PT Ray

I went to start my SE after work yesterday and it would not fire. Today I checked the leading and trailing ignition with a timing light, got positive readings on both. I don't feel it is fuel problem, both the pump and filter are less then two years old with about 20k miles on them. Been able to redline and never noticed any indications of fuel starvation. Won't eliminate it but will assume its fine for now. My next step is checking compression. I am going to get a conventional tester hopefully giving me a general idea. I am looking for some input on this. In less I missed something, if there is a bad apex seal two of the pulses will be significant lower than the third. If there is a bad side seal, one pulse will be significant lower.

There have been some issues leading up to this. First off, it is an original 22 year old engine but not original to the car so actual mileage is unknown. For the last three months, my gas mileage has been getting worse. The last few weeks, the car would idle around 200rpms and slowly make it to 700rpms. A couple times this past week I had some hard starts. It was turning but no indication it wanted to fire up, then finally it hooked up with a little erratic idle. Just figured it was time to replace plugs and wires, maybe this still applies.

One thing I do know, I have an extra engine sitting in the garage, thanks AWS140. Has 100k miles and was running before the car was retired due to an impact to the rear right quarter. I am banking on it just needing a complete rebuild kit and new rotor housings to give me a strong stock runner for the next 50k miles.

trochoid

iTrader: (6)

Have you ever had your injectors sent out for service? The declining fuel mileage may indicate injectors sticking open The hard starts would be a result of the fuel pressure bleeding off through the injectors, flooding the housings.

Rx-7Doctor

iTrader: (13)

First thing i recommend is to inspect the plugs and see if they are gas fouled.

PT Ray

trochoid, it does not seem to be a flooding issue but could be wrong. A co-worker with an 86 Vette was telling me he was having hard starts. I only know first gen 7s let alone Vettes but we went outside and he showed me. He had to turn it over for a couple seconds, wait a couple seconds, and then turn it over again before it would fire. It was a slow fire with the first runnings of exhaust rich in unburned fuel. I told him his injectors were bleeding. He had it serviced and sure enough. My case is when it did fire, it was solid with no strong exhaust.

I have flooded my sevens before. Pulled the plugs, bypassed the fuel pump and turned the engine over to purge the fuel. Put it back together and turned it over, nothing. I can pour a gallon of fuel down the intake and roll start it in a drive way everytime. This time it was a parking lot and not one indication it wanted to fire. One reason for thinking there is still a chance it is an ignition problem.

Rx-7Doctor

iTrader: (13)

The most common hard or no starts on a Se are the following.
1). Bad AFM. Meaning that when you trun the key to the on posistion the fuel pump comes on and is not supposed to until you start to crank.
2). Leaking injectors or stuck injector
3) Bad coolant temp sensor
The only ignition related no start i have come across that is rare is that the dist rotor grounds thru the Dist and causes a crossfire situation.

trochoid

iTrader: (6)

Pull the dizzy cap and check the rotor and contacts in the cap. Otherwise, listen to doc, he knows the SEs inside out and I have only worked on one that rarely comes in the shop.

Fwiw, when in the start position the pump is energized, once the key is returned to the run position, the afm door keeps the pump circuit open. I still suspect the injectors though.

Put a timing light on each plug wire while cranking, that will show if there is spark or not. You can pull the engine fuse under the dash while doing this to disable pump.

Have you had the injectors serviced, and how many miles on the fuel filter, it may be time for a new one.

LongDuck

Well, you have spark, as stated above, you need to check the AFM to make sure it's operating the fuel pump correctly when air is coming in. This accomplished by either removing the Air Filter and pushing on the AFM door with the engine off (key in 'RUN'), and listen for pressure at the fuel rail, or better yet, grab the fuel pump shunt (green plug under the AFM area) and connect both lead together with a short length of wire with 2 spade connectors on each - this will bypass the AFM switch and allow the Fuel Pump to run even without the engine running.

If you hear fuel pressure at the rail, you have spark, and you don't have fouled plugs, then you must have a bad lead to the injection system.

Check the Fusible Links at the Driver's side strut tower, specifically the one marked 'ECU' and 'INJECTION' and test these for continuity. Better yet, replace with 'known-good' and then try again. The ECU gets it's signal from the trailing coil (black lead to "-" pole), and if this lead is broken somewhere, shorted out, or otherwise not sending a signal, then the ECU won't know when to fire the fuel injectors - resulting in crank but no start.

