Some Bucking at Low-end...then pulls like a mule, Trying to get all the bugs out--I need your help Options

[computers4kids]

I need your help...I've got my transplanted djet 2ltr (76 de-smogged motor) in and running...and driving. I'm trying to get the motor running good but I'm having a problem with low rpms.

If I try to slowly accelerate the motor seems to "buck," hestitate until the motor reaches about 3,000 rpm then it's smooth sailing. However, if I put my foot into the pedal harder and run through the gears it pulls hard and strong like a mule....awesome.
Below are some things I've done:

• valves adjusted while engine was cold .006 and .008(exhaust)
• Installed new petronix ignition
• Set timing at 27 degrees at 3500 rpm
• Completly removed and cleaned throttle body and blew out all the ports with carb cleaner
• Cleaned throttle position contacts (excellent condition) and adjusted idle and full throttle contacts using an ohm meter
• all injectors were serviced
• fuel pressure set and steady via gauge at 28lbs
• New plugs, rotor, cap...wires appear to be in good condition
• installed a rebuilt 043 MPS (Bleyseng)
• Checked for vaccum leaks
• Engine runs at 325-350 on CHT gauge
• New cylinder head temperature sensor
• New air cleaner

Things I haven't done

• adjusted the ECU....as I understand it...this is only an idle adjustment mixture....although the motor smells maybe a tad rich at idle
• Have not played with the trigger points (stock bosch dizzy)

At this point I don't want to just start throwing money at parts. From what I've read, the trigger points can cause bucking and too rich running. When I saw Pelican wanted $175 for them...I didn't want to roll the dice????

The only other symptom worth mentioning, is when I first start the motor when it is cold, the idle hunts quite a bit....like 1000 rpm...not to sure what that is all about. I did install a oem thermostat and the air flaps are working correctly. After it warms up the idle is fairly steady but a bit rough.

Sorry for the long story....I need some ideas

[rjames]

check your relayboard. make sure you don't have any cracks on the underside causing sporadic cutoffs

My car was doing exactly what yours was until I replaced the relay board. It was working fine one day, and then the next it would buck unless at 3000rpm.


It's an easy thing to check if you can borrow a known good one.