can the mass air flow sensor show his ass without the check engine light coming on?

[cecil bass]

I have a problem I just change the modular, coil and I'm still having problems under normal driving conditions. the car runs way better and smoother than I did before with the new parts, but is still sputtering sometimes under normal driving conditions, but not all the time only sometimes. when it's sputtering if I hit the gas the sputtering in goes away. could this be my a mass air flow sensor acting up? with no malfunction codes? how can I go about checking these things out? any help would be grateful ,Thanks.

 

[Hotrodbuick]

Do you have a wide band? My car was doing the same thing, while normal driving it was sputtering and little more throttle it would go away. It was my MAF sensor, it was showing good readings idling but when the boost was starting to come up is when mine did it. Hope this helps

 

[SHADOWII]

A mild tap w/a screwdriver or something light will reveal a problem if you tap it and the eng. stumbles, it's bad. Any chemicals, cleaning agents, or il can damage the sensor also, so if you cleaned your k&n filter and put too much oil on the filter, it may reach the sensor and damage it.

 

[earlbrown]

Oh yes it can. Years and years ago my MAF put me into FITS trying to diagnose a running problem. No code, not screwdriver test/stumbling, no nothing except a crappy running car.
It was before the translators came out so it took 12 tries to get factory type unit to run right (ish).

 

[we4Mateo]

If it's stock, it'll fail, so I'd look at the MAF first if ignition is done. To answer the OP question, yes, the MAF can be junk without a trouble code.

 

[Pronto]

When mine was failing I noticed random drop outs with the Powerlogger. If not for seeing those drop outs I probably would have been chasing my tail for a while. No bad symtoms just felt "off" on power. Translator and LT1 maf, no more dropouts.

 

[TurboBob]

the diagnostics in the ECM for the MAF are very limited. It is very easy for a flaky MAF to not set a code.

Bob

 

[cecil bass]

OK I was driving when I stopped at a stop sign the check engine light came on for like three secs then went off three codes popped up 13, 34, 44 . what does this mean?

 

[williamsGN]

http://www.gnttype.org/maint/malf.html

 

[whitehot1]

I'm going to make some suggestions and you can do with them as you want. It seems your car is in need of some maintenance and updated parts to make it run properly and be reliable. The bad news is it's going to require spending a little money but it will be worth it so you don't continue having problems. You don't have to do them all at once,just do them as your budget allows and what you think is the priority of the moment.

First if you haven't already do the spring cleaning as outlined on http://www.gnttype.org/maint/basics.html

Make sure your battery and alt. are good the auto parts stores can do a system check for you free.
o2 sensor get the Denso brand you can get it from rockauto.com at a better price than the auto parts stores.
Plug wires get the Bosch premium wires from Autozone they are good and only cost $26.00 lifetime warranty.
Cam sensor complete assy with cap - this is a part thats expensive but required. I was able to find a new one on ebay a year ago for $139.00 shipped. They normally go for around $300.00 +
Crank sensor get the BWD brand it is good O'Reilly's has it with a lifetime warranty.
Temp. control sensor BWD brand O'Reilly's lifetime warranty.
Maf Translater and LT1 3'' maf sensor www.fullthrottlespeed.com

 

[GNRick]

When my MAF was going bad the car was harder to start. Same symptom for stock maf and LT-1 MAF.

 

[cecil bass]

I check the whole system for vacuum leaks couldn't find anything what else could cause the car to drive flawless for a while then all the sudden it starts to sputter under boost and regular driving with a fast up down idle I really don't know what else to do.....

 

[TurboBob]

there are some ground wires bolted to the back of the engine (passenger side cylinder head), make sure they are tight.

with the car idling, wiggle all the wires under the hood.

how old is the fuel pump? Do you have a pressure gauge? (required equipment with these cars)

code 13 is a lazy O2 sensor, 34 is MAF signal loss, and the 44 is basically the computer trying to compensate and being unsuccessful...

Bob

 

[cecil bass]

there are some ground wires bolted to the back of the engine (passenger side cylinder head), make sure they are tight.

with the car idling, wiggle all the wires under the hood.

how old is the fuel pump? Do you have a pressure gauge? (required equipment with these cars)

code 13 is a lazy O2 sensor, 34 is MAF signal loss, and the 44 is basically the computer trying to compensate and being unsuccessful...

Bob

I don't have a ground strap on the pass side of the engine just the driver side. The fuel pump is new a walbro and yes I have a fuel pressure gauge the FP is set at 42 w/o vacuum connected. Sometimes the car runs perfect. Then all of a sudden the sputtering comes back....confusion!!!!

 

[GNRick]

I don't have a ground strap on the pass side of the engine just the driver side. The fuel pump is new a walbro and yes I have a fuel pressure gauge the FP is set at 42 w/o vacuum connected. Sometimes the car runs perfect. Then all of a sudden the sputtering comes back....confusion!!!!

Maybe somebody who is near you can swap a known good MAF for you to try. Where are you located? Another suggestion...maybe you have a bad spark plug wire?

 

[Pronto]

I don't have a ground strap on the pass side of the engine just the driver side.

Houston, we have a problem...

 

[earlbrown]

Houston, we have a problem...

Yep, you might have just found your problem. Crawl on top of the engine and look at the backside of the starboard head. There should be a cluster of black wires bolted to the head. Sometimes they get moved up to an intake manifold bolt or a transmission bell housing bolt.

 

[cecil bass]

It only one ground strap and its going to the transmission housing and there's one going to the heater core what should I do to fix this?

 

[cecil bass]

I'm in Denver colorado

 

[Pronto]

It only one ground strap and its going to the transmission housing and there's one going to the heater core what should I do to fix this?

It's can't (or shouldn't) be attached to the heater core. There are 7 ground wires divided into ring terminals. They should be attached to the passenger side head. Better get a flashlight and crawl over the engine to find all the black wires with white stripes on them. One wire is bigger at 12 gauge and one tan one. They all need to be grounded very well to the engine or the car will not be happy.