I NEED maf sensor possibly?

[Q45phill]

bucking and sputtering between 1800 and 3000 rpm??? its a 1990 Q 45 with 150211 engine was rebuilt totally about 10000 miles ago ran great till i washed it finally and cleaned the engine last night now bucks and sputters hard like i have a flat spot in the tps or maf between 1800 and 3000...so lets hear ir gentlemen...thanks in advance...

[Q45phill]

okay wellhow about what do i need? i've cleaned the maf, but it idles great its only between the 1800 and the3000 or whenntrying to cruise at 22-25oo rpm that i have a problem????

[maxnix]

Have you inspected the connectors very closely? If the seal of the circuit board box breached?

[Q45phill]

no, no seal broken that i can see,and yes, i inspected the conectors and bent them down to make the connection a little tighter like the tutorial on here said...also my fuel pump is humming VERY LOUDLY , is it time for a new fuel pump? and thanks maxnix...

[Infinitiguy19]

Yes its beyond time if its very loud.

How does the car drive?

How is WOT AKA Wide Open Throttle?

[maxnix]

How is WOT AKA Wide Open Throttle?

No, don't do that! You may take out your FPCU, which is much more expensive.

Call Joe

http://www.infinitipartsusa.com

and order fuel pump, O ring and fuel filter or 2 (think about air filters and M1 oil filters at his great price) while 7% sale is still on.

Read Tanagalora's excellent posts in IOM.

[Infinitiguy19]

O I meant to do it once, I guess he can test the fuel pressure at idle.

[Q45phill]

WOT seems to be fine, but the pump is very loud and now the car has cut off twice while driving, also it still has the bucking and sputtering between 1800 and about 2500 RPM"S any tech know whats this might be? i'm going to replace the furl pump and MAF ASASP...

[Rex]

Replace the fuel pump (use OEM), o-ring and fuel filter SOON. I wouldn't try trouble shooting anything else until those are fixed.

You might ohm your injectors just to see if any are on their way out.

[yellow1342]

I got 2000 Q45 w/83k stalled twice past 7 days. about 15 month ago it shut off once and service light was on with MAF sensor error, but not this time. it starts and run. mechnic said there're two MAF sensors 300+ each?Does sound right? thanks

[maxnix]

Mechanic doesn't know Shinola from MAF sensors.

Get to a specialist. Even Autozone can read a OBD II scanner.

And please post a maintenance history when you have a mechanical problem.

[Q45phill]

i also have a SUPER STRONG fuel smell inside the car but not from the engine, only inside the car? could o ring be missing on fuel pump? its very strong in the car and trunk but not the engine bay area...???? anybody???

[Infinitiguy19]

Is it only when the AC is on? If so then read this: zerothread/203341

[goody90q45]

i also have a SUPER STRONG fuel smell inside the car but not from the engine, only inside the car? could o ring be missing on fuel pump? its very strong in the car and trunk but not the engine bay area...???? anybody???

You're not a smoker I hope.

The fuel pump is mounted on top of the gas tank which is behind the REAR seat. You can see it from the trunk by pulling back the rear trunk liner.

If the smell is heaviest inside the passenger compartment above the rear speakers and from the trunk close to the gas tank then the fuel pump o-ring is not seated properly or one or more of the mounting screws (6-8 IIRC) is stripped or missing. Did you just pay to have your fuel pump replaced?
Modified by goody94q45 at 9:43 PM 3/7/2009

[Infinitiguy19]

Mike is right there are 6 screws, You can see it in my Rear shock tower bar topic (Shameless plug). I think I know what happened the mechanic failed to use the original screws and used longer ones and puntured the tank.

See my picture and see if he used the same exact bolts that were on the tank.

I hope though that he just did'nt use the O-ring.

I am sorry about my previous post I only read the topic title and not the posts in the topic.

[yellow1342]

I got 2000 Q45 w/83k stalled twice past 7 days. about 15 month ago it shut off once and service light was on with MAF sensor error, but not this time. it starts and run. mechnic said there're two MAF sensors 300+ each?Does sound right? thanks

my mechanic fixed it!! he take the MAF unit out, clean with brake cleaner spray then use air to blow dry. put it back everything dunkey dorri! Just for your note. he just helped me changed air filter one week ago, the Q45's MAF is very sensitive, it's not broke but same as last time after changed air filter somehow touched the sensor and make them not functioning correct which worst could shut off the engine.

for your reference/thanksphil

[Infinitiguy19]

MAF sensors are very sensiive because they measure AIR and people ar'nt supposed to touch them.

