Wideband leads me to belive I have fuel pres reg issues.
Page 1 of 2

Author:  FloridaEdd [ Sun Sep 18, 2016 2:05 pm ]
Post subject:  Wideband leads me to belive I have fuel pres reg issues.

Took my buggy out today with my AEM wideband installed for the first time.
I've always had an issue where I run crappy after hitting the turbo hard for a couple of miles non stop.this would happen after I slowed down. Sometimes lasting the rest of the day.
I assumed it may be getting lean on top and causing self ignition. That's the best I could come up with.
Well turns out it was a rich condition.
After coming off boost it would still be at 10/1 and running like crap and clear up after a bit
Here's the break down.
Light throttle cruising around in at 13.5/1. to 14.5/1. Getting on it but no boost I'm running around 11.5/1 to 12.5/1
Hitting boost up to 5psi I'm getting as rich as 10/1 and sometimes around 12/1
After coming off of extended boost I was crushing at 10/1 rich not lean as I originally thought. Seems it hung up on the higher pressure for boost.

My first thought is fuel pressure regulator.
I do not have a fuel pressure gauge. I do have another reg ( used ) that I could try and or clean this one.
Looking for a nudge if I'm in the right direction.

Author:  JamalSpelling [ Mon Sep 19, 2016 12:09 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

VAF could be hanging up or going out, I don't think they were designed for off roading.
Maybe dust condition is causing it to stick?
Check connector as well, I've had problems with loose fit and ended up hardwiring/bypassing
connector and securing with silicone.
Should be vacuum connector on regulator as well, make sure vacuum is functional,
could be injector issue too. Stock injectors?

Author:  FloridaEdd [ Mon Sep 19, 2016 4:09 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

Stock injectors. They have been replaced last year but they are stoc specs. When I had leaky/ sticking injectors before my fuel pump would cycle over and over when the key was first turned on which I'm not experiencing.
This issue has lasted me all day before and if the injectors were stuck/leaking I would be hearing that cycling. I always listen for it.
My afr jumps around slightly when going over rough terrain which I expected due to the "barn door" flapping around but only slightly. I have the harness secured to where it won't flap around or wiggle the plug. I could hard wire it though. I was in the top of it a couple of weeks ago to set the spring back to its original position and it all moved Freely. I had tightened the spring one notch some time ago and put it back after I was thinking it was lean on the top in boost.
I had an issue before where crap had built up inside around my fuel pressure regulator and watching my boost and afr it sure seems like the culprit.
I'm gonna pull it and clean it can't hurt anything.
Thinking I will just get a cheap mechanical fuel pressure gauge but I have so much going on with gauges one more is the last thing I want.

Author:  JamalSpelling [ Mon Sep 19, 2016 10:23 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

The barn door is finicky as hell.
One notch won't do much.
I think I had mine up to a full turn, so much it wouldn't idle,
I had to drill out the plug on the air bypass just to get enough
to idle. Then after sitting for extended periods of time, it became
too stiff to allow airflow to open the darn thing, so I wouldn't
get any fuel. I've got an MR2 MAF on the back burner to see if
I can eliminate the fuel cut and not have the set the flapper
so stiff.
Anyway, I think you should tighten it a little more than a few notches and give it
a few runs to settle in and go from there.

Author:  FloridaEdd [ Tue Sep 20, 2016 2:35 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

I only did it one notch at the time because I didn't have a wide band to monitor it. One notch did take away some stumbling I was getting over rough terrain and seemed to smooth it out a little.
If it seems like I'm taking baby steps here it's because I am. I don't want to assume anything and screw it all up.

Author:  FloridaEdd [ Sun Oct 23, 2016 1:53 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

I'm back. Ok I got a new clutch and m back up and running. So I disregarded my thinking of fuel being the issue and came back to most fuel issues are electrical related. I always default to the advice I get here as its way better than my hypotheses.
So I changed the coil ,no difference,I changed the knock box, no difference, tested the map per my Turbo supplement I finally have and it was with in specs ,,,,,untill I checked the moving resistance and then I was all over the place. 150-175-200-125-400-225-300 ect ,,these are examples but you get the idea.
Now to round one up.
Thank you for pointing me in the correct direction.

Author:  FloridaEdd [ Sun Oct 23, 2016 3:24 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

Any other info on the mr2 maf you could give me,year,what may be involved ect? I'm not scared to be a guinipig ,,,I appreciate it

Author:  redneck racing [ Thu Oct 27, 2016 7:55 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

what i found tuning my turbo motor is you can keep adjusting the afm a notch or 2 at a time than give it some driving to adjust its self. i used bigger injectors and had to really tighten mine but once you get it dialed in they work great, but mine took about a week of daily driving which is kind of hard in a buggy.

