stuart69427

Ok lets start from the begining....

For a few months the car has been acting funny but its been off and on (like its acts up for a few days and then runs beatifully for like two weeks then acts up again for a few days, and so on...)

The last time it was acting up, i followed tom very detailed checklist to find out my connections at the fuel pump relay were shorting each other out, well i fixed that.

I open the hood and I can hear the relay kicking in, but occanionally (like last night, and not this morning) i will hear the relay but not the "humm" from the fuel pump.

this is a really strange situation cuase for like the lst three weeks or so the car has been running better than ever! Perfect idle, stating in less than a second, better pickup, great gas mileage, i mean its just been running great!

Well yesterday i went to border to pick up a body repair book and as i plled out of the parking lot it stalled. And i tryed to restart it, and it will start, run up to 1000 rpm and then completly die.

I through it in nuetral and let it slowly rull down the hill in the parking lot and had fun without power steering and no power brakes to get it into a open parking space at the bottom of the hill!

I let it sit while i cussed about forgeting my cell phone ( a lot that AAA is going to do me there!) I poked my nose around the engine bay and used that handy dandy multimeter Wayne helped my find! alt and bett is good!

I disconnected the IAC and was able to at least drive it home. Of couse driving it with the IAC disconnected was fun, car simply just stall even when i was running 45 down the parkway, erratic as can be! Worst knocking and pinging i ever did see! So much "jerking" youd swear i was at a rock show...

I got it home and was in the mood, ok "please be something other than fuel pump" cuase i replaces mine in december and this time i know tha i'll have to do it myself, cuase labor was $300 bucks and i can't afford that right now...

Ok the problems that could cuase this in simple terms can be : IGNITION, VACUUM, and FUEL...

Vacuum holds a steady 16psi (16psi - 20 psi is normal)

Ignition all checks out except for these two questions:

1.) Why is my spark purple ???? (nobody has ever answered that)
2.) How do I check to see if my Ignition modular is bad ???? (its one of things that could be stting the code 42, but thats most likely cuased by the disconnected IAC)

That leaves a fuel problem...

My fuel Pump Relay is good, i do know that. I ran out of time to disconnect the fuel filter and see how the flow is doing. On my way home i will buy a new fuel filter (old one was put in about a year ago). I will see how that is before i go out and purchase a fuel pressure guage (might see if neighbor has one, big miata enthusiat, guy driving a miata, yuck...)

Just to inform you guys of my work i am cut out for...

And one more thing, Wayne, i'll only resort to taking it the the shop if i have too!!!!

stuart69427

forgot something, when i had my fuel pump replaced, the guy said my fuel sending unit was clogged, but i told that to you guys and you said thats inpossible, just to reclarify, is this correct ???

The mechanic wanted $500 bucks for that sending unit, what does one cost???

TomP

Yeah, sending unit can't be clogged- the pump acts as the pickup for fuel. Only two thing the sending unit's good for? Measuring the fuel level, and holding the pump in the tank. That's why the sending unit is so expensive, it comes with the whole float and bracket assembly, not "just" a fuel level sender.

Could the timing be way off? Doesn't make sense that you could drive home with the IAC disconnected. Could the MAF be dead? How does the car run with the MAF disconnected (and the wire harness tied up out of the way of the fanbelt)? How's the inside of the distributor cap and the rotor, is the rotor melted?

stuart69427

with the IAC disconneted the car holds a steady 11 degree timing scale.

Rotor and cap, and plugs too, were all cleaned tuesday with the brass tip on my Dremel... All intact...

I ran tests on most ignition stuff, all plug wires check on resistance, coil checks out, all six wires were attached to the spark tester, and all six were PURPLE...

Pick up coil is all good!

I'll check the MAF, the book to the Sunpro Digital Multimeter we have shows how to do that with the multimeter (which is why i don't understand why you bought a MAF sensor checker )

WaynesRS

your purple spark is normal . my spark looks blue but you might think its purple , but theres a fine line between purple and blue sometimes .

MDv6man

Three things

1. When it acted up, did you put a fuel pressure gauge on it?

2. To drive it home and check the timing , you mentioned disconnecting the IAC? Did you also disconnect the EST or did you really mean EST rather than IAC?

