OHV works better without maf?? help!

[bates]

Alright the mechanic is havin real problems with this. So I figured the ole faithful board might be able to help me out.

As some have seen I swapped in a 98/99 motor, brand new, into my 91. Ran like a top, for 519 kilometres. then stalled once, then again down the road. Then it wouldn't run right the whole way home. kept wanting to stall and had no power. Seeing as how I needed it faster than I knew I could fix it, and I didn't have a code reader I bit the bullet and brought it to a mechanic. well he said theres lots of fuel pressure at the rail. and I have spark. That leaves air. He changed the MAF and said it ran better but still not right. He wound up trying a new computer, changing the o2 sensor and trying 4 more MAFs this week. Well I just picked it up and hes got a bandaid fix for now. It runs decent when it warms up now, the MAF isn't plugged in. This has gone beyond my comprehension now. Somebody please help! I'm hopin its something simple.

Any thoughts?

 

[bates]

O ya he said he wants to try an MAF off of a 99 (nopt sure how tis would be any better or even work but he says he can make it work even tho it has a dif type of connector and is obd2) Just thought I'd add that in.

 

[Creager]

hrm by the way you described how it was running with the MAF is exactly how mine was running without one!

id try the 99 one. is it a 99 computer? somewhere down the line the computer thinks its getting air when it really isnt. Maybe your computer is getting some interferance somewhere? i dunno not likley... interesting topic.

 

[Eneurb]

Sounds like your mechanic is more of a darts player. Is he using the correct MAF sensor?

 

[nascar_intimid]

what's wrong with darts?!?!? :fire:

 

[ExplorerDMB]

Sounds like your mechanic is more of a darts player. Is he using the correct MAF sensor?

Exactly what I thought! Hopefully you'll get the thing running right again. What kind of filter do you have on it? Is it an open-air type (Mac, K&N, etc.) -- cause if it is you can be getting debris on the filiment inside the MAFS that is causing it to fail out or not read correctly.

-Drew

 

[bates]

I have a k&n cone filter. Apprarently he tried a few different years of mafs. Stock 91 computer.

 

[Creager]

something isnt right

get a wiring diagram from the MAF to the PCM and check all those leads. See if one is grounding out somewhere it shouldnt or maybe a certin harness isnt in the right spot... something is configured wrong. i dont think its the MAF itself

 

[boominXplorer]

stock 91 computer is your problem probibly. What intake manifold are you using? Is it just a 99 shortblock? 98+ the iat's were inside the maf and before they were separate on the intake tube.

 

[huskyfan23]

Why not use a 98/99 computer?

 

[expo5.0]

the answer to that should be pretty apparent

its gonna be a lot easier to keep his current computer, if he can.

this does sound like a mass air sensor problem as opposed to a connection somewhere. isn't there anywhere you can go where they can retune it all? i know my place up here can do a lot of recalibrate that stuff.

 

[huskyfan23]

So an OBD I computer with an OBD II motor? Makes sense.

 

[bates]

I used the 91 plenum, with the 91 fueal rail, from there down is 99. I changed over all the sensors to the old ones. the bolt righht up and workes fine, only I don't have a low oil light, but who cares?

I got a chance to look at it tonight after driving it about 100 km's today to and from work. I stopped by crappy tire and picked up a paper filtert and put it on, cleaned the maf (which was dirty as hell ) then hooked it up and it ran PERFECTLY. So if it still runs fine when its cold in the morning I say its fixed and get a new mechanic.

I think the problem was putting too much oil on the K&N, as well as (stoopid me) putting some oil on the inside of the filter oops.

 

[Creager]

I think the problem was putting too much oil on the K&N, as well as (stoopid me) putting some oil on the inside of the filter oops.

that will do it.