joes-92

92 hatch, d15b7, 170k miles
aftermarket i/h/e, new dizzy, wires, map sensor, thermostat, running p06 ecu

so my d15b7 was running rich for a while. after much searching i found that the thermostat was missing completely(from previous owner). i also had a bad bucking problem at low throttle. bucks violently in any gear under 2-3k rpm. i did notice a lil oil on the plug threads. recently replaced the top and bottom orings. now for the questions...

1. i reset the timing while the thermo was missing. now that i installed the thermo, do i need to re-time?

checked motor mounts(and even re-installed the ac bracket and torque mount). i am running the burnt plugs from before the thermo. i DID clean and sand paper them. i didnt want to put my new plugs in until i determined it was no longer rich.

2. that being said, could the fact i timed it while it was running open loop cause it to buck still? i am at a loss trying to stop the jerking/bucking. idles around 1k, seems steady enough.

and as always, any help or guidance is greatly appreciated.

joes-92

bump

*update*

after a week of driving my spark plugs havent been fouled, so i put the new set in last night. still getting the bucking.

rovafa2002

Change fuel filter, distributor cap and rotor and wires, might want to check your air filter too.

joes-92

Sorry, should have mentioned...
Brand new dizzy, wires and my short ram is about a month old and is still clean. I'll try the fuel filter.

I actually drove it about 45min on the hwy yesterday(avg of 60 mph). It overheated at the first light I came to. Me thinks it had a blown hg and the po removed the tstat to sell me a car that doesn't overheat. Couldn't see any visible leaks and both upper and lower hoses were scorching hot and very bloated. i managed to get them temp down by turning on the fan(was sitting at a red light). then with the fan running, i tried to take off on green and i got a cel and the rpm's started surging. being in traffic, i turned off the fan, then the car completely and restarted. cel and surging was gone after restart.

Could a blown hg cause the bucking? Do I need to reset the timing and ecu?

joes-92

please advise, not ready to swap the b in yet. my dd truck(v8) is killing me on gas and id like to drive the hatch...

grumblemarc

iTrader: (4)

I'm going to suspect timing. Both mechanical and ignition. You never said if you did one or the other or both. The overheating could be a sign of a headgasket problem. You can perform a pressure test, compression and/or leakdown test to verify. Do not run without a thermostat OR with it overheating.

joes-92

we did ignition timing only. mech timing is the checking of the cams to crank position?? sadly i ran it quite often before i found the missing tstat... ran super rich