fuel pump acting whacky, car wont start any

[boostified]

Last week I finally was ready to take car for it's maiden voyage. (or so I thought) First of all, this car was a frame off resto. Motor is from my 86 t-type. Engine ran before just fine. Anyways, the car was running fine in the garage. Started, idled, and was in driveway ready to go. With no warning, just died. shut key off. turned key to on position. no fuel pump. towed back in garage. when I try to start car, fuel pump does not come on until I have cranked engine over for approx. 15 seconds. then it kicks on but still won't start. I have spark when cranking. have power to injectors, but have not checked while cranking yet. The only changes to wiring to engine is a gen 2 maf translator. With key on, should I see numbers for tps or o2 voltage. I don't know where to start. Any help is greatly appreciated

 

[mikestertwo]

Sounds like the fuel pump relay isn't working. The pump maybe coming on when the oil pressure gets high enough during cranking to close the oil pressure switch. I was thinking FP/INJ fuse but the pump shouldn't run at all even when you crank the engine. Are you sure you have power to the injectors?

 

[boostified]

I am positive I have power at the injectors. I didn't have a second person to check the pulse

 

[1quick6]

I'd also say to check your fp relay. When mine went bad, it would start and run for 15 seconds and then die. Probe the green wire and make sure it is energized when you turn the key to ON. It should energize for a few seconds to prime the system.

 

[boostified]

when I initially turn the key on, no power. after cranking for 15 seconds, I get power to the pump. possibly ecm trouble?

 

[mikestertwo]

when I initially turn the key on, no power. after cranking for 15 seconds, I get power to the pump. possibly ecm trouble?

The more I think about it, it could be an ECM problem. What kind of scan tool do you have? Are you showing any readings when the key is turned on? TPS, engine temp, MAF? Does your check engine light come on when you turn the key on?

 

[TurboBuRick]

Don't keep cranking it if it does not want to start. Thats a hell of a strain on the starter and battery. 5 sec intervals are more than enough.

Check the fuel relay for power. The green/black is the signal wire from the ecm. A 12v test light will work.

 

[Thumper]

check the end connctor pins on the ecm, on the longer plug and to the outside of the case, it controls the fuel pump, seen them bent and even broke off, don't know why, they even corrode and break off. Just a thought.

Thanks
Bill

 

[boostified]

my gen 2 maf translator has a system monitor function. with the key on, I get no tps voltage or o2 volts. I dont remember what the maf reading was. I am out of town working till tomorrow night. will check when home. Fuel pump comes on when oil pressure builds, but still wont start

 

[TurboBuRick]

Sounds like some possible wire issues with the gen2. Who did the install? How were the connections made? Or maybe the ecm is fried.

 

[boostified]

I installed the translator. I used the supplied tap connectors. I doubt that is it, just because the car was running great, then all of a sudden, died.

 

[Chuck Leeper]

How long did the car sit when the resto was done?
Bad fuel/junk in the tank, and you pulled it into the pump?

 

[RmvBfrFlght]

...the car was running great, then all of a sudden, died.

Check the SES/CEL light. It should light up at key-on,engine-off (and blink off for an instant). If not I suspect that the ECM battery or ignition feed is lost. Could also be the ECM grounds on the engine.

The ECM battery feed is from the battery via the orange wire with the fusible link.

My reasoning is as follows: cranking the engine builds oil pressure which turns on the fuel pump. This is correct & OK. However, the engine still won't run.

The ECM never turns on the fuel pump. Even the 2-second on time at key-on. And, the engine won't run even though the fuel pump turns on with oil pressure.

Even in limp mode (remove the PROM) the ECM will run the fuel pump when properly working.

So either the ECM isn't getting +12 volts or it doesn't have the grounds connected on the engine.

RemoveBeforeFlight

 

[boostified]

The car was apart for two years. But the tank was replaced, and the pump was wrapped up in a box the whole time. It has all new lines, and a new aeromotive 100 micron filter installed at the stock location. I highly doubt contamination is the problem. The ecm is getting power, or else my maf translator would have no power. The check engine light does come on for the two seconds when the fuel system should be priming. The only thing I suspect with the ecm would be the wire taps going to the translator. At least I have all winter to figure it out. lol.

 

[fallacy440]

same problem

hey, not to hijack you or anything, but my car did the EXACT same thing and i've been chasing my tail for months. if you find anything can you let me know and i'll do the same? is your check engine light staying on or shutting off after a few seconds? mine comes on then shuts off. are you getting any trouble codes? i'm not getting anything. jsut wanted to compare specifics to see if we could be having teh same problem.

 

[fallacy440]

May have found our problem...

hey, i was checking out my ecu yesterday because someone told me it might be bad and when i pulled the bigger plug out of it, the positive pin to the battery was broken off and stuck in the wiring harness. in reading up on the problem, it seems it's fairly common because of corrosion due to the computer placement in the car. they also said that they're known for being bent upon reinstallation causing a similar problem. i can't test mine until i get a new ecu so i won't know for sure, but getting no power to the ecu's sure to make it not start. just somthing to check.

 

[boostified]

I am going to check that tonight. If I have no luck, I have a buddy who does diagnostic service for a living. I am sure he can find the problem. I will keep you posted.

 

[fallacy440]

ok, yeah. keep me posted. i'm tracking down a new ecu and should have one mid to late this week so i'll be able to find out if it's 'the' problem or 'part of the' problem. hahaha! i'll let you know when i have results.

 

[87GNSteve]

Before you go crazy if you have a "good" Walbro F169 pump from 2 years ago it might not be so good after all.

 

[dan lephart]

fuelish problem

Sounds exactly like a problem I had after replacing a stock fuel pump. The brand new, fresh in from the supplier via UPS Walbro fuel pump initially started the GN, died then would not run the car. Heard it prime every time but would not start. Came back a day later and it tried to start and died. Re-installed and checked new hot wire kit. I diagnosed a faulty fuel pump that was breaking down under load. Of course the vendor said "we never have trouble with those." Got new pump from them, did third re-install, now with a new-new Walbro pump = worked perfectly! Old new pump ran fine outside the fuel tank. However, in the tank trying to push fuel it gave up!
Even a brand new fuel pump can be bad...