Dave????

[gcash81001]

http://forums.tccoa.com/showthread.php?t=93325

I need some help here thanks

[nickleman60]

greg, daves forum name is frdlvr30

[frdlvr30]

Ok greg im sorry i didnt get up with you or shane this weekend about your vehicles. I had some family obligations...you know how that is. It sounds like maf problem to me. You were on the right track with the fuel problem...but its related to pcm inputfor fuel delivery(maf) not the ouput (pump, filter injectors). If the maf is sending incorrect voltage signal to the pcm the fuel delivery will be incorrect, hence the reason for the popping and sputtering(lean). If you have access to a scanner that would be the easiest wasy to diagnos it. the maf voltage should be around .90volt at idle to 4.5-5.0 at wide open throttle. zif you have no access to a scanner i would suggest unplugging the maf with the engine running and see if it will rev up then. you could try to drive it, but it may be hard to keep it running. When you unplug the sensor with the vehicle running, as with any input sensor, it goes into FMEM or failure mode effects management. This is a permenantly set value for the pcm to go by so that the vehicle can limp home. Also known as limp mode. If youd like i could look at it tommorrow for you or you can try what i said. Likely that a bad maf WILL NOT set a code though, so dont go by that. I read on the tccoa that your egr had come unplugged? The 92-95 4.6l intakes are known for clogged egr ports...just so you know...more on that later. That will not cause the problem you are describing...Dave

[gcash81001]

I will check it out tomorrow, But i rode with the maf unplugged it did not make any differance

[frdlvr30]

Its hard, at least for me, to diagnos vehicle, sight unseen. Let me ask you this? When the engine is floored to wide open throttle while sitting still in park, what does it do? Does it go all the way to redline or does it sputter and pop through the intake like you had mentioned before?

[gcash81001]

it does it eithier way in gear or not, but goes to redline slower than normal

[frdlvr30]

Put a maf on it greg

[gcash81001]

ok I will keep you updated

[gcash81001]

fuel pressure read engine off, key on : 45 and running is 35

compression is 1-6 : 120 and 7,8: 150

[weaverms]

Dave,
Family always comes first so don't sweat it. I sent you a PM with my cell number, so give me a call whenever you got some free time. If needed, I'm sure I can get out of work early this week. Just let me know.
Shane

[gcash81001]

the maf voltage was .09 at idle and the voltage vent up to 18.00 volts at wot under no load, what do you think?

[frdlvr30]

That makes no sense greg. Its a five volt reference sensor. Meaning it operates from 0-5.0volts. 0 being not running, 5 volts being wide open. If you meant .90 volts at idle that is good, if you meant 1.80 volts wot thats your problem. Decimal placement is very important here, so get me the right values...Dave

[gcash81001]

do you read it thorugh the data feature of the scanner right?

[gcash81001]

when you go slowly to read line it read 6.02 but when you punch it it read 22.10 now
IT now read .067 now at idle too

[gcash81001]

I put a new maf on no changes

[frdlvr30]

alright, im gonna have to look at this thing greg. It truly sounded like a maf problem to me. However, if your voltage values are what you are telling me, then youve got a wiring problem. Id have to probe your wires and check for B+, sig return, v-ref, and ground. I cant possibly explain this to you over the computer. Call me tommorrow at 438-6525 and ill see if i cant come look at it for you tommorrow evening. If all those check out then possibly a pcm problem, but i dont wanna tell you anything else without personally listening to this thing and checking it out for myself...To answer your question, yes you use data logger for data retrieval. Things to look at would be maf, intake air temp (iat), engine coolant temp(ect), make sure the upstream hegos(o2sensors) are switching, Ignore the downstream sensors, they are for catalyst efficiency only, tp sensor voltage, cam sensor timing, ckp sensor signal, injector pulse width(milliseconds), evp or egr valve position-to make sure you dont have a stuck valve, and more imprtantly, fuel trim. Fuel trim is measured in short fuel trim and long fuel trim (sft and lft) and will show as percentages ex- +12%-would mean rich -12% would mean lean. Any thing over 18% means you have a air fuel ratio problem, be it to rich or too lean. You really need to look at long fuel trim closely, if there is an air fuel ratio problem it usually maxes out at 33% for one if not both banks(left and right). Make sure your checking all of this in closed loop(engine warm). Open loop (engine cold) is a whole nother ball game. I know this can be confusing if you dont know what the values mean, much less what there supposed to be. Figuring out which sensor is at fault, much less what the cause is can be impossible without some serious driveability experience. Thats why i say its time for me to have a look. Ive listed all this stuff just off the top of my head, and there is still much more that it could be...Dave

[gcash81001]

do you think you can meet me saturday a haygood around 3:00- 3:30?

[frdlvr30]

Im sorry greg, i have to go to richmond friday evening and i wont be back till sunday night...Ive got to do the family christmas thing with my fiancee's family...cant get out of it.

[gcash81001]

ok maybe next saturday then?