pa.kevin1

Hello, first post.

1989 Olds Delta 88
81,000 Miles

Let me start by saying there is NO ENGINE LIGHT ON.



Originally the car was (to what I thought) transitioning weird. I had an experienced mechanic drive it around the block and he said it was misfiring, not the tranny. This made tons of sense because the car has been babied its entire life. I could get the car from point A to point B, but it had a rough idle, and it felt like it was skipping gears when accelerating.

Fast forward to attempting to fix it.
Bought new plugs & wires (and am glad I did because I almost bit the bullet and bought a coil pack and ignition control module)

Replaced the plugs and wires, the old plugs were badly corroded. Started the car up, perfect idle. The car was as quiet as a baby at idle, no more shaking. Then I let it warm up for the hell of it before testing it, and upon throwing it into reverse, it wanted to stall out. The problem under load was now worse than before. When hitting the gas in drive or reverse it was missing worse and only wanted to stay in first gear.

After scratching our heads we decided to check the MAF (mass air flow sensor). We disconnected it, and it ran fine. Still idles great, and I drove it around the block multiple times, not a single misfire. Problem solved, right? I went and got a new one, let the battery off for 30 minutes to reset the computer. Upon starting it with the new MAF connected, problem was the same. I thought, did I get a dud or is it something else?

Called the parts placed and arranged to swap out the new one for another new one the next morning. I replaced it once again with another new one, and the same problem. However this time, after I let the car warm up, it drives fine. But if the engines cold it still wants to misfire.


I am at a loss here. The parts I am worried about in order are, fuel pump, fuel filter (afraid to touch fuel filter as lines may break), EGR valve, vacuum lines (we couldn't hear a leak, haven't done the old brake cleaner trick yet), a thermostat sensor, coilpack & module, or the computer. I don't think its the computer as when the MAF is disconnected the engine light comes on.

As a side note, for the past year or so, after sitting for about 6-12 hours it does not want to start. The starter is in decent condition but you have to keep starting and starting or tap the gas a little to get it started. This is what draws me toward fuel pump.

We're at a loss here. Definitely do not want to start wasting money on parts that may or may not fix it. Any and all help is appreciated. Thank you!!!

jaunty75

I'm no expert on the '89s, but I think you've nailed the problem right here. I'm not saying it's the fuel filter. I'm saying it's this attitude. How can you declare that investigating a certain thing as part of the troubleshooting process is off limits because doing so might damage another part? You might as well give up on car repair and go take up needlepoint.

If the fuel lines get damaged, so be it. That suggests that they needed replacing, anyway, and should be replaced. The fuel filter is probably one of the first things to check on a problem like this. They're inexpensive on this car (less than $10), and it probably should be replaced as a matter of course, especially if you don't know how long it's been since it was last replaced if it ever has been.

By the way, what does your experienced mechanic say about this? Is he brave enough to replace the fuel filter?


Welcome to Classicolds. Let's see some photos of this thing.

oldsguybry

Like Jaunty said , don't be afraid to start wrenching on the car . I've learned a great deal since I joined this site and had a lot of trial and error with my car . I have tons of work in front of me yet , but I'm hoping to post some progress I've been making on my car pretty soon .

pa.kevin1

My mechanic is licensed but hasn't been working on cars daily for over 30 years. Hes capable but hesitant in replacing it as he doesn't want it to snowball. Same with dropping the fuel tank, only that obviously will be much more of a process.

I guess I'll start with fuel filter, although I still think a vacuum leak or thermostat sensor could be bad.

I also read something somewhere else about EGR valves having cold and hot modes, does anyone know if this is true?

Also, this car is my daily driver at the moment until I get mine back.


Thanks

jaunty75

I'm not saying you HAVE to replace the fuel filter right now or ever. But that comment you made raised all kinds of alarm bells because it sounds like you're not going to approach the problem intelligently, but rather will do what we see too often on here, and that is people replacing parts *****-nilly because it's easy to do and they hope they'll replace the part that actually needed replacing in the process. In the meantime, they'll have spent lots of money on parts that didn't need to be replaced.

In your case, approach the problem systematically. Start with the most likely source of the problem and work from there. If you or your mechanic eventually get to the point in the process that suggests the fuel filter is a possible culprit, then suck it up, get a wrench, and remove it. I assure you that Oldsmobile did not design the fuel system in such a way that other parts would be damaged in the process of replacing a wear part such as the fuel filter. If removing yours would damage something else, then you have another, equally serious problem to address. This is true for any repair you might need to make.

This car being your daily driver (which you didn't mention initially) does possibly make a difference in that you can't be without it for any significant length of time. So that makes a proper troubleshooting process all the more imperative. But it's important to remember that living with a nearly 30-year-old car as your daily driver carries risks. Parts may have to be ordered and could take days or a week to arrive. You might have difficultly finding a mechanic knowledgeable enough about cars of this vintage that you have confidence in them, etc. Basically, if you're not already pretty confident with a wrench yourself, using a car this old as your daily driver is not recommended. There's always something that needs maintenance. For those of us who see these cars as a hobby, that's the whole point. We fix them ourselves no matter how long it takes because that's where the fun is and because there is no time pressure to do so, and if the car is off the road for days, weeks, or months, it's no problem.

pa.kevin1

This is why I did not immediately change the fuel filter. The lines will most likely break because I live in a humid climate where the entire under body is rusted except for where the undercoat covers. However the new plugs and wires allowed the car to idle smooth, unlike before when the entire engine would shake in park. Also, the car was incapable of being driven (after the new plugs & wires) until the new MAF was installed. I haven't wasted money yet, and I am trying to fix things in order of importance. I suppose the next thing I will do is replace the fuel filter and most likely lines as well. Hoping this will allow clean cold starts and fix the misfire.

$35 between plugs and wires
$120 MAF sensor with commercial discount

I made this post is because I knew for a car to only misfire cold would be uncommon, and was hoping maybe someone else has came across this problem.

Thanks