Author:  FloridaEdd [ Fri Oct 28, 2016 4:03 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

After inspecting mine I noticed the strip on the pcb board that the arm sweeps across is damaged.
I'm looking into Toyota truck maf which looks close after checking specs on line but joined a Toyota truck forum to try to narrow it down.
I do appreciate the input,I'll take any I can get

Author:  FloridaEdd [ Tue Nov 15, 2016 9:05 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

So I repaired my maf and it did not fix my issues ( it did fix a few flat spots though )
With my maf spring in its original position where it ran fine for the last year in idleing at an AFR of 12/5 to 11/5. It's so rich it about burns you're eyes. You can hear little blop,blop,blop out the exhaust.

So here is what I've done so far,,I wanted to try everything I could think of before asking for help but I'm almost out of ideas.

Checked the plugs. They were all med brown with a hint of black on the back sides. They all looked the same. I replaced with stock plugs set at .40.
Checked the ohms of the wires and they tested good.
Pulled the distributer. Disassembled it ,( while in there I noticed I was not getting full advance so I put in a spring with 2 more coils ) cleaned and tested the pick up ohms.
Installed brand new MSD Blaster 2 coil. My coil tested good but I wanted to be sure,so now I got an extra one.
TPS tested good and I replaced it with a known good one just to be sure.
Knock box was replaced with a known good one.
My maf tested good but my contact strip was worn. I moved the pickup forward just a tad to ride on a virgin part of the strip. This fixed some flat spots I was getting.
Fuel pressure reg was replaced with a known good one.
I added two ground straps and soldered some ground wire connections that had previously been crimped.
My TPS harness had some corrosion where the wires had been pricked so I cut out the bad spots and soldered and shrink tubed them.
Replaced my alternator as the bearing was on its way out. I ran it for a minute and the alt pulley got too hot to touch.
Checked my coolent temp sensor.
Pulled the injectors and back flushed them and got no junk out of them. I know this doesn't tell me much but more on injectors in a few.

So none of this fixed my issue.
Just a quick refresher.
It used to run great untill I got on it and ran boost for a mile or so,on boost I was running about 10/1 AFR and that seemed good. When I would slow down it would stay at a AFR of 10/1 too rich if not in boost,off boost I would run 12/1 approximately, Some times it would clear up in a few minutes or hours. But now it just is there all the time.

I'm able to unplug the maf while running and it will almost die and then just keep running. It runs shitty and dies if I accelerate but it runs. This don't seem right.

Running it if I rev to 5000 rpms my AFR is around 8/1. So I started adjusting my maf spring and I'm able to get it to idle at 13/5 to 14/5 AFR. However this is not my solution. It is simply compensating for what ever the issue is. So while running it with the tighter spring it fixes it's self for a second and my AFR drops to 16/1. If my spring was in its original position the AFR would have been right on. I should add this testing is on the trailer with the rear end jacked up. All the while from idle up ln getting blop,blop,blop and real strong exhaust.

So I'm thinking injectors. These were bought about a year and a half ago or so and seem a little noisey.
So I'd like to know if there is anything else I should check before just buying injectors.

I plan on hard wiring my Maf tomorrow as I can remove the plug with the clip in place. I'm also gonna test my o2 sensor. But after that I'm out of ideas.
I know this is a lot to read and I hope I explained it good enough to be understood.
Thanx Edd

Just thought of this. Could my timing belt have slipped a tooth?
Nope because it would not clear up.

Author:  FloridaEdd [ Wed Nov 16, 2016 11:38 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

New injectors are on there way to me but I'm still open to other suggestions as the injectors are just part of the elimination process and by no means am I sure there my issue.

