94CutlassSLCoupe Posted May 30, 2006 Report Share Posted May 30, 2006 Ok, so i've been working on the new '90 Quad 4... So far I have: 1) used the ignition system and computer from the other car 2) changed the spark plugs 3) tried the TPS from the other car 4) Removed timing cover and checked camshaft timing 5) checked fuel filter (it was new) 6) checked compression (even 140 in each cylinder as i suspect i either didn't turn it over enough to get a higher reading or my shit compression tester can't hold more than that) The car still runs, but when i take out the spark plugs, 1&4 had carbon on them and 2&3 looked just like i took them out of the box. The car just won't rev up and doesn't idle for shit (runs really rough) I did a resistance check on the injectors and I got 2.5 or so ohms on all of them, which is the same as one injector i tested quick while i was at the junkyard on another quad 4. It seems to have a decent amount of fuel pressure at the rail because it sprays pretty good if you turn the key on and then off quickly and check it. HELP!!! I gotta go back to MI tomorrow afternoon and i want to at least get this car to run! Quote Link to comment Share on other sites More sharing options...
94CutlassSLCoupe Posted May 30, 2006 Author Report Share Posted May 30, 2006 oh yeah and No trouble codes Quote Link to comment Share on other sites More sharing options...
mihela816 Posted May 30, 2006 Report Share Posted May 30, 2006 An Injector balance test is in order. That will point out problems with injector flow that can't be diagnosed with a simple resistance check. Quote Link to comment Share on other sites More sharing options...
slick Posted May 30, 2006 Report Share Posted May 30, 2006 You probably will not find any answers on here. I would visit the Quad 4 forum. That would be your best bet. Quote Link to comment Share on other sites More sharing options...
94CutlassSLCoupe Posted May 30, 2006 Author Report Share Posted May 30, 2006 already have Quote Link to comment Share on other sites More sharing options...
slick Posted May 30, 2006 Report Share Posted May 30, 2006 already have No luck? Do you have a scanner or access to a scanner? You may be able to pull engine data from it. Quote Link to comment Share on other sites More sharing options...
Slade901 Posted June 1, 2006 Report Share Posted June 1, 2006 Most Quad 4 engines I've seen when you have this problem is usually related to the Ignition Coil Housing Cover around $60 failing. Next possible problem is with the ignition coils itself. 3rd would be the ICM (Ignition Control Module). The way I test most Quad engine is to use a spare spark plug wires since this engine uses a DIS (Direct Ignition System). I then use the spark tester and pinpoint if I have a sparks. Again, it's mostly the Ignition Coil Housing Cover is the problem. Quote Link to comment Share on other sites More sharing options...
94CutlassSLCoupe Posted June 1, 2006 Author Report Share Posted June 1, 2006 Most Quad 4 engines I've seen when you have this problem is usually related to the Ignition Coil Housing Cover around $60 failing. Next possible problem is with the ignition coils itself. 3rd would be the ICM (Ignition Control Module). The way I test most Quad engine is to use a spare spark plug wires since this engine uses a DIS (Direct Ignition System). I then use the spark tester and pinpoint if I have a sparks. Again, it's mostly the Ignition Coil Housing Cover is the problem. I used the ENTIRE IDI cover (anything that's on that size of the engine harness connector), computer, etc from our other car which is mechanically identical and it didn't help. The other car runs perfect, in fact, my dad drove her to Philadelphia on tuesday! haha Quote Link to comment Share on other sites More sharing options...
Canada Posted June 4, 2006 Report Share Posted June 4, 2006 You need to check actual pressure with a gauge.....even 10 psi will come out of the valve at a good clip. Quote Link to comment Share on other sites More sharing options...
turby Posted June 4, 2006 Report Share Posted June 4, 2006 Swap the computers and see what that does. A guy at work had the exact symptoms you have and it was the computer. Quote Link to comment Share on other sites More sharing options...
94CutlassSLCoupe Posted June 4, 2006 Author Report Share Posted June 4, 2006 Swap the computers and see what that does. A guy at work had the exact symptoms you have and it was the computer. I did already...i'll try the pressure gage when i get home in two weeks Quote Link to comment Share on other sites More sharing options...
turby Posted June 4, 2006 Report Share Posted June 4, 2006 Swap the computers and see what that does. A guy at work had the exact symptoms you have and it was the computer. I did already...i'll try the pressure gage when i get home in two weeks Sorry, I missed that in your original post. Quote Link to comment Share on other sites More sharing options...
94CutlassSLCoupe Posted June 20, 2006 Author Report Share Posted June 20, 2006 ok, came home, checked the pressure...a good steady 41psi with the key on and it goes down when the engine is idling...i'm lost on this thing!!! arrgh Quote Link to comment Share on other sites More sharing options...
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