HELP! Intermittent Stalling, tried everything.

[cbr900boy]

I was hoping my 2 cents would get you down the road for longer than this. I take it no problems before now?

If I were in your shoes I'd get the fuel pressure tested first. Don't throw parts at an unknown problem IMHO. It could be a bad or leaking fuel pressure regulator or the pump could have gone bad after a year. I have found that non OEM parts for the most part these days are hit or miss whether they work or not.

Also check all ground connections.

The relays I have seen fail like our ECU ones fail either due to a bad electric spike or moisture can get in them wrecking havoc on them. They are under $20 at most auto parts stores. I just don't think this is the problem.

Thanks again littlecaesar ill have to look into your suggestions. Evey part ive used has been oem so im not concerned about quality.

 

[cbr900boy]

Fuel Pressure regulator is the next place I would go

I am hoping its not cause they are expensive. I heard these rarely go bad. I might have to consider it though.

 

[cbr900boy]

You're basically throwing time and money at the truck hoping to find the problem without troubleshooting.

Your EFI relay can be switched with the tail relay to see if it is the EFI relay acting up. You can also switch the tail relay with the CO relay that's inside under the fuse block. Amazon has denso relays for less than $11 each shipped.

And FWIW, I recently had a relay go bad...so it does happen.

The way i see it is nothing is going to waste cause these things will evemtually have to be replaced sooner or later especially cause i have 269k miles on it. I think im going to try the relays since they are pretty cheap. Thanks.

 

[cbr900boy]

The way i see it is nothing is going to waste cause these things will evemtually have to be replaced sooner or later especially cause i have 269k miles on it. I think im going to try the relays since they are pretty cheap. Thanks.

Just ordered 2 new relays, I will update after I replace them.

 

[AntleredRuin]

I am hoping its not cause they are expensive. I heard these rarely go bad. I might have to consider it though.

My FPR was bad when I bought my '99 used about 8 months ago (of course, the test drive did not show this). Same symptoms as you, but got worse with time. Started stalling and hesitating every time I would let off the gas.
It was a toss up between the fuel pump, and the FPR, but then I noticed that the air intake silencer baffle had a bit of gas in it. The FPR was leaking into the intake through that little hose.
Replaced the FPR with a used one off eBay for $30 and good as new.

 

[cbr900boy]

Just installed the the EFI and circuit opening relays and so far so good. I will update later.

 

[diverscale]

First, check your obvious ground connexions.

Then, most likely, take your IAC out again. I think your IAC is the culprit here, as lot of members had the same problem, and it was the IAC (including me). Take it out, clean it real good, I mean, let it soak in cleaner. Then lube it before putting it back, and put bearing grease all around your seal before installing.

If it does it again, I could send you a IAC I have that I got on ebay, which I do not like in cold weather. You could try this one and see if the stalling stops.

 

[Squirt]

I had a similar situation. Also tested and/or replaced everything the OP has covered...ended up being both cats. They were completely destroyed... Looked like they had been sandblasted to near nothing inside. This was after my exhaust guy AND my pro-mechanic Dad had both sworn for the year I chased this issue that it was IMPOSSIBLE that the cats were bad. If all else fails, just don't forget about those annoying bastards under there that have soooo much to do with our toys taking a breath.......

 

[cbr900boy]

First, check your obvious ground connexions.

Then, most likely, take your IAC out again. I think your IAC is the culprit here, as lot of members had the same problem, and it was the IAC (including me). Take it out, clean it real good, I mean, let it soak in cleaner. Then lube it before putting it back, and put bearing grease all around your seal before installing.

If it does it again, I could send you a IAC I have that I got on ebay, which I do not like in cold weather. You could try this one and see if the stalling stops.

I appreciate your generous offer but I just replaced my IAC valve with a brand new toyota one.

 

[cbr900boy]

I had a similar situation. Also tested and/or replaced everything the OP has covered...ended up being both cats. They were completely destroyed... Looked like they had been sandblasted to near nothing inside. This was after my exhaust guy AND my pro-mechanic Dad had both sworn for the year I chased this issue that it was IMPOSSIBLE that the cats were bad. If all else fails, just don't forget about those annoying bastards under there that have soooo much to do with our toys taking a breath.......

