TX Speed Demon
Member
Could use a few suggestions from anyone who has thrown this combination of codes before.
P0300 - Random/Multiple Misfire
P0090 - Fuel Pressure Regulator 1 Control Circuit
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Description of problem: Started with an erratic idle and an occasional hard time starting up. Occasionally the RPMs would bounce between 1K-2.5K right after start up before settling down at the normal range. This happened 2-3 times over the course of a month. Then it would occasionally have trouble on acceleration - seemed like it was bogging down (maybe having a hard time burning fuel). When this happened the car would want to stall, rpms drop all the way down as if I had a huge vacuum leak. This happened twice over the course of two weeks. No CEL codes were present at this time.
At this point I made these changes on the car:
New exhaust manifold gasket - this eliminated most of a leak I had there. Still sounds like a tiny one is there upon start up but closes itself within 30 seconds of warming up
Replace radiator - was seeing minor leakage/seepage at the top and figured I'd replace it since I had to pull it out to get the exhaust manifold off
Replaced spark plugs - gapped to about .30
Replaced Fuel Pressure Regulator (thought this was the problem)
Car ran fine for about 2 weeks. Then the hesitation came back. On the first occurrence the CEL light started blinking, the car ran horribly (like it's on only a few cylinders) and would stall out any time I wasn't giving it gas. I limped it 1/2 mile home never going over 2K RPMs, checked the codes and those were the two that came up (P0300 & P0090).
I'm thinking it's the coil packs needing to be replaced (125K miles on them) but wanted some second opinions on if this was the likely culprit or if a bad fuel pump (or something else) was more likely before I bought any other parts.
One other thing to mention - the problem started shortly after I did an oil change and Sea Foam treatment in the vacuum line (is it possible this caused a problem with my injectors causing these codes?) I've done the Sea Foam thing multiple times before this with only positive results so don't think it's the reason for the problem, but thought it worth mentioning.
Any thoughts/opinions are appreciated.
P0300 - Random/Multiple Misfire
P0090 - Fuel Pressure Regulator 1 Control Circuit
---
Description of problem: Started with an erratic idle and an occasional hard time starting up. Occasionally the RPMs would bounce between 1K-2.5K right after start up before settling down at the normal range. This happened 2-3 times over the course of a month. Then it would occasionally have trouble on acceleration - seemed like it was bogging down (maybe having a hard time burning fuel). When this happened the car would want to stall, rpms drop all the way down as if I had a huge vacuum leak. This happened twice over the course of two weeks. No CEL codes were present at this time.
At this point I made these changes on the car:
New exhaust manifold gasket - this eliminated most of a leak I had there. Still sounds like a tiny one is there upon start up but closes itself within 30 seconds of warming up
Replace radiator - was seeing minor leakage/seepage at the top and figured I'd replace it since I had to pull it out to get the exhaust manifold off
Replaced spark plugs - gapped to about .30
Replaced Fuel Pressure Regulator (thought this was the problem)
Car ran fine for about 2 weeks. Then the hesitation came back. On the first occurrence the CEL light started blinking, the car ran horribly (like it's on only a few cylinders) and would stall out any time I wasn't giving it gas. I limped it 1/2 mile home never going over 2K RPMs, checked the codes and those were the two that came up (P0300 & P0090).
I'm thinking it's the coil packs needing to be replaced (125K miles on them) but wanted some second opinions on if this was the likely culprit or if a bad fuel pump (or something else) was more likely before I bought any other parts.
One other thing to mention - the problem started shortly after I did an oil change and Sea Foam treatment in the vacuum line (is it possible this caused a problem with my injectors causing these codes?) I've done the Sea Foam thing multiple times before this with only positive results so don't think it's the reason for the problem, but thought it worth mentioning.
Any thoughts/opinions are appreciated.
Had planned to call him this weekend to see if he has an extra set of injectors i can use to test to see if that is the problem. Thanks for the heads up.