Have a look at that, and your plugs will tell you a lot more than I can in the space of a reply. HTH,

PT Ray

Here is a quick follow up:

Had the car towed home. Cranked the engine for a couple seconds, pulled a couple plugs with no trace of fuel to be found. Disconnected main fuel line and put it in an empty mmo bottle to catch any fuel. Shorted the fuel pump terminal, nothing. Went to the fuel pump and removed the sheilding to check for voltage, the pump kicked in. Then I realized my catch container is going to overflow, lost a little fuel before stopping the pump. Reconnected fuel line and powered pump back up. Went back under the car and pulled on the wires and shook the pump attempting to recreate the failure, no luck. Not sure if I should just replace the pump (lifetime warranty) or drive it until it fails again.

GavinJuice

i am confused as to how you shorted the fuel pump terminal and the pump didn't run, then you removed the shield and checked for voltage and the pump ran?? So you have voltage jumpered, do you have voltage when you Crank the engine AND when you prop the AFM flapper open?

How did you short the terminal first of all, did you jumper the fuel shunt like LD said in the engine bay?

PT Ray

I used a jumper to short the "fuel pump shortcircuit terminal" meaning the pump should be running with the ignition in the on position, mine was not. Either the the pump was not getting voltage or the pump itself was toast. I went under the car to unbolt the pump for better access to the wire terminals for a voltage check. In the process the damn thing kicked in. Unless I could recreate the failure, no way to tell what the issue was.

LongDuck

Pump stalled, or fuel pump wiring is bad somewhere along the way.

When the 'shunt' is in place by the AFM, anytime the key is 'ON', the pump is running. This is to check fuel injector pressure and leak testing.

If your fuel pump wasn't running until you got back there and 'whacked' it with something, it's an internal pump motor failure (stall). Just keep in mind that if it strands you again, whack the fuel pump housing and try again. Not much to fix; replace when able.

JIMMY54

iTrader: (2)

Inspect your cap and rotor very closely...

Then something you should know is, On a GSL-SE your injectors will not open if your ingnition system isn't working!! Took me a long time to figure this out!

Check the fuseable links and test them with a continuaty tester.
Check wiring around the coils, (I once had a wire unclip from my coil)
Check your Ignitors, Haynes manual shows you how.... very easy to do.

Sorry I have to run to work, or I'd fill a page!

PT Ray

Didn't whack it, just unbolted to reach the terms. better and it started pumping. Thought it was a bad connection, pulled, bent and twisted the wires and it still kept going. Still have it on stands debating over replacing the pump. Think I will just go ahead replace it since it has a lifetime warranty.

trochoid

iTrader: (6)

Might be someting as simple as a bad ground/connection or pinched wire. Look closely.

blazer1313

^I agree...check fuses and fusible links too just in case. If you search you will find if you connect a regular LED to a connector by the ECU you can see if there are any Trouble Codes....

hmm should've read farther...you already found the problem..

Kentetsu

I'll go with the bad fuel pump theory. My Audi did that to me once and left the wife stranded. I drove over a hundred miles, saw that I had spark but no fuel, banged on the gas tank a few times (internal fuel pump) and she started right up. Once it was going, it got us home. But after I shut it off again she was down for the count. As long as your pump has a lifetime warranty, you might as well take advantage of it...

bliffle

Well it finally happened with my SE: cranks good but no start. Gives a little skip once in awhile like it wants to start. No gas smell. The last few days it's been idling a little high, 2000rpm, but running good. I'll try it again in the morning, maybe with a shot of starting fluid or gas to eliminate fuel problems.

Lately, per advice here, I've been giving the exhilerator pedal one stroke before starting, but I didn't this time, just left it alone.

I'm searching, I'm searching.

bliffle

Started right up this morning, even with the battery low from yesterdays exertions. I gave the accelerator pedal one pump first and it started immediately. Exuded great clouds of smoke from the excess fuel. Neighbors gave me a fishy look.

OK, so that's it: you gotta give the pedal one pump before turning the key on an SE. Just like another old SE owner has said here. Sometimes it starts without the pump, but it's not reliable. I suppose the pump initiatilizes some condition properly.