1986 Olds Delta 88 running rough

[RobertS]

List,

I'm new to the list, so first let me intoduce myself.

My name is Robert, and this is a new car to me.

It has all of the maintenance records and is in very good shape inside and

out.

I just had the tranny worked on and has had a new TQ placed last week. The

car has been sitting for about 6 months waiting for the funds to have the TQ

replaced.

Now I need to take are of a rough running problem.

I plan on doing a minor tune-up (plugs and wires), fuel injector cleaner.

I thought I would replace the cap and rotor, but found out that this

particular engine has no cap and rotor.

Plug wires come directly from the coil, correct?

Anyways what else do I need to look forward to?

Since the car sat for 6 months with only being started once a week and

driven acouple of miles each time, I'm also thinking that maybe condensation

in the fuel and possibly a new fuel filter.

Anyways, any help would be appreciated.

Thanks,

Robert

[86 2dr.ltd]

Sorry this is a old post now. I dont check in here much lately. You must have the FWD w/3.0 or 3.8 Buick V6 right ? Anyhow thats called the coil pack, underneath of it is called the ignition module. All that stuff became computer controlled in 86. A great system really.

Plugs and wires first. Thing is there are so many variables that cause running problems with these sensor/computor controlled spark/timing,injector/timing fuel mixture systems. Many have fixed similar problems with different parts.

If the timing chain and gear has not been replaced, you should do it when you have an extra 300.00 sometime down the road. Dont rev the heck out of it. A strechted/wore chain and sprockets give ECM (engine control module)varying signals from the cam and crank sensor. This is one thing that can cause a irregular running and idleing problem. Not a skip like bad wires but a moody running problem. If the chain breaks it can damage valves, just a matter of luck.

Fuel pressure is important.

MAF sensors give a lot of running problems, one is hesitation, another is stalling at idle.

There are so many things I could go on and on. Buy a Haynes Buick, Oldsmobile & Pontiac Full-size models manual. 85 thru ? mine goes through 98. Some reading in the emissions and engine control systems chapter as well as the engine electrical systems chapter will make quick sense of how all these sensors sending signals to the ECM makes the engines run so effeciently and also how when one of these sensors fails runs so poorly.

Best thing I believe is a good trust worthy diagonostics man that understands the Buick V6 well. I have one localy.

Heres a few sites I visit frequently the Bonneville site people will welcome you best and try to help when they can. Use the "Other H body" or "87-91" boards. The LeSabre T-type guys usually ignore outsiders whose cars dont measure up to their "package". Its the same car just a few cosmetics and heavy suspension. Good informative reading (sometimes).

http://www.bonnevilleclub.com/forum/ Im Steve LS on this one.

http://www.lesabret.com/

Your 86 engine is just slightly different than the 87 engine and very little difference even if you have the 3.0. The engine changed again in 88 but all functions were still basicly the same.

[Guest]

You most likely have the 3800 engine. problem with these motors is the harmonic...it has 2 sets of concentric rings that control the ign...when the harmonic fails (the rubber goes out) it can produce the rough running.

Put the motor on a scanner and look for the following:

TPS idle voltage out of range - a fixed value will be used and the map will be used to change fuel delivery

MAF sensor out of range...a quick look is to bang the MAF lightly with a rubber mallet while it is idling - if the idle changes the MAF is bad. (I have a used one in stock, new ones are $120-150)

4 line vacuum port on top if the intake leaking....the molded nitrile rubber stretches with age and big leaks develop.

Bad cam sensor or crank sensor/reluctor (as noted before)

Bad EGR valve/solenoid pack

Once you scan the motor you can proceed from there.

I have an entire 1990 powertrain for sale from a 98 regency - see the buy/sell page