4AGE problem: EFI or ECU??

scotianbill · 06-13-2007, 12:04 PM

Hi all,

I have a problem with my 1987 4AGE MR2 and it is driving me insane...

The car starts fine, then after 3 seconds, it stalls. It does this everytime. Almost like it is getting no gas.

I originally thought it was the ignitor module and that the fuel pump was getting shut off, but since replacing the ignitor, it is still doing the same thing.
I have verified the wiring and everything else looks good.

What else can it be? The actual distributer? The EFI relay? Maybe the MAP sensor?

Can anyone help? It is a real shame to not be driving this car..

Thanks

mr220v · 06-13-2007, 12:17 PM

There is a switch in the airflow meter that engages the fuelpump once the afm opens.

To test this, do two things.

1. Take a piece of wire, and jumper pins +b and Fp on your diagnostic connector. This will cause the fuel pump to run continuously. At this point, if the afm switch was the problem, the car should run.

2. With the ignition on, push on the afm's metering door. You should hear the fuelpump cut on. If it doesn't, then this indicates a problem with the switch.

Also, if you have a major air leak between the afm and the throttlebody, this can cause an overly lean reading to the ecu causing this sort of problem.

scotianbill · 06-17-2007, 06:37 PM

A big thanks for the suggestions Mr220v...but still no go.

Any other ideas?

This is driving me insane.

Weasy2k · 06-18-2007, 04:08 PM

what happened when you did what he suggested? Did the fuel pump flow when jumped?

scotianbill · 06-29-2007, 07:10 PM

So sorry for the extended delay in responding...

It turns out that I was testing the MAF wrong, because I now know that it is the problem.
I managed to "borrow" a MAF from a Tercel that was on an extended stay at the local garage, and try it out. My MR2 worked fine..

So, I now had to get another but refused to pay the $650 that the dealer was asking.
I managed to find an old 1986 parts car that i bought for $200 and removed the MAF from that. But, now my car will idle, but when I give it more gas, it stalls. I took the MAF apart and it was very corroded inside.

I am now back to square 1, although I now know what the problem is. I just have to source a MAF.

What other years/models will work on my 4AGE? besides the now gone Tercel?

06-13-2007, 12:04 PM	#1 (permalink)
scotianbill No Skills Join Date: Jun 2007 Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	4AGE problem: EFI or ECU?? Hi all, I have a problem with my 1987 4AGE MR2 and it is driving me insane... The car starts fine, then after 3 seconds, it stalls. It does this everytime. Almost like it is getting no gas. I originally thought it was the ignitor module and that the fuel pump was getting shut off, but since replacing the ignitor, it is still doing the same thing. I have verified the wiring and everything else looks good. What else can it be? The actual distributer? The EFI relay? Maybe the MAP sensor? Can anyone help? It is a real shame to not be driving this car.. Thanks

06-18-2007, 04:08 PM	#4 (permalink)
Weasy2k 3.4L 10K RPM In the works Join Date: Mar 2005 Location: Vancouver, BC Posts: 8,886 Thanks: 34 Thanked 76 Times in 65 Posts iTrader Rating: (6/100% )	what happened when you did what he suggested? Did the fuel pump flow when jumped? __________________ -Johnny @ Sea2Sky Tuning - www.sea2skytuning.com http://www.mr2.com/forums/sea2sky-tu...-out-sale.html

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06-13-2007, 12:17 PM	#2 (permalink)
mr220v Beams Owners Group Join Date: Mar 2006 Posts: 1,318 Thanks: 13 Thanked 98 Times in 83 Posts iTrader Rating: (7/100% )	There is a switch in the airflow meter that engages the fuelpump once the afm opens. To test this, do two things. 1. Take a piece of wire, and jumper pins +b and Fp on your diagnostic connector. This will cause the fuel pump to run continuously. At this point, if the afm switch was the problem, the car should run. 2. With the ignition on, push on the afm's metering door. You should hear the fuelpump cut on. If it doesn't, then this indicates a problem with the switch. Also, if you have a major air leak between the afm and the throttlebody, this can cause an overly lean reading to the ecu causing this sort of problem.

06-17-2007, 06:37 PM	#3 (permalink)
scotianbill No Skills Join Date: Jun 2007 Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	A big thanks for the suggestions Mr220v...but still no go. Any other ideas? This is driving me insane.

06-29-2007, 07:10 PM	#5 (permalink)
scotianbill No Skills Join Date: Jun 2007 Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	So sorry for the extended delay in responding... It turns out that I was testing the MAF wrong, because I now know that it is the problem. I managed to "borrow" a MAF from a Tercel that was on an extended stay at the local garage, and try it out. My MR2 worked fine.. So, I now had to get another but refused to pay the $650 that the dealer was asking. I managed to find an old 1986 parts car that i bought for $200 and removed the MAF from that. But, now my car will idle, but when I give it more gas, it stalls. I took the MAF apart and it was very corroded inside. I am now back to square 1, although I now know what the problem is. I just have to source a MAF. What other years/models will work on my 4AGE? besides the now gone Tercel?