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Morning All,
My 1998 GEMS V8 is having trouble and I'm at my wits end. After suffering low compression, I bit the bullet and had the engine completely overhauled and rebuilt by V8 Developments. It's had new everything, pistons, top hat liners, bearings, the lot. Whilst the engine was out I have replaced brake lines, suspension components, engine mounts, gearbox seals, all sorts.
The engine has been re-installed and it fired up pretty much on the first attempt and ticks over just fine. Sounds smoother than it ever did, and it doesn't leak any fluids..... yet.
The problem is it doesn't have any get up and go. It will accellerate but as soon as you hit a hill it slows and struggles to climb it. It doesn't seem to kick down when it used to, and there's just no torque. It will rev (better but not smoothly) if you force it in to a lower gear and get up a hill, but otherwise it sort of bogs down like it can't breathe.
I thought maybe fuelling or air metering or something like that. It's very similar symptoms to a bad MAF.
I've had it on the Nanocom, and there are no fault codes, the MAF is returning expected values, in fact all the sensors (on all the systems) look to be in line with what I'd expect. I've gone through these forums and tried all the common remedies for a sluggish V8.
I've tried a different MAF and it made no difference... but the engine stalls if unplugged whilst ticking over, so I think it's good.
It's had loads of new petrol and new fuel filter.
No obvious air leaks anywhere I can see or hear.
Tickover is smooth, and it revs freely when standing still in park.
HT leads are only a couple of years old.
Sparking plugs are only a couple of years old.
Almost everything is either brand new, or a couple of years old.
Where do I go from here? My brother thinks the CATs might be blocked. CATs are aftermaret ones from CAT2U. They have been sat a while waiting for the engine to come back, but they seemed fine before the rebuild.
I'm going to loosen the jont between the headers and the cats and try driving a bit to see if it accellerates any better, also I plan to test the spark plugs are all tight and gapped, but is there anything else I should be trying out and testing???
Like I say it starts and runs fine, but has no get up and go, feels sluggish and starved of fuel or air or both, but I've checked everything I can think of.
My 1998 GEMS V8 is having trouble and I'm at my wits end. After suffering low compression, I bit the bullet and had the engine completely overhauled and rebuilt by V8 Developments. It's had new everything, pistons, top hat liners, bearings, the lot. Whilst the engine was out I have replaced brake lines, suspension components, engine mounts, gearbox seals, all sorts.
The engine has been re-installed and it fired up pretty much on the first attempt and ticks over just fine. Sounds smoother than it ever did, and it doesn't leak any fluids..... yet.
The problem is it doesn't have any get up and go. It will accellerate but as soon as you hit a hill it slows and struggles to climb it. It doesn't seem to kick down when it used to, and there's just no torque. It will rev (better but not smoothly) if you force it in to a lower gear and get up a hill, but otherwise it sort of bogs down like it can't breathe.
I thought maybe fuelling or air metering or something like that. It's very similar symptoms to a bad MAF.
I've had it on the Nanocom, and there are no fault codes, the MAF is returning expected values, in fact all the sensors (on all the systems) look to be in line with what I'd expect. I've gone through these forums and tried all the common remedies for a sluggish V8.
I've tried a different MAF and it made no difference... but the engine stalls if unplugged whilst ticking over, so I think it's good.
It's had loads of new petrol and new fuel filter.
No obvious air leaks anywhere I can see or hear.
Tickover is smooth, and it revs freely when standing still in park.
HT leads are only a couple of years old.
Sparking plugs are only a couple of years old.
Almost everything is either brand new, or a couple of years old.
Where do I go from here? My brother thinks the CATs might be blocked. CATs are aftermaret ones from CAT2U. They have been sat a while waiting for the engine to come back, but they seemed fine before the rebuild.
I'm going to loosen the jont between the headers and the cats and try driving a bit to see if it accellerates any better, also I plan to test the spark plugs are all tight and gapped, but is there anything else I should be trying out and testing???
Like I say it starts and runs fine, but has no get up and go, feels sluggish and starved of fuel or air or both, but I've checked everything I can think of.
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