Quit running while hot

[jcc3inc]

Good Afternoon,

'97 LeSabre with 90K miles on it.

Yesterday we went to a wedding, driving about 45 minutes on the freeway at 65-70 MPH, A/C on. On our way back, after getting off the freeway and waiting at a stoplight, the motor ran very poorly - almost no acceleration. After driving maybe 3 miles in 30 MPH traffic with A/C on it quit at another stoplight, acting like maybe a fuel problem. We opened the hood and sat for 10 minutes "cooling" and it started right up and got us home.

This morning I checked fuel pressure and it was OK. Removing the vacuum line on the fuel pressure regulator raised the fuel pressure from 40 PSI to 50, so I assume the pump is still OK. I did this at fairly high RPM.

About 1000 miles ago it quit on the freeway, problem was a clogged fuel filter; had a shop replace it and we got home OK.

Two other observations:
(1) It has been missing under load so I replaced the plugs, and noted the originals were in surprisingly good condition; did NOT replace the wires. There has been no discernable improvement with the new plugs.

(2) This morning I ran the engine at higher speed, and at about 4000 RPM, it
would go no faster with intermittent hesitation or jerkiness limiting the speed, to 4000 RPM. When I tried my 91 Reatta to look for RPM limiting, there was no sign of being limited at 4000 or 5000 RPM.

Am looking for ideas! Thanks,
Jack C.

[maxwedge]

The rpms on an obd11 car are 4k limited in neutral. Your original problem could be a fuel pump issue when run under extreme conditions or an ign problem for the same reason, the only way to tell is if if starts spraying carb cleaner into the intake, or check for spark when it won't start, basic diagnostics.

[jcc3inc]

Just a FYI:

The error codes showed an EGR fault; possibly it was hanging open or had dirt under the valve seat. At any rate, I changed it with and it seems that there is no problem. My friend says he has seen EGR problems causing the engine to not run; it seems logical that excess exhaust fed into the intake at idle would cause the engine to quit.

After more operation, I'll report back on the results.

Regards,
Jack C.

[maxwedge]

I don't agree, the egr is not going to cause a no start, stall and no start condition, I wish you well, keep us in the loop.