1988 Toronado Shudder/Misfire

[Tpsullivan84]

Greetings from the Windy City,

I've ran out of options as to where to turn for this, and was hoping someone here could assist-
88 Toronado Trofeo w 38k miles. Plugs, wires, fuel filter & regulator, IAC, coolant temp sensor & coil pack all replaced recently, and MAF cleaned. Fuel pump tested fully functional. Multi is reading 14.3 ohms on each injector. Don't see any issues with vacuum either.

Issue: Car idles poorly and stumbles intermittently upon takeoff. If pushed, it runs smooth as glass. It got to the point last week though where the oil pressure would drop and the car would stumble and miss regardless of acceleration. Thought it was the fuel pump, but a new coil pack remediated this. Now it's back to just a shoddy idle and occasional stumble- square one. My mechanic can't figure it out, I can't seem to make heads or tails and the FB groups haven't been much of a help.

Does anyone have any thoughts or suggestions? No CEL and it doesn't exhibit the stalling symptoms like my 89 Riv when it was a crank position sensor, but I guess it could be that? Would the harmonic balancer cause these issues? I don't want to keep throwing money at it though for "maybes". Any help is much appreciated!

Thanks!
Tim

[Otto Skorzeny]

That car is newer than I'm used to working on but here are a couple thoughts.

Have you checked the timing? Can the timing chain and sprockets be worn or stretched/damaged?

How about timing advance? Does that car have a vacuum advance?

[Tuco]

Also, with only 38,000 miles it’s obviously been sitting a while. Possibly the injectors are clogged.

Like Otto this is a lot newer car than I’m used to working on.

[romcoby]

Could be a bad EGR valve also.

[Schurkey]

COULD be this. COULD be that. COULD be something else.

CONNECT A SCAN TOOL, look at the data stream. You might even find stored codes which are sometimes helpful.

VERIFY FUEL PRESSURE.

Between those two things, you should have enough clues to track down the problem.