge... get ahold of caspers electronics and have it re cal.ed...(maybe $80.00,not sure!) till then i assure you it is no where near accurate with the corrosion and all! your mechanic should/better have a scanner of some sort to, like turbogn said,see what is going on,or you may need to find a different mechanic. those turbo link numbers... i looked into that setup... post what it tells you so i/and more importantly all the others with more experiece can see them and help you with what it shows...i have been thru the backfire thru the intake or the exhaust, i will look into what causes them, i forgot but i had it told to me once what they "may" mean! sorry but i have had a number of probs myself to remember,you'd think i would but i am getting old!...also... turbogn is correct in saying have you ohm'ed or tested the coil paks...however unless you have the caspers tool( i hear there is a way with clear PVC but it doesn't put a load on the paks) to do so, and i do not, it is hard to say good or bad, why(?)(heat &electronics don't play well together!)... i tested my paks and all were good(good=11-13ohm), i also ran it till hot and all tested good again while "hot", but that hot doesn't work(again mine tested good while "hot")... my coil paks were shot, and after replacing them(along with a new module((under paks))) ,problem solved, if you have a friend who had a turbo t or gn try his/hers to see if they work right , if not, you are in my boat, no one to help you out! another thing is the grounds, the biggest problem would be behind the pass. side head, make sure it is not oil saturated and all is functioning well. i had this problem! made a big difference after i corrected this. remember this thing is 18. did you borrow that fuel press. gauge or have your mech. hook one up? if not do so! if so, make damn sure it can be seen while driving to make sure it works accordingly with the boost...every pound of boost increase means it should also increase one PSI!! if not you have a prob! after re-reading this i may have you mixed up with a diferrent post but all the same still apply, sorry if i did so, but like i said it still applies to your condition! let us know what you see/find!

 

[chris j. 87gn]

like i said sorry about mixing this up but have a look a "70-71-72"'s post!

 

[jazzmaster218]

well i took it to the local buick dealer and luckily it backfired and stalled when they had it and they figured out and fixed the problem...turned out to be burnt ignition wires and coils...not something i would've thought of...car's running great now and thanks for the help.