Team Integra Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
For some time now, basically when I first got my 1994 hatchback with a 96 LS swap motor in it.
Fixed all odds and ends, got her reliable and roadworthy, but still to this day I’m chasing down a few issues and could use some extra brains to help me resolve this.

Problem: Slight misfire at idle and when driving, nothing major, all cylinders have spark, fuel and compresson (although I have not yet done a check). Also, it’s been running extremely rich which I believe relates to this issue.

Stuff done: Headgasket, Valve seals & valve job (Cleaned, replaced some, re lapped, etc.) Walbro 255 fuel pump, AEM Fuel rail and regulator, 6an fuel line, msd coil and cap setup, adjustable cam gears, and most other available bolt-ons.

My engine if I’m correct, should run around 47ish psi fuel pressure at idle. When I set my pressure at that, I can tell the car is struggling for fuel. I am curRently running it a 52-55psi and it seems to like that more, but it seems way too high for idle pressure. And I feel like whatever my issue is here, that high pressure might influence how my car is running now.
Any input or advice to where I should look next would be greatly appreciated. I’ve gone through almost everything I can think of and I’m starting to get really fustrated chasing this down.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #3
Potential misfire culprits:


1. Distributor (igniter, rotor, cap, coil)
2. Spark plugs
3. Spark plug wires
4. Plugged injector
5. Clogged fuel filter
6. Faulty fuel pump
7. Wiring (fuel pump, injectors, distributor etc.)
8. Timing off


I may be missing few things.
At this point I’ve gone over each and every one of those issues minus saying screw it and either buying 4 new injectors, but I listened to each of them with a stethoscope and they all seem to open and close fine.
As far as timing, I have it set right in the sweet spot where it should be. However.. after changing the belt twice (first time I didn’t realize the genius bought a gsr water pump for my ls) and even still, my distributor is clocked to the advanced position quite a bit just to get it into time. I don’t know if this gives you any other ideas... but I appreciate any and all help.
-B
 

·
Registered
Joined
·
6 Posts
Discussion Starter #5
I assume all the valves were adjusted as well?
You bet. Checked a week after to make sure they didn’t loosen or tighten any too. I’m beginning to lean towards a possible unhappy injector, or worst case scenario I have a bad head, because I seem to be finding moisture buildup under my oil fill cap, however none on the dipstick. I have a catch-can setup with a filter and I do have a lot of moisture that gets into my engine bay so that might be the cause of that.
 

·
Registered
Joined
·
3 Posts
If you have a misfire at idle only, most of the time their valve problems, leaking/burnt. If not then I would double check mechanical timing and if that checks out ok, check make sure you have correct ecu, you didn’t mention having it tuned or with LS computer. Keep in mind a slightly burn exhaust valve will not show in a compression only in a leak down.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #8
If you have a misfire at idle only, most of the time their valve problems, leaking/burnt. If not then I would double check mechanical timing and if that checks out ok, check make sure you have correct ecu, you didn’t mention having it tuned or with LS computer. Keep in mind a slightly burn exhaust valve will not show in a compression only in a leak down.
After doing my last headgasket job I took the time to replace any concerning valves. Relapped and cleaned them all to brand new quality so I don’t think valves are an issue. Running a stock p75 manual ecu. Timing is always on point however my distributor is clocked advanced quite a bit to get within the 16 +/-2 timing needed.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #9
Check your compression, make sure there is no vacuum leak and verify that the grounds are clean and tight.
As soon as I get some clear skies I’ll hunt for any missed vacuume leaks but I’ve almost tossed that possibility out of the window because I do that often. And as far as grounds... well They’re all 2/0g wire lol
 

·
Registered
Joined
·
3 Posts
Well if your certain of no vacuum leaks a MAP will be my next check. Possibly even a oxygen sensor. Also I think a 255 pump with upgraded fuel lines and all is an over kill for a all motor LS.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #11
Well if your certain of no vacuum leaks a MAP will be my next check. Possibly even a oxygen sensor. Also I think a 255 pump with upgraded fuel lines and all is an over kill for a all motor LS.
I would agree, but with everything else I have installed on my car I’m able to dial it in to where the extra fuel IS being burned and properly. Still running essentially stock fuel pressure and I have extremely strong spark, will be installing a gifted 6AL to help with that too very soon. Oxygen sensor was bought new to match the ecu I’m using, but the more and more I think about it, it’s quite possible that it’s just simply needing to be tuned at this point. I’m pushing the stock tune with the motor setup at its max essentially.
 
1 - 11 of 11 Posts
About this Discussion
10 Replies
3 Participants
RetiredHippie
Team Integra Forums
The Team Integra community is a forum dedicated to Acura Integra enthusiasts to discuss engine building, suspension, repair, detailing and anything else Integra related.
Full Forum Listing
Top