Make sure not touch the actual sensor when using brake parts cleaner.

[maxnix]

You're not a smoker I hope.

The fuel pump is mounted on top of the gas tank which is behind the front seat.

Especially if his is located in the back seat!

[goody90q45]

Oops. Let me edit that. I meant way, way behind the front seat.

[Q45phill]

i thought the fuel pump was located directly behind the rear seat in the trunk under the carpet and a cover? also, why do i only smell the fumes /gas vapors in the car and not the engine bay area? is it true what they say about the fuel hoses in the engine bay leaking? i smellthis fuel smell ALL the time not just when the heat/a.c. is on...

[maxnix]

i smellthis fuel smell ALL the time not just when the heat/a.c. is on...

You have a 1990 Q45. How many times have you replaced each hose?

[goody90q45]

i thought the fuel pump was located directly behind the rear seat in the trunk under the carpet and a cover?

That's correct. It's directly behind the REAR seat under the rear deck (speaker cover). You'll need to pull both pieces of the rear seat and the rear deck to fix the leak and/or replace the fuel pump.

.....also, why do i only smell the fumes /gas vapors in the car and not the engine bay area? is it true what they say about the fuel hoses in the engine bay leaking?......

You're not smelling it in the engine bay because the leak is probably behind you on top of the gas tank. Reread my previous post (summary: fuel pump oring not seated properly) and start sniffing behind the rear seat and in the trunk to find the source of the odors.

[maxnix]

Remove the trunk bulkhead trim

DON'T SMOKE!

Source of fumes should be very apparent.

[Q45phill]

ok gentlemen UPDATE i have removed all rear seats and trim including trunk panel. what i've found is that previous owner was a HACK!!!! fuel pump has stripped out screws, different length screws and black rtv smeared all over the pump and tank!!! NOW THATS A HACK!!! what do i do next? i have the FUEL PUMP AND MAF on order but i'm almost afraid of whats next ... soooo ??? any ideas or suggestions? i'm sure thats where the fuel vapors and smells have been coming from.

[Infinitiguy19]

Take the pump out and see if the screws punctured the tank.

Trust me you need to replace your tank with a new and unmolested one, Why: Because this happened to me with my black 1991 Q45.

[Q45phill]

??? for paul wall WHAT HAPPENED? where did you get an unmolested.... what a word! unmolested..tank? salvage yard ok? the tank looks great, almost new from my pov....

[Infinitiguy19]

I should have said un-penetrated. .

I got one from a junk yard, but take the sending unit our and take a picture of the holes on the tank, or just look at the holes ans see if they go straight through. But I am 99% sure they will because word for word this is what happened to me when I was inexperienced with the Q and trusted every mechanic who was a mechanic.

Nico and the members of the Q45 forum taught me though.

Basically the story behind my bad experience which led to me needing a new tank was: The mechanic used longer screws because he lost the original ones and never said anything about it, and the ones he used were longer and thicker and then I had the gas smell in the car to the point where I got used to it. But we took it to a mechanic which I still trust to this day and he showed me what damage the previous mechanic did.

So we sued the shop and got the repair for free basically after I was done with him.

And RTV, screws or almost anything else won't hold up to pressure the tank is under.

[maxnix]

Might want to start looking around for another uncorroded fuel tank in a yard with a good collar that will only require steam cleaning and retapping the threaded receptacles in the collar.
Modified by maxnix at 8:45 AM 3/10/2009

[Q45phill]

got new fuel tank and boy is it so frsh and so clean , still waiting on pump and MAF have a quick ???, what causes the bucking and sputtering between 1800 and 2500 rpm"s IS IT THE MAF , or could a BAD FUEL PUMP be dying out and causing fuel starvation at higher rpm's?

[Infinitiguy19]

Why did you get a new tank if you did'nt confirm that the bolts penetrated the tank?

I would say either MAF or fuel pump.