Legoland951

Did you just reassemble the engine? Sometimes, it takes about 10 minutes of engine running for the lifter noise to go away.

roco16

Right, but the engine wont even run for more than a few seconds. That's why I'm trying to track down the fuel/ignition problem.

Gerald Allgire

Does the gas smell like vinegar? Bleed some off the injector rail, take it outside and light it with a match. Do this away from the house, in the yard or something. Gravel driveway works nice. BE CAREFUL! If it lights quickly it's good enough. Wouldn't hurt to put some dry gas in the tank just in case it collected moisture since July.

Do you have the rubber boot tightened up on the throttle body?

brad-cam

roco16, sounds crazy but it happened to me so...

Check that the AFM wire is connected properly, all clamps on intake plumbing after the AFM are tight and hoses are connected. Check spark plugs are tight, wires aren't arcing. I've started my car up after a repair and had it behave like yours, panic, and then find it to be something I forgot, like an intercooler pipe not reconnected.

You only had the cam tower off right ? Not the flywheel sensors ?

Gator_86_951

I second checking the AFM connection to the DME, the TPS, and the reference/speed sensors. Since You have fiddled with the injector harness you may have introduced the problem I had. I rebuilt the top have of my motor this summer and when we finally got it back together no start. Bummer. Turned out to be a short in the injector harness right where the injector plug was for cylinder #2 i think. Harvested a connector from the SAE-EFI harness and that was fixed. In fact, one of the symptoms was the car would run and then manipulating the harness a bit would get it to short and the motor would die.

Before that we checked everything. So, now I know everything else is in spec right :-). Including replacing a reference sensor which had a fussed up connector. The output wasn't nearly peak-to-peak as the manual said. So, we replaced it. New one had the same output. Meh.

roco16

The connections for the MAF & TPS were fine (which doesn't say if they are working or not). That was one of the first things I checked. The plugs are tight, but I am not sure that they are firing correctly. I am going to try pulling one plug at a time and turning the motor over with the starter (and fuel pump fuse pulled). That will eliminate spark from the equation. After that there are only two other possibilities : fuel and air. The fuel smells good (got it all over me when I replaced the injector seals) and the intake connections are normal.

Gator - I think that I might very well have a problem with the injector harness. The wires going to the injectors look and feel terrible, and the plugs seem pretty worn out. Are they easy to replace?

Gator_86_951

roco:
First thing to do is checking the wiring diagram and determine if any of the connectors are shorting. The connectors are standard bosch fuel injector connectors. I lucked out and my buddy still had the EFI harness from an SAE car built here at UF like 5 years ago. So we harvested one from that. I also lucked out in that we didn't need to look very hard to find the short.

P.S. - Comp. Eng Graduate student at florida. Had a bunch of friends that graduated from tech in fiji.

Legoland951

Diagnose whether its a compression, timing, fuel, or ignition problem. It has to be one of the 4 and once you can narrow it down, then you can figure out what is wrong or no one can really help you more than guessing. Get a compression tester for compression, a can of starting fluid for the fuel, screwdriver in the sparkplug wire for the ignition, and pulse of the spark for timing along with timing marks. Without finding out those 4 things, we will be guessing for months and wasting time.

roco16

Legoland951,

Thanks for the reply. Your advice is pertinent to the average inexperienced troubleshooter whose motor will not start. Unfortunately, it doesnt help me much because you might have missed what I previously posted:

Maybe I should clarify the purpose of me posting this thread. I'm not looking for general advice such as "Diagnose whether its a compression, timing, fuel, or ignition problem." This is good advice, but not what I need. Replies like what Gator_86_951 said:

are treasures within Rennlist. So, with that in mind, if any of you guys out there have experienced idle difficulty because of a faulty ________ , I would love to hear about it. Thanks again to those of you that read the thread and have given me either hope or relevant info.

-Robert

Gator_86_951

So, it runs now and doesn't idle well?

Legoland951

Sorry I didn't read all the info. Air/fuel can be checked with a can of starting fluid. If you still can't start it and keep it running with starting fluid, then its not your fuel system or your a/f mixture. Sometimes, the plastic part of the ignition switch or the speed/reference sensor can cause intermittent starting problems along with shorts in the injector harness (happened to my cousin's car and major pain to diagnose - caused by excessive pulling on the injector plug). If you can run it on starting fluid, then check for leaks/break in the vacuum lines under the intake manifold since they are easily broken and brittle with age. I am not sure how changing the pan gasket or the modifications you mentioned in your original post can cause the car not to run though.

roco16

Gator-
When I start the car, it runs for about 1-3 seconds quasi-normal, then drops to 300 car-shaking-rpm.

Lego-
No problemo. I just didn't want you (or others) to waste their time. I hadn't thought of trying to 'run' the car on starter fluid. How exactly do you do that? I've always heard that you spray a bit of starter fluid into the intake to get diesels and other hard starting cars to kick over a few initial times. Thing is, my car starts ok, then completely falls out of whack. It acts alot like when I tried to put regular GURU racing chips into my APE MAF equipped car: It starts ok, then shakes violently at 2-300 rpm because the fuel maps were programmed for a regular barndoor flowmeter's voltages, not that of my MAF.

As far as vacuum lines go, I've replaced all the vacuum lines with LR's kit, and updated the idle octopus months ago. It has been otherwise fine since then.

-Off topic-
Gator- Never knew any kids from Fiji. I almost went greek, but decided to focus on my co-op research job instead.

Lego- Is that bike a GSX-R 750 or 1000?

Gator_86_951

roco16:

Another thing this could be is over-enrightment. The DME/Ignition will do exactly that if the mixture becomes over-enriched. One of the ways I know of to cause this is if the temp sensor at the front of the motor on the block right before the head was disconnected. IE, the water jacket shown in my avatar top right corner. There are other things that can cause over-enrichment as well. Do you have access to a factory repair manual. It details a whole list of things to check for no start / bad running.

roco16

I'll check the manual tonight. So, you are saying that if the temp sensor is disconnected/malfunctioning, the a/f mix goes waaay rich???

Gator_86_951

Yes. I wish I had something better to do right now then check rennlist. But I refuse to do my computer architecture homework and I am tutoring the kids right now :-). Will make the a/f uber rich and the motor will die.