Fred & Veda's boy

Well after several days waiting in the shop they tracked down a ecm with a open ground and several wires in the area that were melted enough to give concern. fuel pump was bad in that when i did trouble shoot and put 12 volts to it it turned over but no pressure. Then even with that resolved the other issue of low spark or poor spark depending on which tech I was speaking with. I remember having trouble in the past with the dash lights malfunctioning and replacing the whole dash assembly and even then blowing the 7.5 fuse for same but no problem for 9 months after that. I have a gut feeling that after 20 years the main harness is redy for replacement. But that would require selling one of my grandchildren !

Well I'm still deep in it. The jumper across B+ to FP and I have 12 volts to the EFI with and without the jumper. I also have 12 volts to the relay marker fuel pump relay. I see on the diagram fusible link and is said to be close to the battery. I don't seem to find it . I was wondering if they show like the ford links that wrinkle up noticeably when blown? Where exactly is it located? I did mention that I put 12 volts to the pump and I could hear it running but i wouldn't start.

Randall I installed the jumper B+ fp. Igition on I get nothing . no start and no noticeable noise from the pump.

Randall Thanks so much . A quick bite and i'm off to the shop. Will contact you asap Tom

Randall I seem to have miss read small print .Your post read breakout connector. I saw check connector?

Thanks Randall, The fuel pump relay under the air pump cover on passenger side forward fender well has a 4 blade connector outside back pin has 12 volts on it and direct inboard pin has 5 volts on it . With in switch on, this is curious to me. On the above diagram the item marked "check connector"labeled in the engine compartment?

Sorry Bob , long day Correct now with " No Code and the second read out was unable to read at least that is was he said. I also made up a small jumper wire for him and he attempted to read the blinking light system as I just read though.So now I know exactly what he was doing. With the jumper wire is when he said he was unable to get any blinking light. With his code reader plugged in standard he said it read no code. That is the best I remember. I was wondering could I put 12 volts to the pump connection at the rear top of the back seat (now removed) to see if pump will run or if there is pressure already built up will it be held out or off? I don't know if i'm thinking correctly?

Thankyou, It does start with a shot in the intake and there is power to the fuel relay on the passenger side front under the cover marked airpump. I pulle the rear seat and checked for power at the two wires with the key on. no power. Remember this car gives a now code with one reader and Can't read with another. I don't know exactly what kind of reader however this same man read my neighbor's 92 toyota with success.

Ialso checked battery voltage and cranking voltage. 11 volts cranking I'm going to pull rear seat after I check for fuel pressure with the key on.

Bob Timing belt is good. We had it done with a starter R&R last year. Water pump as well, in as much as we were told to do the starter these items should be addressed because of the major undressing of the engine to do the stater.

opps typo on pervious post not marker, but- toyota marked fuel pump relay.

Thanks Bob. I have a Drs appt this am . But I'm going to check the belt before I go. The 94 is different than the 93 in some small ways. I have access to a 93 in storage from a friend. I have seen some post about the fuel relay being in the trunk and don't find anything on our 94 there on either side back there. I did find the marker fp relay under the air pump cover on passenger side forward . One person said to swap a/c relay with the ecm relay as they were the same. That did not seam to make sense to me . As I said ,I'm not up to speed on this unit yet. But I will null this out or die trying. :-)

Thankyou for your reply. no Joy is my slang for " it did not work." The trouble shooting I did was to First listen for the short pump charging sound that I always hear. And you are right it does not happen when it is a quick restart and the fuel system is up to pressure. The sudden blink of the dash lights and engine tach fall to zero seen as the lights were on .So I thought it must be electrical . Battery voltage after all the cranking was 12.6 static. I did not check while cranking. The engine cranks fast and strong. Then I pulled the spark plug wire and confirmed spark. Found the fuel pump relay under the air pump cover and replaced same . Still no result. At this point because I out of the loop for 5 years being bed ridden, I'm just part changing. I don't care for that. I also had a gentleman tech type come with a diagnostic reader and got no code and can't read code and used a jumper to try a older method of the blinking light readout like the older Gm & ford use to have. Still unable to get a code. With the battery connection being the problem would it drop out that fast with the motor running?

1994 Ls 400 I Love it. Driving away from home , 2 miles out and the dash blinked and engine quit. I tried to start and no joy . It turns over normal. I checked Battery voltage , spark and fuses , all good. I don't here the fuel pump charging when I turn the key on. I changed the fuel pump relay. Again No joy. I had a tech guy come to read code after 2 hrs and several different attempts to get it to read . It said no code or unable to read ? I get the felling that it must be electrical , Any help would be gratefully appreciated.