91 Q45: Will it still run if timing has jumped? Help diagnose this problem pleas

[cam76034]

Newbie here looking at a 91 Q45 with 230K on it. Will start, but runs rough like its only firing on 3 or 4 cylinders. No smoke, and I did slowly chug around the block. Slip and TCS lights are on the transmission too. From what I've read so far here, it could be injectors or plugs or coilpacks. Or, the timing chain guide issue. Which brings me back to my question, does this sound like a timing chain problem? Or something else?? Alternator?

[Q45tech]

Timing chains usually result in a locked up engine from bent valves on driverside.

Determine if it is actually running on 4 by feeling the 2 exhaust manifold heat shields................check valve cover mounted ignitor [ignition switching modules] connectors.

Consult tests, what does deale say it will only cost you $100 for diagnosis.

[cam76034]

Would it hurt to drive it ? (about ten miles) To get it to a dealer? I think this is a steal, the owner doesn't know & doesn't care what's wrong with it he just wants to get rid of it. We're talking 4-500 bucks for the deal, and the body is really straight and clean.

[Q45tech]

Why they make flat beds and $100 [or less] sure beats the damage you might cause.

Remember EVERY 15 year old Q [for sale] needs at least $3,000 to return to near new standards.

Based on roughly 50/50 parts and labor ............15-20 hours by someone and $1500 in new parts [junkyard or ebay is less but may not be available].

The most expensive quote we ever wrote up on an inspection was $11,000 on a 91Q without TCS that was driven to shop under its own power...............it was removed and driven 70 miles under its own power.

steering, suspension, transmission, drive shaft, diff, brakes, bearings, ac, hvac, injectors, LEAKS, rad, fans, water pump, alternator, battery, window regs, cruise, radio.........and a dozen other things.

That said we have bought some $500 Q that were rehabilitated by techs who spent maybe 25 hours of their personal time and found lots of used parts to make them almost perfect.............good enough to allow wife and kids to drive from ATL to Chicago multiple times for years.To my knowledge only shocks and brake pads, rotors, and a few suspension parts and tires need to be purchased new.............not to say they didn't drop the engine for R&R.......................we currently have 6 Q junkers to select parts from and usually end up buying another 6 per year for those purposes.

All depends on your and combo/friends/techs expertise.

[cam76034]

Thanks, like I said before, I don't know anything about Infinitis. Didn't even know what TCS meant, much less what the light being on might indicate. I take it the TCS and Slip warning light mean don't drive it?

[Q451990]

I know from experience that they can sometimes run after a timing chain guide failure - if it only jumps a couple of teeth. That's what happened to my first Q and I was able to pull her into a parking lot. My exact thought was that four or five injectors were dead - maybe a wiring harness? I noticed a lot of backfiring as well.

Anyhow, those lights don't indicate "don't drive it" - we're saying that just from the general way it's running. If you're hoping to save it, the best bet is to run it as little as possible before completing the diagnosis.

Good luck!

Heath

[trw2k]

For what it is worth...Prior to replacing the chain guides and realizing it had jumped timing ( zerothread?id=161331 ) my 91Q45 seemed to jump timing and then jump back. Sometimes it would run great and then other times it would hardly start and then run really rough. As I was cranking it sometimes it would seem to jump back to the correct position and run fine. When mine had jumped it would sound like it was running on a few cylinders short.Good luck