Hey guys.. new to the forum hopefully someone can help. I'm in an automotive tech program in school so I'm worthy but no where near an expert Haha. This is my first Volvo and usually I buy cheap cars. And fix them up to sell but this one I bought for Emmy wife and I because were expecting and I could useva four door car. I got it off of a Guy That claimed he ran it through a huge puddle and it died. I only got it for cheap jut I'm hoping to save it and not scrap it. The garage he took it to said it needed a new Ecu. I got a new one on eBay and was told it didn't need calibrated because of how old it was. Hooked it up. Changed the plugs wires oil air filter ignition coil district cap and got it to start.. for five seconds. Sprayed a little starting fluid in it and it'll start but only for a few seconds. Plugs are dry which means no fuel I'm assuming but every now and then it'll start up without starting fluid but only for a few seconds. Code I got on the little code scanner by the drivers side shock said 1-2-1 on port two. No other codes on any ports. I looked it up and it said mass air meter. Bought a new one and the code went away but still same situation. I popped the fuel relay out and every solder and connection looked good. No fuses blown. Little help? Also on a side note the orange up arrow on the cluster is on with the accessory and flashes when I try to crank it. Everything was working fine he said before his water incident. Any input will be a huge help. Like I said I like learning on new cars and I'm hoping this car isn't headed for a scrap yard because its gorgeous. Thanks guys.

 

I think the first thing I'd do is a fuel pressure test, the school's shop should have a fuel pressure gauge. you can jumper the fuel pump relay to force the pumps to run to do this test, should be about 43PSI above manifold vacuum (which is 0 if the car isn't running).

most 740's have two fuel pumps, one in the gas tank that primes the main pump thats under the car. the cars will run with the in-tank pump dead and a half tank or more of gas, just poorly and the main pump will be noisy. they won't run at all if the main pump is dead.

 

I had a '87 740 that I put more than 400,000 miles on, the best car I ever owned.

You should hear that fuel pump run for a few seconds when you try to start it. If not the fuel pump may be out. I have a fuel relay that will likely fit it that you are welcome to, just pm me.

Hope you get it started and welcome to the site.

 

Got some new and exciting news... I think. I couldn't get my hands on a fuel pressure tester nor could I find the port to plug it into on the engine. But. Using a jumper wire I pulled the fuel pump relay Ans jumped 30 to 87/2 and heard the fuel pump turn on. Tried to start. Nothing. Then I jumped 30 to 87/1 and the car started up and ran perfect. I didn't let it go for long as I've heard this is dangerous to do to electronics. Am I looking at a fuel pump relay that looks good but isn't functioning? I went ahead and ordered it but it wont be in until tomorrow. Think this may do the trick?

 

on a volvo LH system, you disconnect the fuel hose from the back of the fuel rail on the engine, and connect the fuel pressure regulator via a 'T' fitting.

re: that relay...

87/1 is actuated by grounding 86/1... so its probably worth sticking a volt meter between 30 (power) and 86/1, and seeing if you get 12V across those two pins when the ignition is switched on. if you DONT, then something is funky with the wiring or the ECU (ECU pin 21 provides that ground). if you do, then your problem is very likely the relay itself. get a 'good' one, KAE or Stebel or something, not a chinese cheapest-you-can-find. FCP has the KAE for $25. Volvo Fuel Pump Relay White (240 740 760 780 940) KAE 3523608 | FCP Euro

btw, jumping the relays specifically like this isn't going to harm the electronics, you're just turning 'on' the fuel injection system... the only bad thing is that they wouldn't turn OFF when you switch off the key, and would then drain the battery.

 

So got the new fuel pump relay.. hooked it up no start. So i swapped back in the Old ECU and it started right up, and idled for about ten minutes before i shut it down. Old ECU works? the only thing its doing is idling rough, but when i rev it its steady. also a slight metallic whining noise while its idling too.. Kinda confused at all of this, maybe the garage the guy i bought it from went to was wrong about the ECU...

 

ECU's tend to be pretty darn reliable. fuel pump relays less so

 

You should also replace the relay (radio suppression) that is mounted on the radiator fill bottle. The controls the FI nozzles.

 

to clarify the radio suppression relay, as the name is probably confusing...