My 98 only has 1 cat. I believe the newer cali models had 2 cats. I had my rig smoged not too long ago and passed with flying colors.

 

[Squirt]

Mine passed too, doesn't mean the cat isn't shredded. Definitely finish troubleshooting the topside first but don't count out the cat if all else fails.

 

[diverscale]

just pitching a quick and free idea here. You have checked for vacuum leaks after your throttle body, but have you inspected your piping for cracks/leaks between the MAF and the throttle body? I'd look at the connexion from the MAF to the airbox (add vaseline to the rubber) and for cracks where the mufflers attach to the main airpipe. That could cause uncalculated air to intermitently enter the system

 

[cbr900boy]

just pitching a quick and free idea here. You have checked for vacuum leaks after your throttle body, but have you inspected your piping for cracks/leaks between the MAF and the throttle body? I'd look at the connexion from the MAF to the airbox (add vaseline to the rubber) and for cracks where the mufflers attach to the main airpipe. That could cause uncalculated air to intermitently enter the
system

I ruled out any vacuum leaks. Im OCD so i replaced every single rubber hose inside my engine with high quality silicone hoses. Plus i replaced my intake piping with an airaid jr kit. My vacuum reads at 20 in/hg which is solid.

 

[Jayjayb96]

I ruled out any vacuum leaks. Im OCD so i replaced every single rubber hose inside my engine with high quality silicone hoses. Plus i replaced my intake piping with an airaid jr kit. My vacuum reads at 20 in/hg which is solid.

So were you able to fix the problem after swapping the relays or fuel pressure regulator?

 

[cbr900boy]

So were you able to fix the problem after swapping the relays or fuel pressure regulator?

I only replaced the EFI main relay under the hood and the Circuit Opening Relay under interior fuse block, this one directly controls the fuel pump from what I've read. My stalling problem in intermittent so I have to drive it around a bit to see if the problem is resolved. I will post my findings.

 

[cbr900boy]

Still no Resolution! Ok guys, here are the conditions that I have observed.

-It's stalls during very LOW speeds, like a crawl. Almost like when I barely just barely step on the gas and the stall occurs when I release the gas.

-It never stalls at a stop sign or stop light.

-It seems to occurs during warmer days, today was 80 degrees outside.

-It never happens under load, ie fwy.

-No CODES.

-Zero symptoms before it stalls, no sputter, no bogging down, just dies with all the dash lights still on. When I turn the key, it's starts like a champ and I continue driving.

-Occurs intermittently, not every day.

-Other then that, she runs perfect and strong when I floor it.

 

[LittleCaesar]

How are all the grounds?

Alternator OK? Battery and the battery terminals?

Last time timing was checked?

 

[cbr900boy]

How are all the grounds?

Alternator OK? Battery and the battery terminals?

Last time timing was checked?

Alternator is pumping 14.4 volts, battery is a new AGM only a week old, I replaced it when I did a Big 3 Upgrade along with new military terminals. (The stalling existed before this upgrade so it's not related.)

Besides the fender ground from the battery and the main ground located next to the oil filter, where else could I check my grounds?

How do I check my timing? I though the timing was adjusted if you had a distributor cap and rotor setup? Isn't our timing controlled by the ECU?

 

[cbr900boy]

I think that would be a waste personally. If a relay is gonna fail, it's gonna fail upon it being activated or deactivated. Doesn't make sense for a circuit opening relay or efi type relay to fail when the car has been running. Those are powered on when the key is turned on and they stay on. If I were you, knowing nothing else about the situation other than what you've posted, I'd try another maf. I know you say you've cleaned it and you have good fuel trims supposedly, but the situation you describe when it stalls makes me think maf.

Would a bad MAF go bad and not throw a code or have any other symptoms?

 

[LittleCaesar]

There is the one behind the ABS Diagnostic box on the upper manifold.

If it isn't fuel related and the IAC is new (so is the MAF) then I would say MAF but I know it is new.

I take it you don't have a scanner or app that shows live data still.