1979-1993 & 94 Conv [Subscribe to Daily Digest] |
![]() | [Main C900 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
'89 SPG strange running - Fuel Pump Question (longish) Posted by RS [Email] ![]() ![]() ![]() |
I suspect that the catch-drop-datch-drop running on my '89 SPG is a fuel volume or pressure problem. But I don't have a pressure gauge to measure it.
Is there a banjo fitting on the top of the fuel pump assembly that I can just unbolt or do I need to push the fuel line onto a bayonet fitting?
I'm going to swap fuel pumps with a known good one from my '88 900T parts car.
It runs perfectly at idle. When the gas pedal is pressed, the RPMs rise and it hits a point where it just dies and the RPMs drop back down. It does this cyclically as long as the gas pedal is pressed down. If the throttle opening is greater, the cycle time is longer. If the throttle opening is small, it doesn't die back as violently as it does with a large throttle opening. The tach shows a smooth transition between 1500 or 2000 RPM and idle, so it's not the hall effect sensor or the ignition module.
Here's what I've done to diagnose it so far.
Swapped in 3 known good 013 AMMs. No difference.
Ran it w/o an AMM. The CE light goes on, but no difference other than that.
Took off the plug on the TPS. No difference.
Took off the vacuum line to the FPR and plugged the vacuum nipple. No difference
Run without the O2 sensor. No difference
I'm also going to replace the fuel filter just in case that last major gas filling stirred up a lot of sediment in the tank and plugged up the filter.
posted by 172.164.182...
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
![]() |
![]() |
![]() |
![]() |
![]() |