Very Slow Acceleration

[jon91]

When i rev the engine on idle it revs up slowly it doesnt jump rpms like if youre revving it. Also when you take off it doesnt even move at all even with the pedal on the floor. It picks up speed once its around 30mph. It can go over 80 if i want to but anything under 30 its just sooo bad. I replaced the tps and calibrated it based of the tsrm. The car shifts until it hits around 4k rpm with a head snapping shift. The 2-3 shift is also a head snapper kinda like if it has a shift kit lol. Im thinking of replacing the shift solenoids. I replaced the head couple years ago due to a hg problem. I remember when i had it with just the exhaust manifold after the rebuild it would rev up to 6k like in 2 secs. Not the case now. I havent had a code ever. Im starting to think it might be the catalytic converter that might be clogged, who knows. Any suggestions?

[jondee86]

Sounds like a timing issue so first thing to check would be the ignition timing. But you need to provide a bit more information on the car/engine, like the make and model and engine designation, turbo or N.A, that kind of stuff

Cheers... jondee86

[jon91]

Its a 90 Cressida 7mge auto. Thanks i might if solved the issue. I changed the two shift selonoids and changed the fluid and filter.

[Liquidhandwash]

could be the timing belt jumped a tooth. easy to check.

[jon91]

I checked the timing and it looks good everything aligns where they should. The crank in the 0 mark and the two pulleys on the cover groove. The only problem i found that it was out of time. I had to get a timing gun to fix it, no more pinging sounds but its still slow as crap when its cold. The rpms wont go up very high when revved.

[jon91]

This is about 3/4 pedal down

https://streamable.com/qoyd5

[jondee86]

Might be out of order here but AFAIK that engine should idle at 15-17 deg BTDC when warmed up, in neutral, A/C and other accessories all off. That is without shorting the diagnostic plug. With the plug shorted you set the base timing at 10deg BTDC.

Might be worth checking as retarded ignition timing can cause sluggish acceleration. It will also cause the exhaust to get hotter than usual.

Cheers... jondee86

[jon91]

I checked the timing with the car on neutral and it stayed around 11 with and without the diagnostic plug in. Idles nice and good. Now i just have to change those ujoints that came with the 1 piece driveshaft.

[73GTV]

Could you have a plugged catalytic converter which we see a bit here in the states.

[jon91]

I took the whole timing belt amd crank pulley out to start from scratch. Im just waiting for my crank seal to arrive to slap it in and put everything back together. I think my distributor timing might of been off too.