240's didn't have them or need them as the main fuel injection/fuel pump relay was over behind the glovebox. on the 740, they moved all the relays to a central panel behind the glovebox, and directly under the radio... this had the unfortunate side effect of causing radio interference (mostly AM) due to the high current pulses to the fuel injectors running through the wiring and this relay, so they put another relay under the hood to switch the power to the injectors, this relay is turned on by the main fuel injection relay, and is known a the 'radio suppression relay'.

note, these relays just turn on the power to the injection system and the fuel injectors, they do NOT fire the injectors, thats done via transistors in the ECU which ground the injectors for each injection pulse.

 

So here is where I'm at today. I replaced the fuel pump relay the mass air meter and the CPS. New plugs and wires. Fresh oil. The ecu I got off eBay would start the car but it would immeadiatly die. Hooked old ecu up and the car runs. Idle is rough but acceleration is good. I'm getting codes though. 1-3-2 and 2-2-1. Could my rough idle be because of this? Also I hear every injector clicking good. Did the old ecu not work because it needs flashed? Or is the original ecu fine and its something different? I'm making progress and really appreciate this forum and you guys! Thanks.

 

Ah! Also. I let the car run for about twenty minutes yesterday. When I turned it off it wouldn't start back up. Waited a few hours... started right up.

 

after reading those codes, did you reset/clear them? the procedure is on the 7xx/9xx FAQ on numerous sites.

do the codes come back?

I don't like just shotgun replacing stuff without diagnosing the problem first. note there's a lot of subtly different ECUs, and only certain ones work in a given car.

 

Yeah I cleared the codes. They come right back. Just on port two of the diagnostic thing. No codes on port six.

 

wait. code 1-3-2 is 'battery voltage too low or high' ?? take a volt meter, read the voltage across the battery with the engine off, and with it idling. they _should_ be 12.something and 13.something. if the ECU is seeing low or high voltage, I'd wonder why... maybe its an issue with the power wiring to the ECU (which goes through the fuel injection+pump relay). maybe its a bad ground at the ECU.

 

At a loss now guys. Its throwing the mass air sensor code. The sensor is brand new, however car wont run any differently if I unplug it. Still rough. After it warms up it still idles rough and if I turn it off it wont start back up till its cold again.

 

this 'brand new' MAF... Volvo? bosch ? aftermarket? new or refurbished or used? are you sure its the right part number for your exact year/model car?

previously, you said codes 1-3-2 and 2-2-1, thats 'battery voltage low or high', and 'fuel trim too lean at part load'.

the battery low or high fault could be causing everything else to go wonky. please carefully read my prior post on this.

now, if you gave us the wrong codes last time, could you please give us the actual codes you're getting now?

 

Exact codes 132, 221, and 121. Mass air meter was Bosch. Refurbished I believe. It was a direct match to my vehicle. Pulled those codes ten minutes ago Just so you know its up to date.

 

well, I've never run into that incorrect battery voltage fault before, but if thats really the case, all bets are off the table til that one is cleared. I believe I'd be first checking that the battery and alternator voltage are correct (about 12.7V across the battery if its fully charged and has been resting an hour or more, and about 13.9V if the engine is running). if thats NOT the case, sort that out first. if the battery and alternator are good, tehn I'd be checking the voltages at the ECU socket, I think, and checking the grounds.

 

hi guys n girls need help or i will go crackers i have a volvo s40 related problem to which i hope someone can help me ahem....i had my my car m.o.t recently and was happy n thought nice one,got my keys back went to my car fired it up n the gearstick was shaking n the steering wheel was shaking like mad too,revs were below 1000 rpm so i brought the mechanic back out n he said it was strange of it to do that,so he revved it n he said it was mis firing so i got him to change the spark plugs today n collected it AGAIN!! the bloke said he drove round in it today n it was perfect,so i drove it to my mates house which is half an hour away,parked it up for 20 mins fired it up again AND LOW N BEHOLD IT STARTED SHAKING AGAIN ARRRGH the stress!!! so i had to try n drive it the power was dying on me i couldnt do no more than 30 mph was really worrying as the car started to stink i manged to get home ...just parked it up n it stunk of petrol and smoke was coming out of the car,...so due to the no power in the car do i need to replace my coil pack? and can i use a s40 1.6 coil pack to go into a s40 2l? coz i have replaced my plugs which were the wrong type by the way, plaese someone help coz i dont wanna give up my car

 

there's a whole seperate section of this forum for S40's, they are *COMPLETELY* different cars than the classic 240/740/940 covered in this forum.

S40 -> Volvo S40 - Volvo Forums - Volvo Enthusiasts Forum

also, you should start a new thread for a new car and new problem, and not piggyback on a old thread, as that just confuses things.