Running rough troubleshoot help
#1
Running rough troubleshoot help
Help troubleshooting my ‘86 Euro N28/45 that has been in storage for 3 years. I haven’t used it much since about ’03, when I had previously stored it.
I did TB/WP 3 years ago, maybe 100 miles ago. In getting it ready now, I drained the varnish, replaced the fuel pump and filter, blew out metal lines, and replaced fuel lines, replaced vac lines and fittings (Roger’s kit) ,cleaned fuel injectors and rails, pulled and cleaned throttle body and maf, replaced rubber and hoses, cleaned and checked ISV operation, and changed (2) disintegrated connectors and new battery.
It starts easy and idles great. When I bring it to 1500 rpm, it begins to run rough. At 2K, it runs much rougher. Higher than 2K and the motor stalls out. It restarts great and idles. A quick press on accelerator and it dies. I can only gradually increase RPM to 2K, then the motor runs rough and stalls.
With a fuel pressure gauge on #1 rail port, at idle, it reads 25 psi. At 2K it reads the same 25psi. When I disconnect the fuel pressure regulator vac, I get 33psi fuel (at both idle and 2K rpm.) The idle vac at the regulator measures 17 inHG vac. Vac went to 18inHG at 2K rpm.
When I turned the car off, fuel pressure was 33psi, in 1 hour, the pressure has dropped to 10psi. Don’t know if it is related, but thought I’d mention it.
I am thinking low fuel pressure, but maybe some of you know better. When it dies, I still have 33 psi in the rail. What do you suggest I troubleshoot or measure next? I love the sound of the car, but want to go faster than idle!
Thank you for your suggestions.
Jim
I did TB/WP 3 years ago, maybe 100 miles ago. In getting it ready now, I drained the varnish, replaced the fuel pump and filter, blew out metal lines, and replaced fuel lines, replaced vac lines and fittings (Roger’s kit) ,cleaned fuel injectors and rails, pulled and cleaned throttle body and maf, replaced rubber and hoses, cleaned and checked ISV operation, and changed (2) disintegrated connectors and new battery.
It starts easy and idles great. When I bring it to 1500 rpm, it begins to run rough. At 2K, it runs much rougher. Higher than 2K and the motor stalls out. It restarts great and idles. A quick press on accelerator and it dies. I can only gradually increase RPM to 2K, then the motor runs rough and stalls.
With a fuel pressure gauge on #1 rail port, at idle, it reads 25 psi. At 2K it reads the same 25psi. When I disconnect the fuel pressure regulator vac, I get 33psi fuel (at both idle and 2K rpm.) The idle vac at the regulator measures 17 inHG vac. Vac went to 18inHG at 2K rpm.
When I turned the car off, fuel pressure was 33psi, in 1 hour, the pressure has dropped to 10psi. Don’t know if it is related, but thought I’d mention it.
I am thinking low fuel pressure, but maybe some of you know better. When it dies, I still have 33 psi in the rail. What do you suggest I troubleshoot or measure next? I love the sound of the car, but want to go faster than idle!
Thank you for your suggestions.
Jim
#3
Yes, it is a 32v twin distributor. I'll check the belt. Also, replaced TPS sensor. Will check temp sensor II today.
I think the fuel pressure is within the minimum limits, and was going to check the MAF next.
Is the vac at fuel regulator of 17" Hg OK?
Thanks!
I think the fuel pressure is within the minimum limits, and was going to check the MAF next.
Is the vac at fuel regulator of 17" Hg OK?
Thanks!
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#8
With disconnected MAF, idle oscillates between 750 and 900 rpm, motor sounds very good up to 2K rpm, then misfires.
When MAF is connected there is a very smooth, stable idle at 825 rpm. At 1500 rpm, it begins to misfire, becoming very rough at 2K. Above 2K stalls.
Is idle fuel pressures of 25psi (with 17" vac at fuel press regulator), and 33psi (with vac line removed) consistent with N28/45's? Can I rule fuel psi and vac out?
No visible cracks in distributor caps. Next step, I'll run tonight in the dark and look for wires arcing.
Any suggestions for the next troubleshooting direction?
When MAF is connected there is a very smooth, stable idle at 825 rpm. At 1500 rpm, it begins to misfire, becoming very rough at 2K. Above 2K stalls.
Is idle fuel pressures of 25psi (with 17" vac at fuel press regulator), and 33psi (with vac line removed) consistent with N28/45's? Can I rule fuel psi and vac out?
No visible cracks in distributor caps. Next step, I'll run tonight in the dark and look for wires arcing.
Any suggestions for the next troubleshooting direction?