3. Did you buy a new relay? sometimes these things work intermittently. My 85 had one that was going bad. I would start the car up and it would kick out a code 54. Turn car off and re start and code went away. There was no change in the drivability -- just an SES light. One day, I had to stop quick and the relay took a dump. Car wouldn't start. I switched connections with the blower relay next to it to get home. Maybe you should swap the two relays and see how the car behaves.

stuart69427

I changed the fuel filter and it now runs and it runs fine if i might say so. But i t still idles iratic, but not as iratic. It can go under 500 rpm without stalling now! Man that filter was dirty. I replaced it a couple weeks after I got the car august 3rd last year (tommorows our 1st anniversary hehehehe) Amazing the how dirty that got, but anywho...

To answer your questions:

1.) I dont have a fuel guage (nor could i afford one right now, might see if i can borrow one) but i did the the why "Haynes" said and it pumped out about a cup and a half in fifteen seconds (but that was right out of the new filter, not the fuel rail) and the book said as long as it pumps a 1/2 pint (a cup) in fifteen seconds it should be good. Will check the fuel rail later today, it my lunch break right now....

2.) I meant EST (sorry Tom) i hate when i type something and mean something else.... And my timing holds a steady 11 degrees, but i'll recheck that now i got it running again... hey, it never hurts....

3.) I don't think its the realy, cuase i can hear the relay kick in, but sometimes i don't hear the "humm"... But I quess it will never hurt to replace the relay ( I still need to replace the Oil Pressure Safety Switch thing in case my relay does give out, quess that would help, huh ??? )

TomP

No sht! I never read the book on the multimeter; figured a meter was a meter. And I bought the sensor tester 2 years or so before sunpro had the meter up on their website. (And who can argue with more tools? hehe)

Oh so you unhooked the EST, and that's how you got home? Weird. Oh hay, wait a minute... brain is thinking... I wonder if it's the spark module. Try running through this chart I started typing up for a friend's friend, and I never finished, because I realized the kid would probably have a hard time reading it, let alone running the chart! (In other words, why waste my time! I'll have to finish typing it up for our club here.)

https://www.thirdgen.org/techbb2/sho...hreadid=103866

Classic "dead module" case is this: Engine runs well when cold, suddenly gets crappy when hot. It'll stall, and not restart until the module cools. Were you in the bookstore for long (hours)? Or was it quick? I wonder if the module soaked up the heat, and took a crap... and as you played with things, the module cooled down...

Does ebay have any fuel pressure gauges, I wonder?

LT1guy

iTrader: (1)

Redraif's car did something similar...we checked the relay, all the connnections, and finally traced it back to the ECM. IT wasn't telling the fuel pump to kick on like it should. The car would start, eventually, but sometimes it took forever and sometimes it fired right up. There is a page long diagnostic procedure in the factory manual (far better than the Haynes, get one if you can) that helped us track it down. If you can't find the problem, email me and I'll send you a copy of the test.

stuart69427

Ahh, I hope it ain't that, but i still have the old AC Delco one from before the distributor rebuild, i'll try that. This only happens in this crappy hot weather we are having, its like an index of 105 out there... Its only having acting problems when it gets warmed up, but my engine temps rarley exeed 160 even in these insane heat wavves were getting...

Going out to do more tests and try out the old modular...

only in bookstore maybe 30 minutes ???

ebay probabley has one, i'll check....

All, i replaced the relay, and had fun in Pepboys parkinglot afterwards, trying to get home...

TomP

LT1guy, you mean the code 54 chart? I typed it up a while ago, the last time I posted it is here: https://www.thirdgen.org/techbb2/sho...hreadid=116965 You said you ran through that already, though, right, Stuart? Maybe the ECM fried itself after you changed the relay?

Did you put the heat grease on the new module?

stuart69427

I quess i fried the Holley Modular, put the stock AC Delco one back in and she runs great (knock on wood) so i will only have that AC delco for now. I put tons of greese under there, but somehow, there was barely anything left when i pulled the Holley out

stuart69427

The ral test is just to wait till it gets hot tommorow.. then will see how well she is fixed...

LT1guy

iTrader: (1)

Thanks Tom, that would be the one...its been a LONG week (my reg job plus helping Shannon remove ground effects and install the 4th gen mirrors), with very little sleep, and I couldn't remember the code for anything!

stuart69427

so far, so good, waiting till tis afternoon to see how she runs in the heat!

Man i miss the smooth idle of the Holley Modular, My car runs good, but the Holley Modular is just an awsome idle... This 14 year old AC Delco just doesn't compare but hey, its running now, i'll get another Holley with my next paycheck and keep the aC Delco in case of another heat stroke I hope not...