87. fuel filter location? weird problems. surging

[thefish]

First, can anybody tell me where the fuel filter is on this car, 87 bonneville?

Now, for the problems. Cold start: no problem. Starts and runs strong. Warmed up: crank, crank, crank and nothing. Usually after letting it cool down (seems like about <120 degrees) it starts right up like nothing was ever wrong.

Next, I've had this car for about a year. It has about 160,000 miles on it and on a few occasions in that time I've started it and the engine surges - driving or parked. WHEN it's doing this, it will surge between about 800 and 2000 rpm immediately after startup while 'idling'. After several minutes it tends to mellow out and, while still fluctuating, hang around 1000 (which is where it idles when no problems are occuring). If I then give it gas it will either die or run rough around 1000 rpm until I'm giving it enough gas to get the engine speed above 2000 rpm. In the latter case, it jumps quickly to about 2000 or more. Also if I hold the gas pedal down any amount that gets it above idle, after surging upward in speed, the engine gradually runs slower and slower until it's no longer running. This is while holding the accelerator in one position, not letting up. When it dies it generally starts right back up, but still runs as before.

I haven't figured out when it will or won't do this; and when it doesn't, it runs flawlessly.

Hope to hear from you,
F

[Stylin 89]

Look for the fuel filter in front of the gas tank on the driver side. It also could be the pump, but the filter is cheaper to replace and may fix the problem.

[randman1]

I agree with the fuel filter idea but use caution when you remove the old one. Corrosion protection on the fuel and brake lines must not have been high on the priority list when the car was manufacturered. As I touched the lines on my 90, they crumbled. The end result was a new fuel sending unit ($118), 20" section of replacement fiel line ($20), and some very hard to find replacement brake lines and components.

Your idle problem might be caused by the Idle Air Controller (IAC). When the car is idling, the throttle body butterfly is nearly completely closed. In order to maintain a steady idle, the ECM tells the IAC to open or close. When the IAC is all crudded up, it can't move in and out as fast as the ECM can tell it to causing rough idle and sometimes stalling. This is known unofficially as a "gunked-up IAC".

The best solution is to remove the whole throttle body assembly, remove the 3 sensors (TPS, IAC and MAF (use extreme care when removing and don't get any TB cleaner in the MAF sensor)), and spray the hell out of the TB with STP Throttle Body and Intake Cleaner. You will probably find quite a bit of funky stuff on the back side of the butterfly and in the IAC opening. More than likely, you'll have to use a brush along with the cleaner to get all of it out. Spray the cleaner on the IAC valve too but do not adjust it by pulling, pushing or screwing on the end. Reinstall the sensors then reinstall the assembly.

[DAVE K]

iwas reading what randman1 was saying about the
[iac]would this apply to a 1985 parisiene 305 4bbl?
sounds very much like my problem!esp.after reading what the fish said.

[randman1]

Originally Posted by DAVE K

iwas reading what randman1 was saying about the
[iac]would this apply to a 1985 parisiene 305 4bbl?
sounds very much like my problem!esp.after reading what the fish said.

No this would not apply for your suituation. Carbs function rather differently than the computer controled throttle body. You do not have an IAC.

It still could be due to gunk build-up. That's why they make carb cleaner . I'm by no means a carb expert so unfortunately I can not give you any further details an troubleshooting your specific problem.

[Stylin 89]

Sorry about you luck. When I changed my fuel filter I didn't run into those types of problems. Thank you for letting me know brake lines are hard to fine. I'll keep an eye out.

Originally Posted by randman1

I agree with the fuel filter idea but use caution when you remove the old one. Corrosion protection on the fuel and brake lines must not have been high on the priority list when the car was manufacturered. As I touched the lines on my 90, they crumbled. The end result was a new fuel sending unit ($118), 20" section of replacement fiel line ($20), and some very hard to find replacement brake lines and components.

Your idle problem might be caused by the Idle Air Controller (IAC). When the car is idling, the throttle body butterfly is nearly completely closed. In order to maintain a steady idle, the ECM tells the IAC to open or close. When the IAC is all crudded up, it can't move in and out as fast as the ECM can tell it to causing rough idle and sometimes stalling. This is known unofficially as a "gunked-up IAC".

The best solution is to remove the whole throttle body assembly, remove the 3 sensors (TPS, IAC and MAF (use extreme care when removing and don't get any TB cleaner in the MAF sensor)), and spray the hell out of the TB with STP Throttle Body and Intake Cleaner. You will probably find quite a bit of funky stuff on the back side of the butterfly and in the IAC opening. More than likely, you'll have to use a brush along with the cleaner to get all of it out. Spray the cleaner on the IAC valve too but do not adjust it by pulling, pushing or screwing on the end. Reinstall the sensors then reinstall the assembly.

[randman1]

Originally Posted by Stylin 89

Thank you for letting me know brake lines are hard to fine. I'll keep an eye out.

I have that damn Teves ABS brake system. The line from the MC to the rear proportioner valve was 6mm diameter instead of 1/4'", the nut was some bizzare metric diameter, thread count and length and it needed a bubble flare instead of a double flare. Nobody in the USA carried such a thing. I finally found them on the web from a Canadian manufacturer. Problem was, they only sell their products to retail stores or repair shops primarily in Canada. The general manager understood my agony and sent 2 20" lines for no charge. I couldnt believe it.

The other lines were available but you have to look in the "import" section at the parts store cause again they are metric nuts and bubble flares.

[thefish]

I actually fixed my '87 before I ever got a reply here. You weren't kidding about corroded fuel lines however. Mine broke the moment I began putting slight pressure on it to remove the fuel filter. All the surging and tempermental problems were being caused by the mass air flow sensor. Another board led me to believe it was the TPS, but I was able to test it and find out it was fine. I realized that the car ran better - although not well at all - with the MAF unplugged than with its plug connected so I went ahead and bought one. That did it. Not a cheap part but it was worth the 50 bucks to put an end to so many problems. I'd always had older cars before I got this one. They do the same thing, drive, without all this electronic crap. Seems like all these sensors and other do-wackys are just something else to go wrong.

[randman1]

I'm glad you found the problem. Did you try to clean the MAF before replacing it? Just wondering cause it is basically a solid state electronic component. Usually these types of components either work or they don't. Not too many intermittent issues

$50 bucks is not too bad for a MAF sensor either