fuel or ignition problem???

[sharky92206]

Hello,
2001 Impala LS 3.8L 80Kmiles Im new around here and thought you guys might be able to help out with this very frustrating problem.
1.Sometimes when I'm driving the car will act like it loses fuel or ignition cuts out, but i will try to keep it running so i pump the gas and in reaction the cars rpm will keep jumping up and down making bog sounds, idle air will open fully.
2.I will be idling then it will shut off, then i will try to start it but doesn't want to. Sometimes it will "back fire" through the intake.

I have changed the IAC, TPS, and fuel filter. I am lost with this problem oh and the check engine light is on

[j cAT]

Originally Posted by sharky92206

Hello,
2001 Impala LS 3.8L 80Kmiles Im new around here and thought you guys might be able to help out with this very frustrating problem.
1.Sometimes when I'm driving the car will act like it loses fuel or ignition cuts out, but i will try to keep it running so i pump the gas and in reaction the cars rpm will keep jumping up and down making bog sounds, idle air will open fully.
2.I will be idling then it will shut off, then i will try to start it but doesn't want to. Sometimes it will "back fire" through the intake.

I have changed the IAC, TPS, and fuel filter. I am lost with this problem oh and the check engine light is on

get codes and fuel pressure test. sounds like low fuel pressure but need to be tested to be sure. keep gas tank above 1/2 see if problem reduces......

[sharky92206]

this problem is not consistent. When i first start the car when its cold it will idle anywhere from normal to 2000 rapidly(also noticed when it down shifts). I started think it could be cheap gas or maybe even a vacuum leak. But i will get those codes and post them.

[sharky92206]

These are the engine codes:P0102, P0420, P0300

[j cAT]

Originally Posted by sharky92206

These are the engine codes:P0102, P0420, P0300

these codes are saying two different things first the maf is not happy! the pcm is saying too much air is bypassing the maf . vacuum leaks,pcv hoses etc....dirty maf or water getting to maf. p0420 says that your cat is n/g and because you have a impala this is no surprise.....p0300 says that misfiring is occuring that is potentially damaging the cat........you best look over the parts i mentioned and then if you cannot find anything wrong with your knowledge go to get checked out by an honest mechanic. no dealerships............

[sharky92206]

i was told by a friend of mine who is a mechanic that it is most likely a vacuum line leaking and to spray some starter fluid on the vacuum lines/fittings to find leak. I looked under the car and it appeared that this was the second cat cause it's not stock. I also have a cold air intake on this car but dont think water got to the MAF. I will check out everything you recommended much is appreciated. I will post what essentially was the problem

[sharky92206]

ok got me some starter fluid and began spray most the vacuum lines and.......no results; now I start to get frustrated. I thought to myself hey I'm just going to disconnect the MAF and see what happens I did and the car doesn't act up anymore. But should the car be running very poorly or high idle. Possible MAF going out??I'm not going to replace the MAF unless I'm absolutley positive this is my problem already dumped enough money to other sensors that didn't fix it and MAF's are usually 160.00

[j cAT]

Originally Posted by sharky92206

ok got me some starter fluid and began spray most the vacuum lines and.......no results; now I start to get frustrated. I thought to myself hey I'm just going to disconnect the MAF and see what happens I did and the car doesn't act up anymore. But should the car be running very poorly or high idle. Possible MAF going out??I'm not going to replace the MAF unless I'm absolutley positive this is my problem already dumped enough money to other sensors that didn't fix it and MAF's are usually 160.00

because of your modified air intake and the cost do what i suggest that , you buy a can of CRC maf cleaner and clean the maf. follow directions on can . be careful of the small wires, these sense air flow , even debris that can't be seen , will give incorrect pcm data, so for 6.00 give it a go....maf must be completely removed from ducting spray both sides no touching of internal maf metal wires etc.......dry before installing if this does not help you will need a new maf...........

[sharky92206]

isn't carb/throttle cleaner same thing??

[j cAT]

Originally Posted by sharky92206

isn't carb/throttle cleaner same thing??

only use crc maf cleaner! never use any carb/ throttle body cleaner on this maf part if you did or do you will need new maf , as these chemicals destroy the electronics imbedded in the maf!

[sharky92206]

I'm glad I asked. I didn't really think there was MAF cleaner. Are you referring to the chemical euther?

[j cAT]

Originally Posted by sharky92206

I'm glad I asked. I didn't really think there was MAF cleaner. Are you referring to the chemical euther?

no! CRC is a company that makes many products. the MAF cleaner is specially made for cleaning electronic equiptment. advance auto is one store that carries this item.

[sharky92206]

gotcha! ill pick some up as well as a set of those special torx drivers ill keep you posted.....thank you

[j cAT]

Originally Posted by sharky92206

gotcha! ill pick some up as well as a set of those special torx drivers ill keep you posted.....thank you

i did say to remove the MAF from ducting ........then clean. do not take maf apart! only the clamps securing the maf to the air ducts......

[sharky92206]

no this isn't that style it has to 2 torx tamper bits that hold it on looks kind of like a black plastic stick mounted through the induction