3.0 random stutter, wont accelerate.
08-06-2014, 09:55 AM
#81
Aloha from Hawaii, I've been dealing with a similar issue on my 3vze 94 pickup M/T, 4x4. I noticed a drop in power at higher speeds 35+mph where my RPMS would continue to increase, but my speed wouldn't. My fan pulley bracket then froze up, causing one of my belts to bust, so of course new fan pulley bracket and belt. I then changed my timing belt, water pump (was leaking), thermostat, PCV, VAFM (out of spec) and upper air duct/hose which had a huge crack in it, O2 sensor (out of spec), TPS (out of spec) and correctly adjusted it, replaced all 6 injectors with reman'ed Densos, new plenum gasket, throttle body gasket, cleaned out throttle body and plenum, new valve cover gaskets, replaced fuel pressure regulator cus fuel pressure was too high at 48-50 PSI and supposed to be 38-44PSI, replaced fuel filter. Truck runs better, but still loss of power, especially under load and going up hills, so bad I can't safely drive it, I had to coast back down a small hill that I couldn't make it up and truck almost died, so that I could get a running start going up it. Fuel pressure at delivery rail is now good at 38-40 PSI when key is turned to On and when truck is idling...However when the truck turned off, the fuel pressure drops to 0 in seconds, when the FSM says it should remain above 21 PSI for at least 5 minutes after turning off engine...I then switched my Headlight relay and EFI relay just for fun and tried starting, it started and idled fine, but check engine light came on with code 25: Air-Fuel ratio, lean malfunction (check engine light was not on before switching relays). Should my fuel pump be my next target? Are there any other tests before going in to change fuel pump? Does the drop in pressure mean I have a weak fuel pump or a leak in fuel system? I can't find any leaks. Any help is greatly appreciated..my trucks been out of duty for 2 months now. Mahalo!
08-21-2014, 09:41 AM
#82
Issue Discovered: I took my truck to a mechanic and it turns out that my timing belt was off by 1 tooth on the camshafts...I was so sure I had done it right and had everything lined up...He also told me after doing a compression leak down test that my cylinder #2 is misfiring...screw me...I had tested compression myself and all 6 cylinders tested good with an average of 145psi, but I was not able to perform the leak down test which the mechanic said shows that #2 cylinder is not holding pressure. What can I do at this point? Is it ok to drive my truck?
08-22-2014, 12:07 PM
#83
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Location: Logan, Utah
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Stutter fix
I had the exact same thing happen with my 4runner. I would rive it around and it would run great but just randomly stutter then back to running fine. It wouldn't matter what gear or rpm.
The fix was to take the black cover off the airflow netter and clean the contact strip on that sensor. Fixed mine completely.
The fix was to take the black cover off the airflow netter and clean the contact strip on that sensor. Fixed mine completely.
Hey all,
Well I've been trying to fix this one for a while but its getting the best of me and i'm getting really frustrated.
Vehicle:
93 4runner
3vze 5 speed
307,xxx miles
running with 87 octane fuel.
Situation:
every 20-60 miles my truck will have a hick up. The motor will seem to cut out for a split second and bounce a lil. The problems been progressively getting worse for the last 2 months. The rate it happens seems to be the same but now the hick ups last longer. My mileage has dropped to 12 mpg when before it was consistently running at 14-16 on 35's. This week my truck stuttered at around 10mph and wouldnt take off on the freeway in stop in go traffic (always fun in the fast lane). I keep throwing parts at it trying to fix the problem from what I can dig up online but i'm having no success and I fear its going to get me stranded. I took the day off from work (after failing to make it to the freeway and having to pull off the side of the road til my motor would clear out and rev up), to address this problem. All advice is heavily appreciated.
On a side note, 2 weeks ago the odometer and tripometer stopped working, but the speedo is fine. Shouldn't be related but I thought I'd mention it.
Parts replaced and checked:
New ngk iridium plugs
Import direct plug wires
Import direct rotor and cap
New air filter
New 02 sensor
New fuel filter
Timing checked +12 degrees
idle 900 steady
vacuum lines leak free
Parts replaced last year if applicable to the situation:
Alternator
Battery
Timing Belt
Power steering Belt
Alternator Belt
If you need more info please ask
.
Well I've been trying to fix this one for a while but its getting the best of me and i'm getting really frustrated.
Vehicle:
93 4runner
3vze 5 speed
307,xxx miles
running with 87 octane fuel.
Situation:
every 20-60 miles my truck will have a hick up. The motor will seem to cut out for a split second and bounce a lil. The problems been progressively getting worse for the last 2 months. The rate it happens seems to be the same but now the hick ups last longer. My mileage has dropped to 12 mpg when before it was consistently running at 14-16 on 35's. This week my truck stuttered at around 10mph and wouldnt take off on the freeway in stop in go traffic (always fun in the fast lane). I keep throwing parts at it trying to fix the problem from what I can dig up online but i'm having no success and I fear its going to get me stranded. I took the day off from work (after failing to make it to the freeway and having to pull off the side of the road til my motor would clear out and rev up), to address this problem. All advice is heavily appreciated.
On a side note, 2 weeks ago the odometer and tripometer stopped working, but the speedo is fine. Shouldn't be related but I thought I'd mention it.
Parts replaced and checked:
New ngk iridium plugs
Import direct plug wires
Import direct rotor and cap
New air filter
New 02 sensor
New fuel filter
Timing checked +12 degrees
idle 900 steady
vacuum lines leak free
Parts replaced last year if applicable to the situation:
Alternator
Battery
Timing Belt
Power steering Belt
Alternator Belt
If you need more info please ask
.
09-28-2020, 08:46 PM
#84
Registered User
Thread Starter
Long overdue....
I know this thread is many years old now, but for anyone that it may help down the road, I was able to get this resolved. The problem turned out to be the fuel pump. While doing all my checks, i hadn't checked the fuel pressure. I assumed since the truck ran, the fuel pump was working correctly. I ended up ordering a gauge from LCE that bolts onto the fuel rail permanently. The numbers were way out of specification from where they were suppose to be. Replacement of the pump brought the truck back to its correct running condition. Hope this helps someone
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