When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
If you measured temps, why didnt you measure the runners??
Good idea. I was just trying to confirm that my different AFR's might be real. I wanted to support the difference somehow.
BTW I swapped the lean (AFR = 17.5) WB over to the other side and it read 12.5. That is what the other WB read when I run open loop, since the swapped arrangement gives up the SIM signal I was using to run my ECU before.
I will go back to original WB setup and measure individual runners temps.
Thanks,
Dave
OK, I'm not getting a clear shot to the runners for temp reading. I don't have a lift and I'm working on jack stands. I'm sure it could be done, but I thought I'd look from the top at the plugs. I am assuming (bad word) that I will want to send in all the injectors for cleaning.
I'll look tomorrow at getting runner temps, maybe.
Anything else to look for?
Thanks again,
Dave
Go disconnect & reconnect the spark plug cables one by one (on the lean side) while it's idling. I usually blip the throttle between each one so idle settles back down properly.
Pay attention how the idle drops and recovers (or engine dies) with each disconnect. The "bad" hole won't be as drastic of a change, if the injector is totally dead nothing will happen and BINGO you know which cylinder is the culprit.
If you are worried about getting zapped, then you need new cables.
Go disconnect & reconnect the spark plug cables one by one (on the lean side) while it's idling. I usually blip the throttle between each one so idle settles back down properly.
Pay attention how the idle drops and recovers (or engine dies) with each disconnect. The "bad" hole won't be as drastic of a change, if the injector is totally dead nothing will happen and BINGO you know which cylinder is the culprit.
If you are worried about getting zapped, then you need new cables.
Thanks, Hacker.
I disconnected each plug on the lean side. There was a slight drop or stumble with each one, but one, #2, was less of a drop than the rest. I do hear clicking on all.
Does that make you think bad injector(s)?
Thanks again,
Dave
Pull that plug, compare it to the others.
I've had a bad injector still "click" but something inside was jammed or broken so no fuel was coming out. These stock injectors? Have any spares lying around?
New thought.......
Is your car still using both fuel pressure regulators? Isn't there a test in the WSM to determine if one is bad which can cause a bank to be rich / lean compared to the other?
It's been so long since dealing with a stock L-jet car with fuel issues, this slipped my mind. I changed mine to a single FPR a long time ago.
There is a test in WSM where you clamp return line for each fuel pressure regulator and look for a pressure rise > 0.05 bar. If so, the opposite regulator is bad. I will try this tomorrow.
I was thinking the same thing, glad you mentioned it.
Thanks,
Dave
Last edited by j.kenzie@sbcglobal.net; 06-02-2017 at 09:21 AM.
Hello again.
Well I installed my fuel pressure gauge, and did the fuel pressure regulator tests in the WSM.
With engine running I get 36PSI and this does not change by clamping either FPR return line.
That's a little high; it should be 30 PSI.
Also a new problem:
I can no longer jumper my fuel pump at the relay. It worked the first time this morning when I checked for leaks after attaching the pressure gauge. Now when I try to jumper it, my fuel pressure immediately goes to zero, and all I hear are tiny buzz and crackle sounds at the fuel pump. In spite of that, the car starts and runs fine.
So:
Fuel pressure a little high, but regulators seem OK.
Can't jumper fuel pump, but car runs fine. ( 1 hour later Powered FP directly, and it runs. Now it jumpers and runs too.)
AFR on PS cylinders is 17.5, when DS cylinders' AFR' is 14.5
Sounds like:
bad injector(s) and,
marginal fuel pump and,
Fuel pressure regulators slightly out of spec? All probably original to car.
Thinking of servicing injectors, and replacing FP and FPR's (and damper, and fuel filter while lines open). Anything more (or less)?
Thanks,
Dave
Last edited by j.kenzie@sbcglobal.net; 06-02-2017 at 11:59 AM.
Reason: retested FP
Was: Dave, There's only one FPR. The other two are pulse dampers. On each those dampers, the vacuum connection is only there to safely route fuel that leaks through the diaphragm back into the engine intake. There's no "return line" to pinch, as they sit on the fuel rail with rail pressure underneath.
The regulator has the return line that routes to the top of the tank via the fuel cooler mounted on teh firewall. Pinching tha return line will give you full pump discharge pressure on your gauge.
I wish you were closer, I would bring over the box of L-Jet injectors which worked fine when I removed them for 42lb'ers. I'll be in Chicago next weekend!!!
If it's worth the cost of shipping to you and the time to install to test, I can get them packaged up.
Originally Posted by dr bob
Dave, There's only one FPR.
80-84 US L-Jet have a regulator on the back of each rail #28. The one up front is a dampener. The test in the WSM involves pinging off hose #8
Sorry, Dr. Bob. On the L-jet it is the opposite, for some reason. Two FPR's and one damper. The two FPR test is from the WSM. Based on that test, I did not find any lateralizing fault, but my pressures are just slightly out of spec.
I really think I have one or more bad injectors, causing my 4 rich/4 lean state.
Thanks again, and I always appreciate your advice,
Dave
Thanks, Eric. Your offer is very generous and tempting. If I'm going to pull all my injectors, I might as well have them cleaned and tested. I really do appreciate the offer. Are you thinking they are the problem, too?Thanks,
Dave
Thanks, Eric. Your offer is very generous and tempting. If I'm going to pull all my injectors, I might as well have them cleaned and tested. I really do appreciate the offer. Are you thinking they are the problem, too?Thanks,
Dave
If it were me I would swap out just the one which seemed like the worse cylinder above when you pulled the plug wires. That's easy for me to say having a box of injectors at my disposal though.
Did you pull the plugs? They all look the same?
As I said above, seems awfully similar to my Scirocco idling at 17:1 or worse with one bad injector as you measuring only one bank.
BUT.....as your car is supercharged, the first thing I did before strapping on the blower to my 81 was having all my injectors cleaned & tested. If you've never done this & they are original...... if it were me I'd send all 8 out even if that wasn't the issue.
My curiosity would want to pinpoint the exact problem by swapping in known good injectors. But I've wasted a lot of time over the years chasing answers when just fixing the problem would have been much faster (like just getting all the injectors serviced).
Keep in mind, L-Jet is a low impedance driver. This means you can safely run high impedance injectors (cheaper / easier to find) and Greg sells adapters to use the style from an 85+ car in an L-jet:
Thanks, again, Eric. I think I should have had the injectors cleaned before I put in the SC. This will be my chance to change the seals also. If I get a lot of variation on the injector pretest, I should have a pretty good idea.
Hopefully with injectors serviced I'll have uniform mixtures.
Thanks,
Dave
Last edited by j.kenzie@sbcglobal.net; 06-03-2017 at 09:03 AM.
06-01-2017, 09:14 PM