Author:  jaguar,vettes&sprints [ Wed Nov 16, 2016 7:23 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

Those MAF are good science...I hate those little buggers
So.E would say if you mount them vertical or harizonal
Makes a big diff
What is your compression reading now
Sound like your running it to hard to long
I would shit can the 3cyl turbo and get a gxr or something
That will take the abuse
These little engine were great for what they did
You my friend are trying g to do to it what should not or can not do
They certain ly were not design for rough service

Author:  jaguar,vettes&sprints [ Wed Nov 16, 2016 7:42 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

Sorry on my "not so smart" phone
The electronics just don't work well being tosselled around
G10 being bounced up down a dirt path just sound like a Money
Pit.... look at the MAF inside wiper,door, the whole works looks very fragile
Back in the day the kids that were ralley racing these cars
Would shitcan. the stock electronics
For standalone. Units
Like Mega Squirts while upgrading the internals....
The point I'm getting to is ....
These little engines were great what they were design to do
Make to drive.!
But not good at dirty rough service they
just won't hold up

Author:  FloridaEdd [ Wed Nov 16, 2016 8:26 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

I can meet you half way.
I agree the maf is not the best design for my application how ever my worn contact strip was my fault. When I rolled my buggy oil got everywhere in the intake system and worked its way into the maf from inside. I cleaned it out half ass and it attracted sand. Not much just a grain here and a grain there when I would open it and that ate up the strip. Had I of not been able to fix it a standalone was my next choice. I studied nstallation manual for the mega squirt systems and it seemed doable for me.

I don't agree the rest won't hold up. After going through the engine and servicing everything , I've put over 3000 off and on road miles on it this year alone and have had no issues. That's not running to the grocery store miles or racing someone from stop light to stop light , I drive balls out 90% of the time,higher end of the rpms and in the boost. Believe me when I say you would ring my neck if I drove you're car like I drive my buggy. Also aside from the maf everything else can be found on just about every off road vehicle out there. All off road vehicles are harder on parts and you are always having to maintain them and replace items due to abuse. My parts cost 1/4 of what replacement parts cost for any side by side Razor ect and I can have most parts within a day's time. I can rebuild my engine for less then 500$. It has a great weight to hp ratio as well.
Just my opinion

Author:  FloridaEdd [ Wed Nov 16, 2016 8:43 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

Missed your first post. Haybusa engines are the ones preferred for these buggies but two draw backs for me. My knees are bad and a clutch would kill them and the 4000$ price tag.
I didn't do compression as it feels good and unless compression issues can come and go that's not it.
In a car 200,000 miles is doable. Off road I'm happy with 10,000.
This buggy and alot of others came with stock metro engines and they have been going for 18 years. Have no balls but they do good as far as durability. I still agree the maf sucks.

Author:  JamalSpelling [ Wed Nov 16, 2016 11:43 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

'87 toyota MR2 MAF

Knock Box Sensor/ignitor is go/no go,
it's either good or fryed, no in-between,
it either works or fails.

compression check?

sounds like you're more than pig rich, MAF!

close the gap on the plugs, but that's not your problem

injectors....flow test, clean, and service (screenS & seals) that's about it,
runs about $100 or less, they will give you a before and after reading.

you could have an unmetered air leak, I would look for that, but
suspect MAF!

open the throttle plate and shine a flashlight in, how bad is the gunk?

Author:  FloridaEdd [ Thu Nov 17, 2016 7:06 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

I just had my intake hose off to pull the injectors and inside the throttle body looks good. No oil gunk ect.
I gapped the plugs at 40. The ones I removed were gapped at 42. I didn't want to change them too much while I'm chasing my tail.
My vacuume is 15 to 17 lbs which is what it has been since my cam and rebuild last year.
The injectors I got were new not reman , dealer close out for 102.00$ to my door. These are the same ones I have in there now which are about 2 years old.
The maf I tried was a Cardone reman maf 74-9106 showing to be for a Toyota MR2 1987. I got it sitting here and could try again.
I haven't seen anything that would point me to compression issues,,also it's not acting like it did when I had a burnt valve.
I'm not in denial that it could be my maf,I just don't have another to try. I'm trying to eliminate every other possibility before dumping cash on a stand alone just to find out my issues were some other item I did not check.
I mentioned above about driving it hard ,,I should of also said it has never been run hot,I have a large 4 core aluminum radiator and my fan only comes on ( for a minute or two) after slow technical trail riding. My boost has never been over 7psi and I change the oil often.
Computer issue ? Is that possible ?

Author:  FloridaEdd [ Thu Nov 17, 2016 7:13 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

When I unplug my maf should it continue to run? Runs like crap but still idles. This has me thinking something other than maf. There's only so many things it could be and I'm far from being frustrated yet.

Author:  CJDavE [ Thu Nov 17, 2016 8:42 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

It should continue to run, but run like crap. The ECU just feeds a guesstimate of fuel based on throttle position in an attempt to limp you home if your MAF craps out in the middle of a road trip. Granted when I had a faulty MAF, the car would run super rich (black smoke out the tail pipe) and then die with wet plugs (flooded).

