Questions and Answers

Buick Regal Over Injecting

Q. Hey I got a tuff problem here. Here are the cars specs.

1988 Buick Regal 120,000 miles
2.8 liter V6 multiport injection
4 speed OD automatic
Power steering
No cruise control
A/C-currently disabled (but functional if charged)
No ABS
Yes rack and pinion

Here is the problem.

About 2 months ago my wife brought the car home running on 4 cyl, HOT! and smoking from underneath(smelled like hot tranny/brake) After preliminary inspection I realized that two spark plugs had been gas fouled. The plugs and wires were seemingly original at least very old. I replaced both the plugs and wires, did a fuel pressure check (ok), compression check 180 within 2-4lb on each cyl. The new plugs and wires seemed to fix everything and I had a nice fat blue spark again.

You should know that the only time through this whole thing there has never been a code set in the computer was by me disconnecting something for troubleshooting purposes. 10 days later the same thing happened again while the wife was running errands in stop and go traffic on lunch. I picked up the car 4 hours later after cleaning the front 3 spark plugs (only one of them seemed fouled) there I drove it home. I had about 3 miles to get it home so I started out on 5 cylinders 2/3 of the way it lost another cyl. again and would not accelerate or down shift I had to manually put it in 2nd gear just to maintain speed without flooring it. I eased it home to look for the cause on the weekend.

Being aware of a common problems with both the computer and platinum plugs(after fouling) And there was no fail code in the computer. I replaced both the computer and plugs once again and the temp sensor. The O2 sensor is relatively difficult to reach so I took it to the shop after the problem came back 4 days later to have them see what they though and they agreed it could be the O2 sensor. They also replaced it and the plugs again. This did not help at all. The problem came right back. Since it seemed not to be the same plugs fouling each time I had resisted changing the coils this time I did just that to no avail. the problem came back in a week.

At this point I was ready to give up and buy another car! In one year we had put on the following parts minus normal maintenance. Gas tank, Fuel pump, sending unit, front struts, front rotors, calipers, 4 tires, rear pads and rotors, all fuel lines, computer, plugs, wires, few relays (A/C), O2 sensor, all three ignition coils, and now we had a real difficult problem. We can't afford a new car really so I have to fix this one.

Knowing that the main symptom was fouled plugs and I have good compression and fuel pressure I chose to replace the only remaining questionable part in the ignition system the ecm. WOW What a difference the car is running great for over a month now!!!

It seems as though there was an intermittent heat failure in the part that everybody says if it's broke the car just won't run. So today we went to get the stuff to convert the A/C to R-134a and a new dryer can and condenser so we spent another $200.00 just for comfort because the condenser has a leak. I am also in the process of replacing the broken front grille and cowl with new parts. I left a bit out to try to keep this fairly brief. Such as troubleshooting steps I took and what other shops said.

On the way home from Pep Boys after over a month of running great the same thing starts again!!!!! I am at my wits end. I have $1200 worth of debt into this car and cannot afford to replace it. PLEASE HELP ME!! I am in a new area with no real support network of car buddies.

Begging for help willing the host a barbecue and or a weekend on the lake in Northern Georgia
Neil

A. Gee Neil, I'll bet Manny, Moe and Jack smile a lot when they see you walk in the door.

The only thing you didn't replace would have been the first thing I would have checked. The injectors. The big clue here is the same two cylinders all the time. They are dumping fuel into the cylinders and fouling the plugs. The computer can check the electrical part of the injectors, the coil inside and the associated wiring. But it has no way to check the mechanical part of them. Gum and carbon can build up inside them and keep the plunger from closing completely and allow fuel to continue shooting out.

When a piece of the gunk gets knocked of, it will run smooth for a while. But it builds up again and causes fuel to dump again. I think at this point they are way past cleaning and should be replaced.