this is an update with more information from my earlier post.

i'm really confused on these symptoms, my first rex/regina car.

i checked the archives, but couldn't quite pinpoint the problem.

i'm hoping for some ideas today so i'll have time to go to the junkyard while they're open. got to get back to houston by monday.

1. rough idle.
2. warm start, need to pump the gas pedal, cold start, starts without pumping, but idles rough, but when warms up, the car dies.
3. once warmed up, need to keep high idle or will die.
4. black soot on sparkplugs & o2 sensor (new o2 sensor). cleaned them but still same symptoms.
5. when trying to drive, must pump gas pedal many times to drive from stop light.
6. can't maintain normal idle, dies. when i remove the connector at throttle body switch, car doesn't die, but has high idle, when i put the plug in, the car rpm goes to normal rpm, but dies.

i swapped out the tb with different switches, but no change in the problems.

7. engine light and code for o2 sensor (2-2-1)
8. since the car runs at high idle with the tb switch connector off, i don't think a problem with fuel pump & filter.
9. when i drive to a light or come to a stop while in gear, i have to put it in neutral and keep a high rpm and then put it in gear to drive off. it cannot drive from normal idle, can't keep normal idle.

10. when starting the car at cold start, the car's idle pulses, swings up and down (700-1100 rpm).

i checked the fpr--diaphragm not broken.

the car ran fine on the way up to dallas from houston. i was driving slowly in a parking lot when the car started dying. i had to restart the car and pump the gas pedal to keep it from dying.

thanks for all and brickboard. i hope i provided enough information.

regards,
byron golden
86 245
92 245
94 944
92 244 parts car

all,
i had a split vac hose connection at the map (manifold air pressure sensor).

after failing the first inspection because of high nox, i replaced all my vac hoses in the engine bay.

the map sensor has a vac connection that is bigger than the plastic hose to the intake manifold. i used a vac hose that fits the smaller hose, but forced it onto the bigger vac port on the map.

it worked until yesterday, when it split. since i replaced the hose, i didn't bother checking that connection.

just to check for vac leaks, i pulled the map vac hose to the manifold off and sucked on it. well, it didn't seal/close. so the map diaphragm was split or the hose split.

it was the vac hose. cut off the split part and put it back on.

now the car runs normal.

thanks for both of your replies. i hope this helps others in the future.

i'm still learning diagnostics on these rex/regina system cars.

thanks as always & regards,
byron

Did you replace the O2 sensor with the unique Regina type?
A Bosch type sensor will not work right.

Volvo # 3547445-1
NGK/NTK # 25003


--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

hello bruce,
thanks for your reply. yes, it's 25003, bought from amazon $109.

btw, line me up as a believer on the 240 advance plug for passing inspection.

i had my doubts at first, but i do it every time for inspection of my 86.

regards,
byron

If the O2 sensor is correct, perhaps you have a vacuum leak around the intake manifold; tighten up the manifold bolts and see if there is a change; if not get the engine to run and spray carb cleaner/propane/WD-40 around the gasket, a change in rpm would indicate a leak and you may need to replace the gasket.

thanks ladson,
it passed inspection a second time. the first time it failed, i did check vacuum leaks and put on new rubber vac hoses. and i checked the manifold too.

things may have changed after a long, fast drive about 75-85 mph sustained speeds.

i will probably try replacing the fuel filter and pump, brought a spare pump and sender setup with me.

i've had bosch fuel pumps fail away from home before.

if you can think of anything else, please write back.

regards,
byron

Filter and pump problems usually show up at high power demands on the engine. I recently replaced my fuel pump on my '73 Datsun 240Z turbo track car because it picked up sand from the bottom of the tank and became intermittent. Before you change them out, check that your idle air control isn't sticking...perhaps a cleaning will fix the problem. It should work smoothly.

thanks ladson,
i did clean the iac after it failed inspection the first time. i have a spare and i'll put it on next.

i changed out the fuel filter, which i needed to do anyway...no affect...no surprise.

i thought about maybe the new o2 sensor being defective...i doubt it, but i'm swapping out parts cheapest first.

i'll do a search for a local, used o2 sensor.

i don't think these ecu's go out.

i hope it's not mechanical, perhaps a slipped timing belt...may have to check that.


thanks,
byron

Check the ignition system to see if you are losing spark somewhere; My '97 960 has coil over spark plugs ignition and I haven't had any problems; however, if yours still uses a diz, check for cracks in the cap rotor, etc. If you have COSPs, check for signs of carbon burns at the high voltage connections; bad wires and weak spark; lastly take a compression check with and without oil in the cylinder to check the condition of the valves. BTW,the chance of the ecu being bad are slim because the unit is very robust.