First background on the engine.
has been running in my coupe for a couple weeks now
stock i exhaust barring stromung muffler
stock i intake manifold and throttle
Miller PSIK and war chip with tune
Last week being about the first time id really got to drive it i put it through about 30-40 miles of test runs just cruising with a little spurt of speed every now and then. It was running magnificently, absolutely amazing (ask n2mye30). Put it away for the week as my commute doesnt warrant the power. took it out friday evening for about a 20 mile drive just wandering around for fun, was running quite well, a little stumble here and there on my way back home. Made note of it and contacted brody with the issues as he asked me to, thinking it might be a little thing in the low throttle range of the tune. Yesterday didnt get much driving in, just a quick run around with my dad to show him how it was going, no issues very short drive. Today i take it out head up to my uncles place to watch the LFC-AFC game with him, running fine on the way there (with the now known stumble at low revs and low throttle) runs fine at the half when we go get food. Leave his place after the game and head to my dads place, running fine still with the occasional stumble at low throttle, but still not significant enough to be worrisome. Im at dads for about 10 minutes then im heading out towards school, get on the highway to head out there and it starting to hesitate a bit. I see on my AFR gauge huge swings from way lean to way rich and i back off down to about 50mph. after about a mile it stabalizes and i get enough courage to get back up to cruising speed. So im at the Wolfpack Motorsports shop checking out the weekends progress on the Baja SAE car. Im there for about 10min and i take off back towards home, on my way back to the highway im getting some hesitation similar to what was on the highway so i back off and try to hold fairly constant rpm. I approach a stop light push in the clutch and it slow dies out, im watching the afr and it is fully lean. I manage to get it started and into a parking lot where it again dies out. After letting it sit for about 15-20 min i decided to give it another chance fired it up, now i can keep an eye on both AFR and manifold vac, at first it fires up just fine vac jumps to ~15in (where it is when idling normally) afr is a fairly calm. Then after about a sec of idling alright the vac starts to drop off gradually and AFR leans out and engine dies.
Things i tried in the lot:
re seat many connections
unhook o2 from computer (results in much worse idling for that 1 sec)
unhook ecu to reset
nothing had any effect, so i got a tow home
I did a quick google on vac gauge reading which suggests this reading to be a clogged exhaust. This would fit as i bought the cat from a junked car, who knows how bad it is. I want to know though a) if this fits with the AFR readings b) if there are any other likely scenarios.
For me best case is clogged exhaust as that can be easily fixed, what else is it likely to be (keep in mind that it was running strong recently with no indication of any major problems until todays events) almost everything is new within the past 80 or so miles (on the engine)\
thanks
has been running in my coupe for a couple weeks now
stock i exhaust barring stromung muffler
stock i intake manifold and throttle
Miller PSIK and war chip with tune
Last week being about the first time id really got to drive it i put it through about 30-40 miles of test runs just cruising with a little spurt of speed every now and then. It was running magnificently, absolutely amazing (ask n2mye30). Put it away for the week as my commute doesnt warrant the power. took it out friday evening for about a 20 mile drive just wandering around for fun, was running quite well, a little stumble here and there on my way back home. Made note of it and contacted brody with the issues as he asked me to, thinking it might be a little thing in the low throttle range of the tune. Yesterday didnt get much driving in, just a quick run around with my dad to show him how it was going, no issues very short drive. Today i take it out head up to my uncles place to watch the LFC-AFC game with him, running fine on the way there (with the now known stumble at low revs and low throttle) runs fine at the half when we go get food. Leave his place after the game and head to my dads place, running fine still with the occasional stumble at low throttle, but still not significant enough to be worrisome. Im at dads for about 10 minutes then im heading out towards school, get on the highway to head out there and it starting to hesitate a bit. I see on my AFR gauge huge swings from way lean to way rich and i back off down to about 50mph. after about a mile it stabalizes and i get enough courage to get back up to cruising speed. So im at the Wolfpack Motorsports shop checking out the weekends progress on the Baja SAE car. Im there for about 10min and i take off back towards home, on my way back to the highway im getting some hesitation similar to what was on the highway so i back off and try to hold fairly constant rpm. I approach a stop light push in the clutch and it slow dies out, im watching the afr and it is fully lean. I manage to get it started and into a parking lot where it again dies out. After letting it sit for about 15-20 min i decided to give it another chance fired it up, now i can keep an eye on both AFR and manifold vac, at first it fires up just fine vac jumps to ~15in (where it is when idling normally) afr is a fairly calm. Then after about a sec of idling alright the vac starts to drop off gradually and AFR leans out and engine dies.
Things i tried in the lot:
re seat many connections
unhook o2 from computer (results in much worse idling for that 1 sec)
unhook ecu to reset
nothing had any effect, so i got a tow home
I did a quick google on vac gauge reading which suggests this reading to be a clogged exhaust. This would fit as i bought the cat from a junked car, who knows how bad it is. I want to know though a) if this fits with the AFR readings b) if there are any other likely scenarios.
For me best case is clogged exhaust as that can be easily fixed, what else is it likely to be (keep in mind that it was running strong recently with no indication of any major problems until todays events) almost everything is new within the past 80 or so miles (on the engine)\
thanks
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