As stated in the title. I've got an 85 Euro that seems to run out of steam or stumble a bit above 4,000 RPM. Any suggestions as to where I should begin to look for the problem? The vacuum system has been smoke tested and is tight. The fuel filter is new. I don't know the full maintenance history of the car. Any help is appreciated.

 

load AND no-load?

fuel pressure gauge would be useful in diagnosis

 

Has the car been Federalised with an add on lambda box ?

 

Yes, I need to get a gauge. It will rev freely unloaded. The problem occurs under load only.


It was but it wasn't fully hooked up so I disconnected it. This problem was there before I disconnected it and remains after as well.

 

When mine decided to behave similarly it was a combination of a bad coil and 2 bad ignition wires (all 20 years old). I changes both coils and all 8 cables and problem went away. Good luck with yours.

 

Hi Fabio, was your LAMBDA box black? If so, how did you disconnect it? I have an 85 Euro as well and trying to get rid of that box.

 

You need to check the exhaust CO (before the cats, if they are fitted) and set it to 1.5%.

 

Sounds like ignition. The weak higher rpm - is it studdering or uneven? Or just... weaker?

 

I would consider a rebuilt MAF, new plug wires, and inspect the dizzy to make sure its timed as well as checking the cam timing.
My 84 Euro ran crappy till a new MAF was installed and new wires and timing of the dizzy was corrected.

Also check the grounds on the engine for the injection system
Replace the fuel filter,
install new spark plugs, autozone has them Bosch#7900 silver tips 1.99 each WR7DC

Adding an X pipe does wonders for performance

 

I just disconnected the wires. I did it while the car was running so that I could hear if the engine had any change. It didn't so I just left it off.

Is it possible to do this with a wideband instead of a CO meter? I don't have a CO meter.

It pulls hard and then just kind of stops pulling at 4k rpm

Thanks, I'll check the plugs and wires. I already changed the fuel filter. As for a new/rebuilt MAF...not gonna happen. I'm selling this car so that I can focus on my two main cars ( the 84 widebody and the 82 turbo ). I am getting rid of this car and a 78 euro widebody ( the Code Red Car ). 4 cars is too many for me. I don't have the resources of time or money to make all of them as nice as they should be so they are all suffering to one extent or another and it's taking forever to finish one. I'd just like to get this one running really strong before I sell it but dumping money into a MAF isn't in the budget right now. I'd rather just sell it for less $$ if that's what I gotta do.

 

Faulty rev limiter on the distributor rotor?

 

Well if it really revs happily and strong at 5K rpms with no load and then struggles under load, you have to consider some sort of mechanical binding.

(assuming a 5 speed) Now the question is every gear struggling at 4000rpms or just 1 gear, in other words is it definitely that rpm number regardless of gear or is it really at a certain MPH speed?

Things I can think of to rule out are TT trouble, ABS system kicking in, or even TBF (in a 5 speed) under the load.






Isn't the auto the only one with the vac line to the brain itself?

 

No they all have that. And what do you mean TBF? It's a 5 speed so no thrust bearing issues t worry about. That's not really an RPM related thing anyway as far as I understand.


Does anyone know what would happen if someone took a "performance" chip for a US 85-86 and put it in an 85 LH Euro? The only reason I ask is that a friend of mine said that he gave one of those chips to the previous owner of this car and he asked if that chip was in it. I haven't checked yet but is that even possible?

I really just need to start digging into this thing. I think the fuel gauge is first on the list to verify fuel pressure.

 

Yes, you could use a Wideband before the cats, set the MAF for 14:1 at warm idle.

 

I understand that TBF is an auto problem, that's why I worded my above post the way I typed it. But I kinda remember reading once a long time ago that there had been an occurrence in a 5 speed. Been reading threads here for 11 years.

Just trying to figure out the problem given the odd symptoms. Are the vac lines routed correctly? That vac line to the brain is how it understands load, I believe.