I was having trouble with several injectors in a 1991 Oldsmobile 3800 engine. A friend had a few injectors from a 1996 3800 Pontiac...........they looked a bit different....they fit....they worked just great (even better). ANY harm done? Thanks.

Other than being larger than your stockers, they are fine. But they are dumping too much fuel into the chamber. The O2 sees that it'* rich, than leaning it out. So then some cylinders (with stock injectors) are lean and the cylinders with new ones are still rich. Get a matched set on there. Preferably with the stock rating, which I think is 21 lb/hr.

I replaced all 6 at the same time.....is this still a problem?

It'* better, but not what it should be. Have you checked your mileage since? The Series II injectors are quite a but higher flowing than your stockers. Your engine "should" adjust to run them at a lower duty cycle, but I'm skeptical as to how far the PCM can adjust in response to the O2 sensor. It may be running hella rich.

He'* loving the extra power though. Mileage isn't such an issue when you get slapped back into the seat

The injectors would only help if you were exceeding your fuel capacity. I doubt it. You got power back but didn't get any you shouldn't already have.

Had to go and say that...meanwhile he was feeling good about it. I was trying to be nice..lol

When I did the work I was at about 1/2 tank. This week I'm on my first full tank and will be able to check the milage to see. By my gauge at this point it appears I'm doing a bit better.....We'll let you know. It does feel better to have a bit quicker peddle response than I've had. This old thing has over 200k on it and it still runs like a top. I've had three 3800 engine cars and my parents have had 2 since 1988......I love the engines.....good, solid, easy to work on..............Just wish GM would do something about the poor transmissions....I had to rebuild this one at 100k. Back to the injectors the old ones were only 4 holers........the newer ones that were given me are 6 holers.............I assumed I'd have a bit higher flow rate. I haven't had time to hook the AutoXray up on it yet to check my values....................That'* the job for this weekend.

Thanks

CAPABLE of more flow, yes. But they won't. Your PCM won't deliver more fuel because your injectors are bigger. It'll still maintain the proper AFR. And if the injectors are RATED too high, causing the PCM to run them at too low of a duty cycle, you could have other problems.

I think I might have begun to have such a problem. This evening as I got home I smelled a heavy fuel smell.....saw no raw fuel leakage. "Sniffed" the problem to the area of the vacuum line from the brake pwer booster to the top of the UIM area. The inlet area appeared a bit loose, but couldn't tighten it any.......there was no gasket there....It seems to me that from earlier work on dad'* car there was a gasket there.....correct?

Thanks