Cuts Out at 45mph

[lostcausegarage]

My 91 Metro 1.0 Auto cuts out around 45 mph steady throttle when warm. I checked the fuel pressure and it reads 20 psi. To me it feels like the ingniton is cutting in and out. There is not a real pattern but the cutout will last for .5 to 2 seconds then will stop for a while but does it 5-15 times within a mile. It is not a miss but rather it feels like the whole ignition shuts off. Any suggestions??

[doug2060]

This issue could be caused by many things. Check your wires and spark plugs for wear or damage, distributor too. You may not be getting adequate flow through the catalytic converter. You could have bad cylinder compression. There are so many things it could be. Start with the plugs and wires first...

[Johnny Mullet]

Doug is correct and there could be many things related to the problem

Is the check engine light on?
Check the coil and coil wire for corrosion also.

[Crvett69]

if it cuts out worse faster you go sounds like fuel pump or fuel filter. may not have enough flow

[doug7x]

Originally Posted by Crvett69

if it cuts out worse faster you go sounds like fuel pump or fuel filter. may not have enough flow

check your fuel pump relay...could be bouncing contacts, among (like everyone else said) MANY other things, but I would lean towards a bad (part time) electrical contact somewhere, maybe a bare wire grounding intermittantly, (I'm having a similar problem with my '91 XFI fuel pump), rather than something mechanical....post everything you try, & the results...maybe we can help you narrow it down...good luck

[lostcausegarage]

The car now runs fine except for an occasional code 51 for the egr. I'll tackle that next. Here what I think fixed it. After I adjusted the tps it stopped cutting out. What I think was happening was it was telling the ecm that it was at idle when it was not. I noticed it only acted up when going down hill or level (less throttle) and never did it going up hill (more throttle).

The whole story on the car is I bought it with a blown engine and swapped in a used one so I never knew how good it ran before. I did reuse all the original parts from the original engine because the "new" engine is a 92 and I have a 91.

Thanks for all your advice guys!

[Johnny Mullet]

Originally Posted by lostcausegarage

The car now runs fine except for an occasional code 51 for the egr.

Don't replace the EGR valve. Clean the EGR ports that run through the head and clean the valve real good.

[lostcausegarage]

Latest update:Cut-out at 45 is still gone after the tps adjustment. Cleaned the egr valve and now code 51 is gone. The latest glitch is I have an idle surge when I coast down from 30 mph or less. I'm guessing it's around a 200-300 rpm surge. Once I come to a complete stop the idle settles down. Other than that all is good. My first tank of gas is going to average 39-40 mpg. Not too bad considering it's and automatic.