GM Repair Questions? Ask a Mechanic for Answers ASAP
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Refer to this wiring diagram, click here. The throttle body assembly is equipped with 1 (4-cylinder engines) or 2 (V6 engines) electronic fuel injectors in order to supply fuel to regulate the air/fuel mixture. All fuel injection and ignition functions are regulated by the computer control module, which is sometimes also referred to as the ECM, PCM or VCM.
First of all you need a noid light to check for a pulse. A voltmeter will not work, neither will a 12 volt test light. The voltage on the pulse or ground side is very small and very quick, a noid light is needed. usually you can find one for $5 or an entire kit for $25.
Have you check for any codes? If after you get a noid light and you do have a pulse and you do have fuel pressure then the injector is clogged. If still no pulse, let me know.
The 1988 Chevrolet Truck S10 P/U 2WD 2.5L TBI 4cyl vin E fuel injector is part(NNN) NNN-NNNN.
The 1992 GMC Truck Sonoma 2WD 2.5L TBI 4cyl vin A fuel injector is(NNN) NNN-NNNN.
I don't know if they will interchange.
Anyhow, let me know when you check for a pulse an any codes.
Compnine also lists the 92 sonoma with a fuel injector as a ACDelco #217-338.
On the 88 s10 the fuel injector is a ACDelco #217-336.
Which set was that cause I was thinking of buying this set myself here,
You know something, afterall this question should have been in chevy. Oh well, nonetheless I see autozone is now selling computers for $79, it used to be only napa that had them.
There are all 3 important, at least the map sensor could prevent it from starting. I would fix them first. The code 24 did refer to the speed sensor like you said, the 25 to the Manifold Air Temperature Sensor Circuit and 34 to a Manifold Absolute Pressure Sensor Malfunction.
Usually Chilton doesn't have any diagnostic info earlier than 1995 and that OBDI. Let me check! BRB.
Try to clear those codes first, then check if there are cleared then try to start it nd see if they all 3 come back. Check for a vacuum hose off going to and from the map sensor, check all fuses and check anything going to or from that speed sensor and manifold air temp sensor, look for burnt wires and burnt smelling parts while I look up any test procedures for them 3 circuits.
Stored trouble codes must be cleared with the ignition switch OFF. NEVER attempt to clear codes while the ignition switch is in the ON position or the computer module will likely be destroyed. Remove the ECMB fuse for at least 5 seconds, then reinstall the fuse.
All I could find is the operation of the Manifold Air Temperature Sensor and testing the speed sensor. Click here. I see autozone sells the map sensor for $41.99.
The Manifold Air Temperature Sensor for $15.99.
The speed sensor give me 1 minute.
Rockauto has the speed sensor for $52.89.
The only one that might cause it to shutdown and not start would be the map sensor. I remember pulling the vacuum hose off a map sensor and the engine would stall.
I looked all over and all I could find is a vacuum diagram of a 1989 2.5, click here for fed and here for california. That is probably the egr solenoid.
I see the ac delco is actually listed as #88999194.
88999194 also fitshttp://www.compnine.com/pnmouseover.php?pn=88999194
Yeah, I know what you mean. Condemning an ECM is always tricky, the best thing to do is like you said borrow a good one or at least rule out everything else. I suppose it could also be a bad connection from the injector to the ecm. Anyhow, let me know today.
Are you sure you didn't miss a number when writing down that part number on the ecm? I just got an email from ebay about my favorite sellers and I remember this seller sells ecm's and then I looked to see if he had yours and he does but it says it is a(NNN) NNN-NNNNnot a 122765. Looks like maybe you missed the 1. Anyhow, looks like it's about the same price as autozone, actually $10 more.
I found some here, too for $88,
Here, too under the ac delco part number,
Not seems odd, you were just mentioning a white wire that someone told you about and I said it may be the tach wire, now you say someone tried to hook the tach to that circuit.
Anyhow, I will try to find out if that circuit is supposed to ground or not with key off. I thought it would just be open. I am not going to promise you that my manuals will get into that that in depth but I will try.
I thought you were going to try the sonoma ecm on the s10?
Anyhow, try disconnecting those pink/black wires going to the egr solenoid just for now, plus I see another pink/black going back to the ecm.
1. Noting the polarity marked on the switch, connect a 12 volt battery and a voltmeter as shown in the illustration.
2. Insert a thin bladed tool against the magnet as shown.
I saw this exact same test procedure posted somewhere, but the illustration is missing
I'll see if its obvious how to connect when looking at it.
You are on the ball. I noticed that, too. Chilton is famous for that. I have had them refer me to tsb's that they don't have. Then sometimes they refer you to section 6 or something like that but they were talking about a section when it was in book form, the website lists it completely different.
Hopefully there is just 2 connections.