97 LT1 problems

[james78657]

Ok, people. I have been reading forms here for a couple of weeks now and I thought I would share my problems and see if anybody will give me some advice on how to fix my problem. I am pulling up a few codes on my scanner, one is P0151 - O2 sensor low volts (bank 2 sensor 1), the other two are the same things, P0300 - random/multiple cylinder misfire. Ok know that I have put the codes that I'm pulling up now I can get to the point as to what the engine is doing. When I start the car it will fire up to about 1500RPM's but then when it goes back down to idle it will just die, unless you give it fuel then it will stay started as long as you give it gas but when you let it go back down to idle it will just die. Ok people there it is please help me, I am mechanicly inclinded so I can do the work myself but I just cant figure this out. Think you for reading this and leaving a post.

[5.0THIS]

The po300 code typically points to the optispark unit in these cars, although checking the coil and ignition module is worth doing. The po151 can be caused by a bad MAF, or a fueling problem or the sensor itself. I believe there could be other causes for a po151, but that's what comes to mind off the top of my head.

[james78657]

But what about the point of the car not staying started unless your giving it gas?

[TLS_Addict]

How many miles does it have? A clogged fuel filter can cause some issues as well.

5.0 is right, the opti is the main key but also the coil can wig out and cuase some upper rpm issues. Also check your plugs and wires to see what sort of shape they are in.

[james78657]

well think the both of yall, I dont think that it is the coil cause there arent any upper RPM issues, it is just when the car is trying to idle that I am having some problems. The plugs and wires are pretty bad so I think that I will start with them then go to the opti. But is there any way to keep the opti from going out every 50 to 60 thousand miles like I have heard from some other threads? Also I just changed the water pump cause the weap hole went out; fuel pump, and the fuel filter, the fuel pump went out so I went ahead and changed the filter also just to be on the safe side about that.

[flybird]

I agree with the other guys.. Start off cheap, replace the fuel filter. I can guarentee you its whole life of the car, no one has replaced it. also clean the MAF sensor.

[flybird]

Oh just saw that you replaced filter. Then yes, replace plugs, clean MAF sensor and maybe put fuel cleaner in the gas tank to help clean the injections.

Goodluck!

[TLS_Addict]

Yup..............if you plan to keep the car invest in a good opti-spark. You have a later model so I think they are vented, right guys?

[james78657]

ok, what is the MAF sensor and where is it located on the car so I can clean it. Plus what is a good opti that I can buy for the car.

[93TransAm]

It's the large black piece of piping with the plug on the side of it before your throttle body.
I would definitely check to make sure all plugs are secure and all wire boots are secure before replacing them. But if they're shot anyway and shes due for a tuneup go for it. It could be the opti, being you just replaced the water pump you could've gotten fluids in it. But without problems over 3500rpm its hard to say. If you do replace the opti , take the other guys advice and get a good one so you don't waste your money. Once all cylinders are firing you're o2 sensor issue should clear up. if not I would also consider maybe your air/fuel mixture is lean (not enough gas) due to the o2 being bad and not getting enough fuel to fire all cylinders correctly. But checking your plugs deposits will tell you a whole lot about what your internal engine conditions are. Good luck

[5.0THIS]

ok, what is the MAF sensor and where is it located on the car so I can clean it. Plus what is a good opti that I can buy for the car.

From what I'm reading, it sounds like you might be better off paying the 90$ diagnostic fee for a dealer to determine what the problem is. Throwing parts at something can get expensive real quick. You can try the easy things first, but be careful. You need to clean the MAF sensor with a specific spray cleaner, and do not touch any part of it inside the sensor.

[james78657]

so I take it I cant use regular brake cleaner to clean the MAF?

[5.0THIS]

so I take it I cant use regular brake cleaner to clean the MAF?

People do that, but CRC makes a spray cleaner specifically for MAF sensors, that should be available at NAPA or some place similar. If you cant find that I would at least use electrical parts cleaner.

[krese]

there is no way to make an opti last for ever.. if you get 70K out of it you did a good job. it is not the best design in the world but really 70k is a lot of miles for a device that expected to do what the opti does. it is just a shame that the prices never came down on them... stick to delco, don't buy the aftermarket crap or you run the risk of more replacements.

[james78657]

But if the opti goes out then the car wont even start would it, since it took the place of the distributor.

[krese]

as others have stated the signs of the opti's death are stumble/missing at high RPMs. the opti rarely dies completely, it just sort of degrades and does not function 100% which is enough to cause issues at times when it would be required to function at 100% such as high RPM.

[james78657]

ok but I am not having problems at high RPM's, when the car starts and goes up to 1500RPM's then when it goes back down to idel it just dies.

[97RamAirWS6]

I too am having a similar problem. I have a 97 Ram Air pretty much stock other than bolt on parts. Such as stainless Hooker fenderwell headers, Borla exhaust(magnaflow guys calm down) and so on. But I have a 72k mile car with 8.5 msd super conductor wires with the heat wraps intact. Runs beutifully one day, and the next it runs perfect for 2 minutes the engine light comes on and it starts to miss. Any time its cold it runs perfect for 2 minutes then starts to miss. It is a 6spd and it has a hesitation throughout normal range. Believe it or not but I bought the car new and its only been in 6th gear 3 times(because when I shift to 6th at 62 my rpms drop to 1100). I have the p0300 and an oxygen sensor code.

I narrowed it down to the #4 cylinder. I unplugged the injectors one at a time to see if it changed the engine and only the number 4 did( second plug back on passenger side). I unbolted the fuel rail aand swapped injectors, only to see the same problem. From a cold start, the car will run perfectly for about 2 minutes then develop a miss on the number 4 cylinder. Any takers on this one?. New water pump, new. Ac delco opti with 8.5 msd wires, have had months of trouble free driving. What gets me is the code says "random" misfire but it is always the same cylinder dropping off????????

[93TransAm]

It's a very common problem for spark plug wire boots to become slightly loose and cause these problems. On dozens of Occasions I have had customers report problems with missfires and 80% of the time its a spark plug wire boot slightly loose. I always just pop it off, get some pliers and crimp it slightly then oob on some dielectric grease and they're fine. It's especially common on V8's with old motor mounts too. The engine revs twisting the motor slightly and over time loosens wires up. I would just check them all while you're at it. It may beatup your wrist a bit but with tiptoe action and twisting you can get your arm just about anywhere in the engine bay. Don't be scared to force your hand in either unless your trying to get behind the dipstick. I would also take-off you intake and reach under to make sure everything is secure on the opti itself. A little patience goes a long way, all of the above might take you 30 mins. good luck