My 85 305 tpi TA jerks alot. Right after I shut down the motor I diconnected the fuel line to the fuel rail and it seemed like there was no pressure. I dont have a guage so I put the end of the line in a container and it pumped more than a half pint in 15 sec. Also I pushed in the fuel rail fitting and it just dribbled out. Shouldn't there be more presure at those places. The car takes a few seconds to start and jerks at about 1500rpm's replaced everything I thought it was tps,iac,plugs,wires,cap,rotor,ingnition module. NEED HELP PLEASE!! If your not in it your behind it.

 

My cars does a little jerk action to around 1500RPM, I changed the fuel pump, strainer, fuel filter and it wasn't any of that stuff. Mine still does it. Put your car in neutral and raise the RPM to 1500, does it bog?, yes?, then you're in the same boat I'm in...namely, the Titanic.

Steve

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89 GTA G92
305 TPI WC 5spd w/3.45
Accel Cap & 8mm Taylor's
Custom 4" Cold Air Induction
Jet Airfoil
K&N Airfilter
160 deg stat/fan switch TB Bypass - Steel Rad
Cat back 3" Exhaust w/Terminator Muff.
HiGh FlOw Dynomax Cat
Spohn LCA's - KYB GR-2's
Moroso Crank Bolt and roller pilot bearing.
New Fuel Pump!
Autometer Vac+Oil Temp
2000 Yamaha R1 150hp 385ibs

 

Its hard to tell from here what sorta pressure you have. It sounds low, but thats a guess on my part.

You really need to buy/borrow/steal a pressure gauge and check it out if you are worried about the pressure. The concern is almost always how much pressure you retain after shutting off the engine. Sometimes you run into a problem of low pressure while its running, but then the car generally runs lousy all the time.

I dont think thats what your problem is, unless you have a leaky injector. Usually a jerk/miss at a specific rpm/range is ignition related. This is where a cylinder balance test comes in handy, at least you can track the cylinder down that is the problem, but most of us dont have the equipment necessary to do that. I'd suggest making sure the ignition is all hooked up right, and maybe check your compression. Checking the fuel pressure cant hurt, and its really simple if you have a gauge.

 

Well I solved the hard start I installed a new fuel pump and now it start's good. But I still have a jerk at 1500rpm's guess I'll just drive it.