'83 Mondial QV Losing Power A bit of an issue with an '83 Mondial QV. When driving above 4,000 rpm, the bar seems to bog down, basically losing power. The car just had a new fuel pump installed, new fuel fuel filter and crank sensors. There is spark on all 8 cylinders. Timing is perfect. Injector issue? Also, how many relays are there for the ECU? Thanks!
None -- a 1983 US or Euro MondialQV is K-Jet without Lambda and doesn't have an injection ECU. Give a little more background -- is this a "new" problem (i.e., it was OK and then suddenly became bad, or has it always been bad during your ownership)? If it is a fuel-based problem, I'd be more suspicious of the FD rather than the injectors. Do you have cats installed? A partially blocked exhaust would run OKish at low RPM and have trouble at high RPM -- just a thought...
=============== I purchased the car recently, and went right into the shop for a major service and other tidbits. As far as I know, this problem did not occur previously. Cats are installed, will check for blockage in exhaust. Can you expand on potential fuel delivery issuses? A new fuel pump was just installed. Thank you!
Having a new fuel pump and fuel filter are good things for ensuring that the supply fuel pressure is OK (but it should probably still be measured/checked), but it's the FD + Airflow metering unit that essentially "measures" the amount of air entering the engine at a given RPM and then (mechanically) determines how much fuel to add for that amount of air. The K-Jet/KE-Jet injectors are really just on-off pressure relief valves that open up at given pressure so IMO it's fairly unlikely that they would be OK at a low fuel flow rate (low RPM) and then bad at a high fuel flow rate (high RPM). Now for the bad news -- since you just had the major service done, it's possible that a cam (or cams) is (are) mis-timed. If the problem is/was immediately present when you picked up the car from the major service, I would put some likelyhood on this. Of course, checking the cam timing. measuring the fuel flow rate exiting the injectors, and checking the cats for a blockage are not trivial tasks so please make your own decisions, but, IMO, IF the bad running is directly tied to the major service you should have some recourse with the Shop that performed the major service -- good luck.
Funny - I pushed down on several relays to make sure they were connected well, and oila! Fixed. Car is as smooth as it should be. I pressed on several relays, so I can't even tell you which one it was.
The only good Gremlin is one that goes away The only relay in the passenger compartment on your '83 Mondial QV related to the engine running is the fuel pump relay -- and that's usually a go/no-go situation so I'm surprised that your pushing actions could really directly change anything. The good news is that with proper operation verified as possible you can scratch any cam timing problem off of the possible trouble list (as it isn't something that could heal itself). In your initial report you stated only a lack of power at high RPM, but now you say "Car is as smooth as it should be" -- does this mean that, in addition to lack of high end power, it was also unsmooth when it was in the "bad" condition?
Perhaps "smooth" was a bad choice of words. When the revs got to 4,000 rpm or so, it seemed like the car was sort of choking. Under 4,000 the car pulled very smoothly.
I don't recall if you mentioned that the problem came up when the engine was cold or warmed-up. If that's of any help, I had a similar condition with my 85 308 QV. It performed great while cold but when warmed-up, I couldn't get more than 4000 RPMs. It felt like it was being strangled!!!! After eliminating all the usual possible problems areas and (while at it) replacing this and that, it finally came down to the Warm-up Regulator. Spending another $400 solved the problem. Hope that helps.
