Full Version: Low rpm stumble
I had a Crane Optical, which recently died. I have replaced it with a set of points and condensor from my FLAPS (non-Bosch). The car runs fine except for a some stumbling at low rpms. It seems to struggle to get to 1800, then takes off as normal. I've double checked my point gap and timing. Any ideas?
non-bosch is your first problem, and it can be a bog problem.
The real parts cost under 15 bucks....get bosch
RIch
The real parts cost under 15 bucks....get bosch
RIch
OK, I've replace the points and condensor with Bosch parts and still have the low rpm stumble. Even out of gear and giving it a little gas, it seems to struggle to 1800. After that it runs fine. I've double checked the timing, fuel pressure is correct. What else can I check?
FI or carbs?
Rich
Rich
2.0, Djet
Three things to check and set.
Fuel pressure...get a gauge to test it inline before the pressure regulator.
Check when the car is cold, and again when its hot.
If it changes when hot and goes down...increase it by turning the bolt on the end of the pressure regulator and set the pressure to 28-32 when hot.
Vacuum lines (I get sick of people that claim that this wont affect the car...it does, it does create a low idle issue)
Check them and clamp them if you have any potential leaks.
If you have the knob on the top of the ECU...where is it set?
This is idle enrichment and if its cranked up to the max...you flood at idle.
and finally, the TPS
It needs to be set in a specific position, no other.
It is only adjustable because the switch is used on alot of other cars..volvo, merc etc.
So, open the cover, clean the gold contacts with di-electric cleaner and set it like the picture at idle.
Rich
Fuel pressure...get a gauge to test it inline before the pressure regulator.
Check when the car is cold, and again when its hot.
If it changes when hot and goes down...increase it by turning the bolt on the end of the pressure regulator and set the pressure to 28-32 when hot.
Vacuum lines (I get sick of people that claim that this wont affect the car...it does, it does create a low idle issue)
Check them and clamp them if you have any potential leaks.
If you have the knob on the top of the ECU...where is it set?
This is idle enrichment and if its cranked up to the max...you flood at idle.
and finally, the TPS
It needs to be set in a specific position, no other.
It is only adjustable because the switch is used on alot of other cars..volvo, merc etc.
So, open the cover, clean the gold contacts with di-electric cleaner and set it like the picture at idle.
Rich
I've checked the TPS and filed the TPS reports. Adjusted the valves. Checked the dwell and timing yet again.
What else can be causing this?
What else can be causing this?
Have a coil you can swap out? Just replaced mine and made a world of difference.
QUOTE(blitZ @ Aug 19 2009, 02:20 PM) 
What else can be causing this?
What does your engine harness look like?
I needed 3 spare harnesses to make one good one for my 1.7L. The wires get brittle, especially just inside the thick plastic shielding.
I had to cut the thick plastic back about 1"-2" only to find a whole bunch of cracked wires.
Also, check all your injector/brain grounds at the large ground connector block under the plenum.
Lastly, plug wires and plugs. Get a ohm meter and measure each wire. Check the plug connectors. Check the plugs.
Andy
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