Loss of power high rpm 87 FI

T

TheoF

Daily Driver
Hello,
I hope everyone is doing good,

After a successful brake and clutch master replacement the x19 is back on the road. 😁

Now im trying to fix the little defect that there are to fix, starting with the loss (or at least i feel like it) of power in the higher rpm range.
It's not a sudden power loss like hitting a wall, but it feel like its missing power and i shouldnt be in this rpm range, even though i keep seeing people mentionning x19 being the happiest in the 4-7k rpm range..

I did some test and found some failure point along the way, including a bad injecor and the spring in the distributor missing, but nothing have changed..
-Fuel pressure engine off at 34psi
-Fuel pressure engine running at 28psi

- Compression test gave 135, 135, 122, 135. So might be something going on with cylinder 3, i will check valve clearance but i doubt it will make a significant difference. (I might be wrong too)
- Timing was checked multiple time and i doubt thats the issue, however my belt is a little sloppy, not sure why..
-Tested mechanical and vacuum advance on distributor, both are working.

Im not sure what to check now.. or even if thats not normal..
Here a link to a video i made, first and second gear, we can see in the second gear after 5k is not as fast.

Thank you 😊
 
Welcome to Xweb. We may have interacted on FB.

FI US market X’s were set up to meet our emission standards. Among the differences from EU/ROW cars were reductions in compression ratio which was done with lower compression pistons and a head with a compression relief as well as smaller valves. Additionally the cam is set up for emissions which tends to reduce power at high rpm and make it less responsive at higher rpm. They tend to ‘run out of gas’ above 6k so to speak. The US exhaust system is terrible as it is a four into one system with a rather convoluted path to the catalytic converter.

In addition to the good data you have provided, I would look at the ignition system. Make sure it is set up for 10° BTDC. Verify the distributor cap is intact as there have been a number folks finding the carbon pin missing that makes contact with the top of the rotor. Also look carefully at the rotor, it is a resister rotor and the resistor can burn out.

Doing a valve adjustment won’t hurt anything.

I would consider pulling the injectors to have them cleaned and balanced.

A number of folks here have bought the EU cam and been very pleased. This cam works well with the FI system.

If you end choosing to rebuild the engine in the future I would acquire the EU/ROW parts for the cam, pistons, head and the exhaust system. The FI system will automatically compensate for the improved ability to pump air.

Others will likely chime in. Good luck.
 
kmead said:
Welcome to Xweb. We may have interacted on FB.

FI US market X’s were set up to meet our emission standards. Among the differences from EU/ROW cars were reductions in compression ratio which was done with lower compression pistons and a head with a compression relief as well as smaller valves. Additionally the cam is set up for emissions which tends to reduce power at high rpm and make it less responsive at higher rpm. They tend to ‘run out of gas’ above 6k so to speak. The US exhaust system is terrible as it is a four into one system with a rather convoluted path to the catalytic converter.

In addition to the good data you have provided, I would look at the ignition system. Make sure it is set up for 10° BTDC. Verify the distributor cap is intact as there have been a number folks finding the carbon pin missing that makes contact with the top of the rotor. Also look carefully at the rotor, it is a resister rotor and the resistor can burn out.

Doing a valve adjustment won’t hurt anything.

I would consider pulling the injectors to have them cleaned and balanced.

A number of folks here have bought the EU cam and been very pleased. This cam works well with the FI system.

If you end choosing to rebuild the engine in the future I would acquire the EU/ROW parts for the cam, pistons, head and the exhaust system. The FI system will automatically compensate for the improved ability to pump air.

Others will likely chime in. Good luck.
Click to expand...
Yes I remember about the carbon nub haha

So I guess the thread I saw was about EU car then..
I might start to gather part to upgrade, we might even have a eu cam in our basement

I just wanted to be sure the engine was supposed to act this way, because I changed head gasket last summer and I wasn’t sure of the power it had before.
Thank you for clarifying
 
kmead said:
Welcome to Xweb. We may have interacted on FB.

FI US market X’s were set up to meet our emission standards. Among the differences from EU/ROW cars were reductions in compression ratio which was done with lower compression pistons and a head with a compression relief as well as smaller valves. Additionally the cam is set up for emissions which tends to reduce power at high rpm and make it less responsive at higher rpm. They tend to ‘run out of gas’ above 6k so to speak. The US exhaust system is terrible as it is a four into one system with a rather convoluted path to the catalytic converter.

In addition to the good data you have provided, I would look at the ignition system. Make sure it is set up for 10° BTDC. Verify the distributor cap is intact as there have been a number folks finding the carbon pin missing that makes contact with the top of the rotor. Also look carefully at the rotor, it is a resister rotor and the resistor can burn out.

Doing a valve adjustment won’t hurt anything.

I would consider pulling the injectors to have them cleaned and balanced.

A number of folks here have bought the EU cam and been very pleased. This cam works well with the FI system.

If you end choosing to rebuild the engine in the future I would acquire the EU/ROW parts for the cam, pistons, head and the exhaust system. The FI system will automatically compensate for the improved ability to pump air.

Others will likely chime in. Good luck.
Click to expand...
Theo,
I second everything Karl has mentioned here. While my X has a carb, Fiat's pollution control philosophy/tactics essentially remained the same for FI cars. I removed all my emission controls, (save the passive ones) and have all of the Euro parts listed above, with 2 additional mods....higher compression pistons and a header. I can honestly say the difference in the improved performance (over the stock engine) has transformed the car. Even when strangled by the Smog Squad, these cars were always fun to drive. However, (while still not fast by modern standards) I have no problem keeping up with traffic, and finally have enough shove to match the awesome chassis and fully exploit the amazing handling these cars have. It is no longer a "hairdresser's car" but a "proper" sports car. I also have completely stock suspension with (God only knows how old) original components! Another thing worth noting- is the missing distributor spring may have been intentional to get to max advance sooner in the curve. Good luck making your X "your X" !!!
 
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