I got this car a few weeks ago after it was sitting for almost 2 years. It would start right up and drive but if you punched the pedal, it would fall flat on its face. I changed plugs, wires and coils. set TPS to proper range, got the check engine light to go away but it still wont rev. Verified vacuum getting to ecu, both coils are firing but if you take it up slowly it'll get to 4500 before starting to break up. Any idea what would cause this issue? Other thing I noticed is that its idling a tad high, around 1000rpm

 

Just spittin' in the dark here, but take off the air filters and visually watch if the butterflies open evenly and fully.

 

Fuel supply.

 

Last owner changed filter just before I picked it up but I'll pull it again tomorrow and see if its clogged from recent driving

 

There aRe two. One behind the spare wheel and one in the lower sump tank. That one is never changed but should be done regularly as it accumulates loads of crud.

 

As far as I know, the 92 only has the one under the car, there is no surge tank on these. My 88 has the one behind the spare tire.

 

You need to approach this problem in a methodical way. Test each system Ignition and Fuel one at a time. Verify each is operating correctly before moving on.

Does it idle smoothly, put your hand near each exhaust pipe and the stream of exhaust should be smooth, NO pulsing.

 

Do these connectors look correct?
changed filter, old one was full of red stuff, still won't rev. Other thing I just noticed is that it idle hunts shortly after cold starting but settles at 1100 after 5 or 6 swings. Running out of ideas...help

 

That plug with the loop back, the black one is the strategy link and should only be installed when running premium fuel.

Ideas are NOT going to fix your problem, you need to work through each system ONE at a time.

Did you put your hand to each exhaust while the car was idling and if so is the exhaust stream constant NO pulsing? if this is good then I would assume the injectors are ok.

A miss or 2, can be difficult to pick up especially for someone not familiar with a V12.

If it is not a constant stream of air out one or both of the exhaust pipes then we can go further into identifying which cylinders are not firing.

 

I've got premium in the tank now so I'll leave the connectors alone. Honestly with my hand over the tailpipes I think I feel pulsing on the right side but it's not blatantly obvious since there's a strong exhaust stream. I'm gonna go over all the stuff I touched to see if I left anything loose since the rpm swing is something that started after I did the tune up. I checked tps early on and didn't find any dead spots but will check again tmrw to make sure I'm still ranging from. 32 ish to close to 5v. Would plugged cats contribute to these conditions? I have a noid light so I'll check tmrw and make sure all injectors are getting signal and also see of there is any change when the injector is unplugged. I guess I'm still leaving towards this being a system issue and not a specific cylinder since it just dies off and if it was just one cylinder, it would still build rpm but slowly

 

Which filter was full of red stuff?

 

The fuel filter is what the red stuff came out of. No chunks just red fines

 

Plugged cats could contribute to the problem. You guys in the USofA got cats in the down pipes, a lot of folk remove these as they have been known to cause issues.

Dirty injectors could also cause this problem as could a weak spark.

Pick one place to start and fix everything you find. You could start at the injectors or the down pipes. Do not worry about the hunting idle yet as it is most likely not related to your reving issue.

 

Rust.

Not unusual on old cars, doubly not unusual on old cars that have been in storage, triply not unusual if stored with less than a full tank of fuel.

There might well be a number of issues at play but I think cleaning the tank and fuel system is in your future.

Cheers
DD

 

Red fines.

I don't know these. Red vines are candy. Kind of rubbery and would be very bad for the fuel system. what exactly came out of the fuel filter?

Assuming red particles in fuel drained from the filter, then the sump should definately be cleaned out and get a new internal filter as well. Even if the tanks are rusty, you should be able to resolve any starvation just by clearing the sump and replacing the filter. For a while at least.

If it's not fuel then I'd go to the ignition.

 

I'm going to hook up a inline pressure gauge off the threaded fitting that goes to the Rail and see if pressure is dropping off. Its the later style system so no surge tank, just main tank with intank pump unlike my 88. I may pull pump to see if the sock is clogged if pressure is dropping off. When I loosened the back nut on the filter, the liquid that rushed out was very red, I had a white pigmat on the floor below and where the fuel hit, it left a dark red stain, nothing large enough for me to pick up just lots of red dust suspended in the fuel.

 

so after realising that none of the fuel connections on this car are normal, I sliced the new crossover hoses that I just installed and put a tap there. Ignition cycles a few times and pressure got up to 40psi but once startedit dropped to 32. Tried revving and it went to 20. Shut car off and it held 20 so I'm assuming the regulator is still doing something. Any tips on removing the tank?

 

Spent labor day laboring on the 92, got the fuel tank out, what a PITA. pump screen was covered in red crud so I think the pump itself was coming apart. some minor rust on the outside of the tank that im going to scuff and spray eventually. Ordered new fuel pump, went with the $43 dollar one from rock auto. " while I was under there and had the car on the quick jacks, I dropped the rack out and changed the tower seal and " while I was at it, I went ahead and ordered new bellows and tie rod ends as these were shagged out. All this on a car I'm trying to get rid of but I've learned from experience that once you start telling people all the issues a car has, price soon plummets. And if I didnt have enough going on, hurricane Irma looks like she wants to pay us a visit at the end of this week, that wont be fun as I have 5 cars right now and only a 2 car garage...gonna be a few short straws drawn for who gets to see the storm from outside.