89 2wd van, codes 2 - 5 and 6

[mahleek87]

The other night while I was driving my recently acquired 89 van 2wd the check engine light came on for a few minutes and then went away. Hasnt been back on since but I was curious to check the codes and I found that I get 2 blinks 5 blinks and then 6 blinks

2- air flow meter?

5- oxygen sensor? (I am getting bad gas mileage so I wonder 18-19mpg)

6- RPM signal?

[timsrv]

There are no single digit codes on 88 - 89 vans. Codes start at 12 & end on 51. I'm guessing you might be seeing codes 25 & 26. If so, there's a good chance it needs a new o2 sensor. Tim

Here's a PDF of 88 - 89 trouble codes:

[mahleek87]

Ahh interesting. In that case I got 25 and 26.

2 flashes and then 5 flashes


2 flashes and 6 flashes.

Says it's running rich. I believe it is. Getting bad mpg. I just glanced over and saw the dist cap and wires are not oem, wonder if the rest isn't either. (Coil) etc.

[mahleek87]

If the 89 van has 2 o2 sensors. do they both need to be replaced?

also what brand is good? Bosch? Will it have the same connector as the van?

[timsrv]

I like Denso, but other brands are good too. Read my post on where/how to buy o2 sensors: http://www.toyotavantech.com/forum/showthread.php?415-Oxygen-sensor-part-number.

The primary sensor is the most important & also the most likely to fail. Not a bad idea to do both, but if you're on a budget you could probably get by with just the primary. Tim

[mahleek87]

About 3 weeks ago I got the oxygen sensor replaced by a master tech at a
toyota dealership around here in maryland. He's been working at that dealership for over 20 years so they let him do side jobs after 5pm. Which means I get a good deal. The oxygen sensor did eliminate the check engine light immediately once it was replaced. I also had him replace my transmission pan gasket. All for $80 in labor. Not bad at all.

i made this short clip of him driving the van in next to it's fellow
toyotas the clip is really short I didn't want him to think I was stalking him. Next time I'll make more but it's always fun to come here because all the mechanics crowd around the van and share stories of working on them or how they haven't seen one in years or ever.

One guy shared an interesting story how he replaced an ecu in a van because the ecu had a bullet hole through it. maybe some road rage transpired to someone trying to shoot the driver. Interesting

here is the link

http://youtu.be/4hFZKz_wV10

[Jdelgado]

I’m currently trying to diagnose code 25 (Air fuel ratio: lean) on the 89 2WD Van.

Just replaced and calibrated the TPS (Beck) + Pigtail harness, 02 sensors (Denso), intake boot, air filter, and a new catalytic convertor (Magnaflow).
I even swapped a good ECU and AFM for testing purposes and code came back on both sets.

When I crank the engine it starts up great (hot or very cold) idles smooth for about 30-40 seconds and immediately starts to run rough to the point of stalling if I don’t give it gas. After giving it a little gas all is good and drives great, when I put it in park it seems to have a high idle. Not sure if either issues are related but seemed worth mentioning. All vacuum lines seem good as well.

Other parts I’ve replaced the last few months fuel pump, fuel pressure regulator, fuel filter, dampener, and water temp sensor (all Denso / Toyota parts). Earlier in the year I put in new injectors, exhaust manifold, Denso alternator, plugs + wires, BVSV, cap + Rotor and even rebuilt the starter.

Any help would be appreciated, Feeling pretty stumped :dizzy:

Thank you

[boogieman]

id get a fuel pressure gauge on there 1st, thats alot of new parts...and i have to say new denso may not be the same quality as it used to be...

[timsrv]

Have you thoroughly checked the throttle body rubber intake tube for cracks? With the van idling give it a squeeze. If the van stalls, then it's likely that tube. Tim

[Jdelgado]

Yeah, I definitely need to get a fuel pressure gauge on there and see what numbers I get.



My previous one had a a tear on the throttle body side, and was replaced with a very good used one.
Looked great all around but i'll give it a squeeze and see if anything happens :)

anything else I should check out?

[timsrv]

You might also consider installing a wide band O2 sensor and mixture gauge as this will allow you to view and adjust the mixture correctly. Check out this thread: https://www.toyotavantech.com/forum/showthread.php?704-Idle-adjustment-question. The last couple of pages have some good content. Tim

[Jdelgado]

Definitely considering putting one in now, In the mean time i'll continue to to check for any vacuum leaks. I squeezed the intake and nothing changed, I feel like i'm overlooking a leak somewhere.
Yesterday when I drove the van it had a very high idle when parked / in neutral (I believe caused by leak) and when I went from park to reverse it jerked pretty hard (it happens intimately, today its been smooth) :cnfsd:

[Jdelgado]

Issues has been resolved. I had overlooked one vacuum line (Doh!) the line that connects the IAC valve to one of those little ports on the side. It had popped off the plastic port where I couldn't see it.
plugged it back in and it fixed the code 25, high idle, and stalling after start up. Out of curiosity when would the IAC valve need to be replaced on these vans?

[boogieman]

are you taking about the idle speed control(isc) vsv in between the manifold and airbox? or the big idle air.control valve in the clamshell?

[Jdelgado]

10736

This one

[89van]

Ello, hope you don't mind me necromancing one of these ol' threads but I got around to checking the OBD1 on my van [also an 89 2wd] (very interesting process compared to nowadays OBD2) and shes throwing: 2-5 (Code 25: Lean) blinks and nothing else.

So, where should I start for diagnosing? Knew about the lean mix (changed the plugs <1500 miles ago after its 3 year hibernation and they were fuzzy indicating it was running lean, and very oily probably from a bad valve cover gasket which is its own issue I should resolve).

Thanks! :thmbup::silvervan: