91 diablo

 

great site,just purchased my first diablo,when I was inspecting it I could hear a hissing sound on the drivers side right where the two into one pipe connector.The car drove fine on the initial test drive.

After getting the car home,i ran the car without the air filter assembly attached on the drivers side ,and after a slight rev the left check light came on and kind of bogged and then engine stalled, I installed the air filter assembly the light went on after starting up right away,yhen the light went off.what I have noticed now is the tail pipe on the drivers side does not have the pressure that the tail pipe on the passenger side has,i suspect this car needs a converter.also the car boggs down around 4000 rpms. any thoughts. thamks

Converter? The bogging and pressure could be related to fuel system. Do you know when fuel filters and pumps were replaced?

Converter? The bogging and pressure could be related to fuel system. Do you know when fuel filters and pumps were replaced?

thanks for the respond,i do not know I can try to change filters fuel,some times engine temp climbs as well upon acceleration,did happen on test drive with previous owner.but car drove fine

Congratulations on the purchase! I recommend spending a little money to have a professional look it over. It's best to start your ownership with a sorted car so that any future problems are easy to isolate. Where are you located?

Congratulations on the purchase! I recommend spending a little money to have a professional look it over. It's best to start your ownership with a sorted car so that any future problems are easy to isolate. Where are you located?

I,m in Toronto canada

thanks for the respond,i do not know I can try to change filters fuel,some times engine temp climbs as well upon acceleration,did happen on test drive with previous owner.but car drove fine

 

I just wasn't sure what you meant by "converter" though. Regarding the engine temps, do you mean "water" temp or engine oil temp or both? Depending on traffic and exterior temp and how you're driving, the water temp will fluctuate. Its not like most other newer cars where the water temp is able to stay pretty steady. If you're not in stop and go traffic and you're just cruising at reasonable RPMs, then you shouldn't be noticing much temp change once you're at operating temps. What temps are you seeing? Could need a coolant flush. Could just need to bleed the system. Are your fans on? Both of them? Would need all the details to give you a better answer. A lot of this stuff can be tracked down and corrected by you if you want to and have the time. Would save you some money over leaving it to an expert.

I just wasn't sure what you meant by "converter" though. Regarding the engine temps, do you mean "water" temp or engine oil temp or both? Depending on traffic and exterior temp and how you're driving, the water temp will fluctuate. Its not like most other newer cars where the water temp is able to stay pretty steady. If you're not in stop and go traffic and you're just cruising at reasonable RPMs, then you shouldn't be noticing much temp change once you're at operating temps. What temps are you seeing? Could need a coolant flush. Could just need to bleed the system. Are your fans on? Both of them? Would need all the details to give you a better answer. A lot of this stuff can be tracked down and corrected by you if you want to and have the time. Would save you some money over leaving it to an expert.

both fans work fine,water temp does not even reach 100, hovers below,car will rev to 6000 when standing still,i did add almost a gallon of anti freeze ,the bleeders are seized,both exhaust manifolds at roughly the same temp,the hissing sound on the right side of engine which is the left side of car gets louder and softer,on a normal car this is a sign of a catalytic converter clogged up,do you know how a stock muffler works on my diablo,does the exhaust exit on the opposite side of the inlet pipe , battery is putting out 13.2 volts,i forgot to mention that when the car starts to bog down there is a lot of gas smelling from the back of the car.could be an air pocket in around the coolant sensors.

From the time of purchase to having car physically with me there was no more than .5 of a kilometer from time of transport,

this problem started when air filter housing was removed as well as the drivers side wheel well, and the car revede up to say 3000 rpm to check for hissing sound,thats when emission light went on then the stall,then I started engine, the light was on left bank emission ,then 30 seconds later the light went off. Any thoughts

If the check engine light came on there should be a code stored in the ECU. Sorry, I'm not familiar with how to read the codes on a 91.

 

Can you take a picture of the y-pipe you are referring to? I think its the cold start air bypass.

 

If you suspect one side of the engine is running rich you can pull out the spark plugs and compare one side with the other.

 

A clogged catalytic convertor will eventually overheat. So be careful not to run the engine too hard until you are sure. Does a 91 have temperature sensors on the primary catalytic convertors?

 

both fans work fine,water temp does not even reach 100, hovers below,car will rev to 6000 when standing still,i did add almost a gallon of anti freeze ,the bleeders are seized,both exhaust manifolds at roughly the same temp,the hissing sound on the right side of engine which is the left side of car gets louder and softer,on a normal car this is a sign of a catalytic converter clogged up,do you know how a stock muffler works on my diablo,does the exhaust exit on the opposite side of the inlet pipe , battery is putting out 13.2 volts,i forgot to mention that when the car starts to bog down there is a lot of gas smelling from the back of the car.could be an air pocket in around the coolant sensors.

From the time of purchase to having car physically with me there was no more than .5 of a kilometer from time of transport,

this problem started when air filter housing was removed as well as the drivers side wheel well, and the car revede up to say 3000 rpm to check for hissing sound,thats when emission light went on then the stall,then I started engine, the light was on left bank emission ,then 30 seconds later the light went off. Any thoughts

 

I can't remember how the stock exhaust routes. You should be able to pull off your rear decklid and remove the exhaust heat shield and look. Sounds like you need to do that anyways and remove the upper coolant pipe to have the breeders tapped and rethreaded. Air pockets wouldn't sit at the thermocouples. And I don't assume you meant that was the cause for the fuel smell. Maybe you have an injector stuck open?

If the light goes out and it is running ok after that, then you should be ok. To read codes on a 91, turn the key to the accessory on position and back off 3 times. Then back to the accessory on position. All within a few seconds. Each check engine light will flash and you need to count the flashes. Its tricky because if there are multiple codes, then it will pause in between but it is sometimes tricky to tell when one is ending and the new one begins. The number of flashes pertains to a specific issue. Like 3 flashes means running rich.

Take a look at Lamboweb.com, there's great info about Diablo repairs, I had a 94 and yes on My 94 the exhaust exit on the opposite side (my car had 4 cats, primary and secondary and secondaries ones goes on a X, not sure about 91).

You guys are great,i tried the key code reader ,no codes .

 

This site is amazing for support to all lambo owners,i,m going to figure it out and let you know. Yanni

Hope it's something simple!

You guys are great,i tried the key code reader ,no codes .

 

This site is amazing for support to all lambo owners,i,m going to figure it out and let you know. Yanni

 

 

Go to daytona auto centre in Woodbridge they will sort you out. They are the best

Just finished removing the cats at work,i own a auto service garage ,the right side converter is rattling,outside cover is blue,does anybody have bypass pipes for sale. please let me know,anyways thanks for all the replies.

Either do that or just gut them! Quicksilver is most common I think.

 

Just installed by pass tubes ,car runs excellent,thanks for all the help from the other memebers

Glad it worked out!