1988 240 sedan is sluggish accelerating
 

ive had this issue since i got it and didnt think anything of it until i recently drove another 240 and realized mine had a clear problem.

its always had a cold start issue: when i go to start it for the day ive got to give it a little gas when it first starts up. one guy on here told me that could be a 5th injector issue, havent really looked into it.

after its started, it doesnt want to accelerate. id say it takes around 15 seconds to get up to 60, maybe a bit longer. once i get it up to whatever speed im going, it cruises just fine. but if ive got to speed up again, its just as sluggish like its being held back. this doesnt get any better throughout the day either, stays sluggish when giving it gas but cruises fine when i get it up to speed.

i thought it may be the timing and had my mechanic check it today. its perfectly in time so thats not the issue.

where do i go from here? injectors, fuel pump? it doesnt act like its struggling to get gas and the gas mileage has been great.

any help is very appreciated!

update:

just cleaned out the maf sensor and tried that with no change. it has the correct maf sensor in it and the maf sensor is working.

does it feel like its in too high of a gear, like its shifting up too soon? it would do that if the 'kickdown cable' has too much slack.

if you're cruising along on level ground at a steady, say, 30mph, just giving it a little gas should trigger a fairly quick downshift.

thanks for the reply pierce.

i dont feel like its a shifting problem. it does it from the start, its always sluggish no matter what the speed. once i get to whatever my desired speed is, it cruises just fine, its just getting there. ive always felt like its shifting as it should and my speed matches the tach. it doesnt ever feel like its shifting too soon or too late.

maybe your ignition is really retarded. LH2.2, you do have to set the base timing by rotating the distributor, and using a timing light. advance is done electronically so there's no vacuum or mechanical/centrifugal advance to worry about.

yeah my mechanic used a timing light and said it was dead on.

im kind of wondering if the converter is stopped up?

for what little its worth (about $0.02), our 87 240's converter lasted almost 400k miles. car was still running fine, but having trouble passing smog (California bi-annual inspection) unless the mechanic got it really really hot before the test, so the next time around, we put a new cat (and o2 sensor) in, and it passed like new.

now this car had never had any sort of engine problems that might have fouled the cat (like running too rich, burning oil, etc).

hmm. my daughters 87 240 (said 400K+ miler), earlier this year the center drive shaft bearing was frozen up solid and spinning in the rubber waffle puck that its mounted in, when we replaced that bearing, the car got a lot quieter and snappier

i havent noticed any excessive noise but i'll mention that bearing.

as for the converter, i suppose its easy enough to check by just dropping it. its worth a shot. i dont know what kind of shape it in. i know ive been in some cars that have a clogged converter and it wont get over 25 mph. then ive been in other that are just sluggish and feel like theyre being held back kind of like this.

another thought, possibly the throttle body or throttle control?

clogged up throttle body (not uncommon) tends to cause idle problems, not power problems.

re: throttle control, with the engine off, have someone slowly press the gas pedal to the floor and slowly release repeatedly while you watch.... make sure hte idle switch si clicking just as the throttle is fully released, and make sure the throttle itself is fully opening when the pedal is fully pressed. also, just before the pedal hits the floor, you should feel a 'notch' or 'cam' action in the pedal, this is in the transmission, and is the 'kickdown'. when the pedal is fully released, the kickdown cable that comes off the main throttle pulley, heading backwards and downt o the tranny, should have just a bit of slack, and the little crimp stop on the cable should be just a hair before the plastic dust cover on the end of the adjuster ferrule. if all that checks out, I think your throttle is fine.

make sure the vacuum hose to the fuel pressure regulator is good, its function is to increase the fuel pressure when there is LESS vacuum (eg, throttle wide open)

past that, I'm kinda lost. your mechanic could do a fuel pressure test, this requires disconnecting the fuel line that goes into the injector rail, installing a T fitting thats connected to a fuel pressure gauge, also the gauge may have a vacuum line with a T that goes to that same vacuum line I mentioned... the fuel pressure for LH injection should be 42-44 PSI above manifold vacuum when the engine is running. if the pressure gauge isn't connected to the vacuum, then I'd expect about 35psi at idle going up to ~43psi when wide open. if you want to do this yourself, you need a deluxe fuel pressure gauge kit that includes the T fittings for a Volvo as many american-etc cars have a schrader type valve already in place for doing these tests.

if your fuel pressure is low, it could be due to a failing fuel pressure regulator, or a clogged fuel filter, or weak primary fuel pump.

MY symptoms from said clogged filter and failing fuel pump were a fairly obvious stuttering loss of power at high RPM/throttle but your mileage can and probably will vary :)

we changed out the fuel filter when i got this 240, about a year ago. i kind of dont think its one of the pumps but its possible. im going to have it checked at some point.

however, i had my mechanic drop the converter today but before that i took it down the road about a mile (ive left it sitting since we cleaned out the maf last weekend). it rode better in that one mile than it has the whole time ive had it. i dont know what the vehicle sitting after cleaning that maf would do, but hand to god it accelerated much, much better for that short drive.

still, they dropped the converter and that made no difference.

so im wondering if a new maf would be worth while. if they were cheaper id go for it. i think for now ill just deal with what ive got. its still not perfect but it is much improved after cleaning that maf and letting it sit.

onto another problem, the ac has never worked in this thing and i had the heater control valve switched a few weeks ago because everything was working under the hood, just no cool air inside. so they changed that valve and it would switch from hot to cold, but just not cold air from the ac. so while they still had it in today, i asked them to check the freon while they were there. now for some reason the compressor isnt kicking in! but it was working just fine before so could there be something connected improperly dealing with that control valve? or maybe when they had the piece of the dash out it screwed up or disconnected the ac switch?

well, (from memory), the AC compressor control signal comes out of the dashboard, goes to a low pressure switch on the 'reciever/dryer' (looks like a beer can) in the AC plumbing under the hood, then from that switch to a 'high pressure switch' which is down low on the left side of the condensor on the radiator, and from there to the actual compressor. you can temporarily short the connections at either of these switches to see if the compressor fires up. you can put a volt meter on the wire from the dashboard, it should read +12V relative to ground if the AC is being told to switch on.

most 240's have a fairly primitive AC control, but the last couple years, they switched to the 740/940 manual climate control system, which is a little different. 88 would definitely be 'early style', with an AC knob on the dash that sets a duty cycle for the AC, what percentage of the time its on, from 0% to 100%.

an 88 had R12 from the factory. has yours been converted to R134A ? R12 was banned internationally due to ozone depletiion issues, R134a doesn't work as well in older system.

all the problems are fixed! (for now :))

the car is running much better like i said. cleaning that maf seemed to do the trick. right after it didnt but letting it sit a few days did something for it. no idea why. but yesterday i drove it a good bit and was able to take off on a steep hill with no problem and was actually able to gain speed going up hill on the interstate at 70mph. couldnt do any of that before.

as for the a/c, it ended up being a loose ground behind the switch. before i had the heater valve control, earlier this summer i had the blower motor replaced and they of course had to take everything apart for that. so evidently when they reassembled it, he didnt get that ground screw tight. so earlier in the summer it must have been just tight enough for that ac switch to work but driving it around a little probably knocked it loose. i also found another ground back there that wasnt connected at all. so i got all that connected and boom, cold air! :)

feels like a totally different car now. thanks for all the help pierce!