Author:  FloridaEdd [ Thu Nov 17, 2016 10:46 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

Thank you. That clears that up for me. One less thing I have to wonder about in my quest.
Thanks Edd

Author:  FloridaEdd [ Thu Nov 17, 2016 1:34 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

O2 sensor tested good. I hard wired the maf tracing the wires back untill I found the original splice. The wires were soldered and had shrink tubing on them. I cut them there and spliced in new longer wires.
So it seems like it is down to my maf or injectors. I'll know next week when my injectors get here.

Author:  JamalSpelling [ Thu Nov 17, 2016 11:25 pm ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

So I'm thinking your maf is really messed up dude.

And you should rethink the MR2 maf, you just gotta loosen up the spring
so you can get enough airflow for idle, unless you got an idle air bypass screw
you could open that up as well for idle.

So the car's designed pretty much at idle it's gonna keep A/F at 14.7:1
the O2 sensor feed the ECM and ECM varies injector duty constantly to
keep it at 14.7:1 that's why on a wideband your gonna see the reading
hover just over, then under, then over then under, in fact you can hear
it as well the way the motor runs. It's too rich so it slows down the injectors,
then its too lean so it speeds up the injectors, back and forth to maintain
as close as possible to 14.7:1 and it does it very quickly. So if your A/F is
off especially at idle, and everything else checks out, then you have maf issues,
too bad you don't have an OE spare to swap out for testing.

I never had rich issues at idle, regardless of injector size, but did have lean
issues when my spring was too tight, not letting enough air in for the motor to run.
Actually the issue was fueling as the barn door wasn't moving, so no fueling. But you
can open up the factory sealed idle air bypass to compensate, to get an idle and the ECM
will adjust the fueling based on the O2 sensor input and disregard the maf reading
because the flappers not moving if you have it too tight. Once you get cruising and
under load you'll have enough airflow to move the flapper and the ECM takes over
but only to a point, you can only adjust it so stiff, if you go too tight you're screwed.

Our OE injectors are 210cc, the only time I got those kinds of readings under load
was when I was trying 380cc injectors, so you have definite rich condition.

So let me tell you what I think you're issue may be aside from the MAF, and you
tell me if it's plausible on your buggy. I think it's your cold start injector, I also got
similar rich conditions when I tried using the cold start injector to add fuel
during high boost, but it was too much and I couldn't control it, so I started
upsizing the injectors until I found the right size for my application.
The cold start injector is an independent system, it is always hot and it is the
timer switch which completes the ground to turn it on for cold starts. I suspect
it may be grounding out and adding a shitload of fuel when you don't want it.
Easy way to tell would be to unplug the connector to disable the injector
and see if the problem goes away.

Author:  FloridaEdd [ Fri Nov 18, 2016 2:31 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

Ok. So if I can get it close the o2 sensor should correct it as needed. That explainers my slight fluctuation of AFR at idle. I know it took awhile to type that all out but it has helped me to understand things a little more. Thank you.
My AFR is off at idle but gets further off the more throttle it gets untill it starts to break up.

I looked on line more this evening and it appears there is a large MR2 maf and a smaller MR2 maf. I have the larger one ( of course I do ) I had to use an adaptor hose to hook it up to my intake hose and I had to modify my air filter adaptor as the intake side had a larger square opening. The internals are the same with one number difference on the PCB board. I'm thinking I'm trying the wrong Maf.
My cold start injector is not hooked up. It has fuel but no signal wires and the cold start injector timer is not hooked up either ,,
I found a used sprint maf n Canada for 250$ shipped. I'll go sit n my buggy and make engine noises before spending 250$ on one. I say that now but I've spent more on less,,that just seems excessive. I'd rather try to make the MR2 work for me if I can..
Thanksgiving is around the corner so the wife has me cleaning up all my shit from this last year. We have thanksgiving at our house and it's like a reset point for me so my time just got limited for the next week.
I'm intrested on what you're thoughts are on the larger and smaller Maf. I'll try to get a pic of it today.
Thank you

Author:  JamalSpelling [ Fri Nov 18, 2016 10:33 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

Yeah, that's what I thought you'd say, that it wasn't hooked up.

This may help you understand correct A/F ratio.

Author:  FloridaEdd [ Fri Nov 18, 2016 10:56 am ]
Post subject:  Re: Wideband leads me to belive I have fuel pres reg issues.

Very interesting. Changes my idea of what is actually rich and lean. I don't know why but I thought 12 was close to ideal. I went ahead and book marked it. Thanks

Page 1 of 2 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group